Merge pull request #258 from SeaQL/active-enum

Enumeration

Cargo.toml

@@ -30,7 +30,7 @@ futures-util = { version = "^0.3" }
 log = { version = "^0.4", optional = true }
 rust_decimal = { version = "^1", optional = true }
 sea-orm-macros = { version = "^0.3.1", path = "sea-orm-macros", optional = true }
-sea-query = { version = "^0.18.0", features = ["thread-safe"] }
+sea-query = { version = "^0.18.0", git = "https://github.com/SeaQL/sea-query.git", features = ["thread-safe"] }
 sea-strum = { version = "^0.21", features = ["derive", "sea-orm"] }
 serde = { version = "^1.0", features = ["derive"] }
 serde_json = { version = "^1", optional = true }

sea-orm-macros/src/derives/active_enum.rs

@@ -0,0 +1,286 @@
+use heck::CamelCase;
+use proc_macro2::TokenStream;
+use quote::{quote, quote_spanned};
+use syn::{punctuated::Punctuated, token::Comma, Lit, LitInt, LitStr, Meta};
+
+enum Error {
+    InputNotEnum,
+    Syn(syn::Error),
+    TT(TokenStream),
+}
+
+struct ActiveEnum {
+    ident: syn::Ident,
+    enum_name: String,
+    rs_type: TokenStream,
+    db_type: TokenStream,
+    is_string: bool,
+    variants: Vec<ActiveEnumVariant>,
+}
+
+struct ActiveEnumVariant {
+    ident: syn::Ident,
+    string_value: Option<LitStr>,
+    num_value: Option<LitInt>,
+}
+
+impl ActiveEnum {
+    fn new(input: syn::DeriveInput) -> Result<Self, Error> {
+        let ident_span = input.ident.span();
+        let ident = input.ident;
+
+        let mut enum_name = ident.to_string().to_camel_case();
+        let mut rs_type = Err(Error::TT(quote_spanned! {
+            ident_span => compile_error!("Missing macro attribute `rs_type`");
+        }));
+        let mut db_type = Err(Error::TT(quote_spanned! {
+            ident_span => compile_error!("Missing macro attribute `db_type`");
+        }));
+        for attr in input.attrs.iter() {
+            if let Some(ident) = attr.path.get_ident() {
+                if ident != "sea_orm" {
+                    continue;
+                }
+            } else {
+                continue;
+            }
+            if let Ok(list) = attr.parse_args_with(Punctuated::<Meta, Comma>::parse_terminated) {
+                for meta in list.iter() {
+                    if let Meta::NameValue(nv) = meta {
+                        if let Some(name) = nv.path.get_ident() {
+                            if name == "rs_type" {
+                                if let Lit::Str(litstr) = &nv.lit {
+                                    rs_type = syn::parse_str::<TokenStream>(&litstr.value())
+                                        .map_err(Error::Syn);
+                                }
+                            } else if name == "db_type" {
+                                if let Lit::Str(litstr) = &nv.lit {
+                                    let s = litstr.value();
+                                    match s.as_ref() {
+                                        "Enum" => {
+                                            db_type = Ok(quote! {
+                                                Enum(Self::name(), Self::values())
+                                            })
+                                        }
+                                        _ => {
+                                            db_type = syn::parse_str::<TokenStream>(&s)
+                                                .map_err(Error::Syn);
+                                        }
+                                    }
+                                }
+                            } else if name == "enum_name" {
+                                if let Lit::Str(litstr) = &nv.lit {
+                                    enum_name = litstr.value();
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        let variant_vec = match input.data {
+            syn::Data::Enum(syn::DataEnum { variants, .. }) => variants,
+            _ => return Err(Error::InputNotEnum),
+        };
+
+        let mut is_string = false;
+        let mut is_int = false;
+        let mut variants = Vec::new();
+        for variant in variant_vec {
+            let variant_span = variant.ident.span();
+            let mut string_value = None;
+            let mut num_value = None;
+            for attr in variant.attrs.iter() {
+                if let Some(ident) = attr.path.get_ident() {
+                    if ident != "sea_orm" {
+                        continue;
+                    }
+                } else {
+                    continue;
+                }
+                if let Ok(list) = attr.parse_args_with(Punctuated::<Meta, Comma>::parse_terminated)
+                {
+                    for meta in list {
+                        if let Meta::NameValue(nv) = meta {
+                            if let Some(name) = nv.path.get_ident() {
+                                if name == "string_value" {
+                                    if let Lit::Str(lit) = nv.lit {
+                                        is_string = true;
+                                        string_value = Some(lit);
+                                    }
+                                } else if name == "num_value" {
+                                    if let Lit::Int(lit) = nv.lit {
+                                        is_int = true;
+                                        num_value = Some(lit);
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+
+            if is_string && is_int {
+                return Err(Error::TT(quote_spanned! {
+                    ident_span => compile_error!("All enum variants should specify the same `*_value` macro attribute, either `string_value` or `num_value` but not both");
+                }));
+            }
+
+            if string_value.is_none() && num_value.is_none() {
+                return Err(Error::TT(quote_spanned! {
+                    variant_span => compile_error!("Missing macro attribute, either `string_value` or `num_value` should be specified");
+                }));
+            }
+
+            variants.push(ActiveEnumVariant {
+                ident: variant.ident,
+                string_value,
+                num_value,
+            });
+        }
+
+        Ok(ActiveEnum {
+            ident,
+            enum_name,
+            rs_type: rs_type?,
+            db_type: db_type?,
+            is_string,
+            variants,
+        })
+    }
+
+    fn expand(&self) -> syn::Result<TokenStream> {
+        let expanded_impl_active_enum = self.impl_active_enum();
+
+        Ok(expanded_impl_active_enum)
+    }
+
+    fn impl_active_enum(&self) -> TokenStream {
+        let Self {
+            ident,
+            enum_name,
+            rs_type,
+            db_type,
+            is_string,
+            variants,
+        } = self;
+
+        let variant_idents: Vec<syn::Ident> = variants
+            .iter()
+            .map(|variant| variant.ident.clone())
+            .collect();
+
+        let variant_values: Vec<TokenStream> = variants
+            .iter()
+            .map(|variant| {
+                let variant_span = variant.ident.span();
+
+                if let Some(string_value) = &variant.string_value {
+                    let string = string_value.value();
+                    quote! { #string }
+                } else if let Some(num_value) = &variant.num_value {
+                    quote! { #num_value }
+                } else {
+                    quote_spanned! {
+                        variant_span => compile_error!("Missing macro attribute, either `string_value` or `num_value` should be specified");
+                    }
+                }
+            })
+            .collect();
+
+        let val = if *is_string {
+            quote! { v.as_ref() }
+        } else {
+            quote! { v }
+        };
+
+        quote!(
+            #[automatically_derived]
+            impl sea_orm::ActiveEnum for #ident {
+                type Value = #rs_type;
+
+                fn name() -> String {
+                    #enum_name.to_owned()
+                }
+
+                fn to_value(&self) -> Self::Value {
+                    match self {
+                        #( Self::#variant_idents => #variant_values, )*
+                    }
+                    .to_owned()
+                }
+
+                fn try_from_value(v: &Self::Value) -> Result<Self, sea_orm::DbErr> {
+                    match #val {
+                        #( #variant_values => Ok(Self::#variant_idents), )*
+                        _ => Err(sea_orm::DbErr::Type(format!(
+                            "unexpected value for {} enum: {}",
+                            stringify!(#ident),
+                            v
+                        ))),
+                    }
+                }
+
+                fn db_type() -> sea_orm::ColumnDef {
+                    sea_orm::ColumnType::#db_type.def()
+                }
+            }
+
+            #[automatically_derived]
+            #[allow(clippy::from_over_into)]
+            impl Into<sea_orm::sea_query::Value> for #ident {
+                fn into(self) -> sea_orm::sea_query::Value {
+                    <Self as sea_orm::ActiveEnum>::to_value(&self).into()
+                }
+            }
+
+            #[automatically_derived]
+            impl sea_orm::TryGetable for #ident {
+                fn try_get(res: &sea_orm::QueryResult, pre: &str, col: &str) -> Result<Self, sea_orm::TryGetError> {
+                    let value = <<Self as sea_orm::ActiveEnum>::Value as sea_orm::TryGetable>::try_get(res, pre, col)?;
+                    <Self as sea_orm::ActiveEnum>::try_from_value(&value).map_err(sea_orm::TryGetError::DbErr)
+                }
+            }
+
+            #[automatically_derived]
+            impl sea_orm::sea_query::ValueType for #ident {
+                fn try_from(v: sea_orm::sea_query::Value) -> Result<Self, sea_orm::sea_query::ValueTypeErr> {
+                    let value = <<Self as sea_orm::ActiveEnum>::Value as sea_orm::sea_query::ValueType>::try_from(v)?;
+                    <Self as sea_orm::ActiveEnum>::try_from_value(&value).map_err(|_| sea_orm::sea_query::ValueTypeErr)
+                }
+
+                fn type_name() -> String {
+                    <<Self as sea_orm::ActiveEnum>::Value as sea_orm::sea_query::ValueType>::type_name()
+                }
+
+                fn column_type() -> sea_orm::sea_query::ColumnType {
+                    <Self as sea_orm::ActiveEnum>::db_type()
+                        .get_column_type()
+                        .to_owned()
+                        .into()
+                }
+            }
+
+            #[automatically_derived]
+            impl sea_orm::sea_query::Nullable for #ident {
+                fn null() -> sea_orm::sea_query::Value {
+                    <<Self as sea_orm::ActiveEnum>::Value as sea_orm::sea_query::Nullable>::null()
+                }
+            }
+        )
+    }
+}
+
+pub fn expand_derive_active_enum(input: syn::DeriveInput) -> syn::Result<TokenStream> {
+    let ident_span = input.ident.span();
+
+    match ActiveEnum::new(input) {
+        Ok(model) => model.expand(),
+        Err(Error::InputNotEnum) => Ok(quote_spanned! {
+            ident_span => compile_error!("you can only derive ActiveEnum on enums");
+        }),
+        Err(Error::TT(token_stream)) => Ok(token_stream),
+        Err(Error::Syn(e)) => Err(e),
+    }
+}

sea-orm-macros/src/derives/entity_model.rs

@@ -1,7 +1,7 @@
 use crate::util::{escape_rust_keyword, trim_starting_raw_identifier};
 use heck::CamelCase;
 use proc_macro2::{Ident, Span, TokenStream};
-use quote::quote;
+use quote::{format_ident, quote, quote_spanned};
 use syn::{
     parse::Error, punctuated::Punctuated, spanned::Spanned, token::Comma, Attribute, Data, Fields,
     Lit, Meta,
@@ -193,8 +193,8 @@ pub fn expand_derive_entity_model(data: Data, attrs: Vec<Attribute>) -> syn::Res
                         primary_keys.push(quote! { #field_name });
                     }
 
-                    let field_type = match sql_type {
+                    let col_type = match sql_type {
-                        Some(t) => t,
+                        Some(t) => quote! { sea_orm::prelude::ColumnType::#t.def() },
                         None => {
                             let field_type = &field.ty;
                             let temp = quote! { #field_type }
@@ -206,7 +206,7 @@ pub fn expand_derive_entity_model(data: Data, attrs: Vec<Attribute>) -> syn::Res
                             } else {
                                 temp.as_str()
                             };
-                            match temp {
+                            let col_type = match temp {
                                 "char" => quote! { Char(None) },
                                 "String" | "&str" => quote! { String(None) },
                                 "u8" | "i8" => quote! { TinyInteger },
@@ -229,16 +229,24 @@ pub fn expand_derive_entity_model(data: Data, attrs: Vec<Attribute>) -> syn::Res
                                 "Decimal" => quote! { Decimal(None) },
                                 "Vec<u8>" => quote! { Binary },
                                 _ => {
-                                    return Err(Error::new(
+                                    // Assumed it's ActiveEnum if none of the above type matches
-                                        field.span(),
+                                    quote! {}
-                                        format!("unrecognized type {}", temp),
-                                    ))
                                 }
+                            };
+                            if col_type.is_empty() {
+                                let field_span = field.span();
+                                let ty = format_ident!("{}", temp);
+                                let def = quote_spanned! { field_span => {
+                                    <#ty as ActiveEnum>::db_type()
+                                }};
+                                quote! { #def }
+                            } else {
+                                quote! { sea_orm::prelude::ColumnType::#col_type.def() }
                             }
                         }
                     };
 
-                    let mut match_row = quote! { Self::#field_name => sea_orm::prelude::ColumnType::#field_type.def() };
+                    let mut match_row = quote! { Self::#field_name => #col_type };
                     if nullable {
                         match_row = quote! { #match_row.nullable() };
                     }

sea-orm-macros/src/derives/mod.rs

@@ -1,3 +1,4 @@
+mod active_enum;
 mod active_model;
 mod active_model_behavior;
 mod column;
@@ -9,6 +10,7 @@ mod model;
 mod primary_key;
 mod relation;
 
+pub use active_enum::*;
 pub use active_model::*;
 pub use active_model_behavior::*;
 pub use column::*;

sea-orm-macros/src/lib.rs

@@ -492,6 +492,41 @@ pub fn derive_active_model_behavior(input: TokenStream) -> TokenStream {
     }
 }
 
+/// A derive macro to implement `sea_orm::ActiveEnum` trait for enums.
+///
+/// # Limitations
+///
+/// This derive macros can only be used on enums.
+///
+/// # Macro Attributes
+///
+/// All macro attributes listed below have to be annotated in the form of `#[sea_orm(attr = value)]`.
+///
+/// - For enum
+///     - `rs_type`: Define `ActiveEnum::Value`
+///         - Possible values: `String`, `i8`, `i16`, `i32`, `i64`, `u8`, `u16`, `u32`, `u64`
+///         - Note that value has to be passed as string, i.e. `rs_type = "i8"`
+///     - `db_type`: Define `ColumnType` returned by `ActiveEnum::db_type()`
+///         - Possible values: all available enum variants of `ColumnType`, e.g. `String(None)`, `String(Some(1))`, `Integer`
+///         - Note that value has to be passed as string, i.e. `db_type = "Integer"`
+///     - `enum_name`: Define `String` returned by `ActiveEnum::name()`
+///         - This attribute is optional with default value being the name of enum in camel-case
+///         - Note that value has to be passed as string, i.e. `db_type = "Integer"`
+///
+/// - For enum variant
+///     - `string_value` or `num_value`:
+///         - For `string_value`, value should be passed as string, i.e. `string_value = "A"`
+///         - For `num_value`, value should be passed as integer, i.e. `num_value = 1` or `num_value = 1i32`
+///         - Note that only one of it can be specified, and all variants of an enum have to annotate with the same `*_value` macro attribute
+#[proc_macro_derive(DeriveActiveEnum, attributes(sea_orm))]
+pub fn derive_active_enum(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as DeriveInput);
+    match derives::expand_derive_active_enum(input) {
+        Ok(ts) => ts.into(),
+        Err(e) => e.to_compile_error().into(),
+    }
+}
+
 /// Convert a query result into the corresponding Model.
 ///
 /// ### Usage

src/database/statement.rs

@@ -82,6 +82,15 @@ macro_rules! build_any_stmt {
     };
 }
 
+macro_rules! build_postgres_stmt {
+    ($stmt: expr, $db_backend: expr) => {
+        match $db_backend {
+            DbBackend::Postgres => $stmt.to_string(PostgresQueryBuilder),
+            DbBackend::MySql | DbBackend::Sqlite => unimplemented!(),
+        }
+    };
+}
+
 macro_rules! build_query_stmt {
     ($stmt: ty) => {
         impl StatementBuilder for $stmt {
@@ -114,3 +123,18 @@ build_schema_stmt!(sea_query::TableDropStatement);
 build_schema_stmt!(sea_query::TableAlterStatement);
 build_schema_stmt!(sea_query::TableRenameStatement);
 build_schema_stmt!(sea_query::TableTruncateStatement);
+
+macro_rules! build_type_stmt {
+    ($stmt: ty) => {
+        impl StatementBuilder for $stmt {
+            fn build(&self, db_backend: &DbBackend) -> Statement {
+                let stmt = build_postgres_stmt!(self, db_backend);
+                Statement::from_string(*db_backend, stmt)
+            }
+        }
+    };
+}
+
+build_type_stmt!(sea_query::extension::postgres::TypeAlterStatement);
+build_type_stmt!(sea_query::extension::postgres::TypeCreateStatement);
+build_type_stmt!(sea_query::extension::postgres::TypeDropStatement);

src/entity/active_enum.rs

@@ -0,0 +1,308 @@
+use crate::{ColumnDef, DbErr, Iterable, TryGetable};
+use sea_query::{Nullable, Value, ValueType};
+
+/// A Rust representation of enum defined in database.
+///
+/// # Implementations
+///
+/// You can implement [ActiveEnum] manually by hand or use the derive macro [DeriveActiveEnum](sea_orm_macros::DeriveActiveEnum).
+///
+/// # Examples
+///
+/// Implementing it manually versus using the derive macro [DeriveActiveEnum](sea_orm_macros::DeriveActiveEnum).
+///
+/// > See [DeriveActiveEnum](sea_orm_macros::DeriveActiveEnum) for the full specification of macro attributes.
+///
+/// ```rust
+/// use sea_orm::entity::prelude::*;
+///
+/// // Using the derive macro
+/// #[derive(Debug, PartialEq, EnumIter, DeriveActiveEnum)]
+/// #[sea_orm(
+///     rs_type = "String",
+///     db_type = "String(Some(1))",
+///     enum_name = "category"
+/// )]
+/// pub enum DeriveCategory {
+///     #[sea_orm(string_value = "B")]
+///     Big,
+///     #[sea_orm(string_value = "S")]
+///     Small,
+/// }
+///
+/// // Implementing it manually
+/// #[derive(Debug, PartialEq, EnumIter)]
+/// pub enum Category {
+///     Big,
+///     Small,
+/// }
+///
+/// impl ActiveEnum for Category {
+///     // The macro attribute `rs_type` is being pasted here
+///     type Value = String;
+///
+///     // Will be atomically generated by `DeriveActiveEnum`
+///     fn name() -> String {
+///         "category".to_owned()
+///     }
+///
+///     // Will be atomically generated by `DeriveActiveEnum`
+///     fn to_value(&self) -> Self::Value {
+///         match self {
+///             Self::Big => "B",
+///             Self::Small => "S",
+///         }
+///         .to_owned()
+///     }
+///
+///     // Will be atomically generated by `DeriveActiveEnum`
+///     fn try_from_value(v: &Self::Value) -> Result<Self, DbErr> {
+///         match v.as_ref() {
+///             "B" => Ok(Self::Big),
+///             "S" => Ok(Self::Small),
+///             _ => Err(DbErr::Type(format!(
+///                 "unexpected value for Category enum: {}",
+///                 v
+///             ))),
+///         }
+///     }
+///
+///     fn db_type() -> ColumnDef {
+///         // The macro attribute `db_type` is being pasted here
+///         ColumnType::String(Some(1)).def()
+///     }
+/// }
+/// ```
+///
+/// Using [ActiveEnum] on Model.
+///
+/// ```
+/// use sea_orm::entity::prelude::*;
+///
+/// // Define the `Category` active enum
+/// #[derive(Debug, Clone, PartialEq, EnumIter, DeriveActiveEnum)]
+/// #[sea_orm(rs_type = "String", db_type = "String(Some(1))")]
+/// pub enum Category {
+///     #[sea_orm(string_value = "B")]
+///     Big,
+///     #[sea_orm(string_value = "S")]
+///     Small,
+/// }
+///
+/// #[derive(Clone, Debug, PartialEq, DeriveEntityModel)]
+/// #[sea_orm(table_name = "active_enum")]
+/// pub struct Model {
+///     #[sea_orm(primary_key)]
+///     pub id: i32,
+///     // Represents a db column using `Category` active enum
+///     pub category: Category,
+///     pub category_opt: Option<Category>,
+/// }
+///
+/// #[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+/// pub enum Relation {}
+///
+/// impl ActiveModelBehavior for ActiveModel {}
+/// ```
+pub trait ActiveEnum: Sized + Iterable {
+    /// Define the Rust type that each enum variant represents.
+    type Value: Into<Value> + ValueType + Nullable + TryGetable;
+
+    /// Get the name of enum
+    fn name() -> String;
+
+    /// Convert enum variant into the corresponding value.
+    fn to_value(&self) -> Self::Value;
+
+    /// Try to convert the corresponding value into enum variant.
+    fn try_from_value(v: &Self::Value) -> Result<Self, DbErr>;
+
+    /// Get the database column definition of this active enum.
+    fn db_type() -> ColumnDef;
+
+    /// Convert an owned enum variant into the corresponding value.
+    fn into_value(self) -> Self::Value {
+        Self::to_value(&self)
+    }
+
+    /// Get the name of all enum variants
+    fn values() -> Vec<Self::Value> {
+        Self::iter().map(Self::into_value).collect()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate as sea_orm;
+    use crate::{entity::prelude::*, *};
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn active_enum_string() {
+        #[derive(Debug, PartialEq, EnumIter)]
+        pub enum Category {
+            Big,
+            Small,
+        }
+
+        impl ActiveEnum for Category {
+            type Value = String;
+
+            fn name() -> String {
+                "category".to_owned()
+            }
+
+            fn to_value(&self) -> Self::Value {
+                match self {
+                    Self::Big => "B",
+                    Self::Small => "S",
+                }
+                .to_owned()
+            }
+
+            fn try_from_value(v: &Self::Value) -> Result<Self, DbErr> {
+                match v.as_ref() {
+                    "B" => Ok(Self::Big),
+                    "S" => Ok(Self::Small),
+                    _ => Err(DbErr::Type(format!(
+                        "unexpected value for Category enum: {}",
+                        v
+                    ))),
+                }
+            }
+
+            fn db_type() -> ColumnDef {
+                ColumnType::String(Some(1)).def()
+            }
+        }
+
+        #[derive(Debug, PartialEq, EnumIter, DeriveActiveEnum)]
+        #[sea_orm(
+            rs_type = "String",
+            db_type = "String(Some(1))",
+            enum_name = "category"
+        )]
+        pub enum DeriveCategory {
+            #[sea_orm(string_value = "B")]
+            Big,
+            #[sea_orm(string_value = "S")]
+            Small,
+        }
+
+        assert_eq!(Category::Big.to_value(), "B".to_owned());
+        assert_eq!(Category::Small.to_value(), "S".to_owned());
+        assert_eq!(DeriveCategory::Big.to_value(), "B".to_owned());
+        assert_eq!(DeriveCategory::Small.to_value(), "S".to_owned());
+
+        assert_eq!(
+            Category::try_from_value(&"A".to_owned()).err(),
+            Some(DbErr::Type(
+                "unexpected value for Category enum: A".to_owned()
+            ))
+        );
+        assert_eq!(
+            Category::try_from_value(&"B".to_owned()).ok(),
+            Some(Category::Big)
+        );
+        assert_eq!(
+            Category::try_from_value(&"S".to_owned()).ok(),
+            Some(Category::Small)
+        );
+        assert_eq!(
+            DeriveCategory::try_from_value(&"A".to_owned()).err(),
+            Some(DbErr::Type(
+                "unexpected value for DeriveCategory enum: A".to_owned()
+            ))
+        );
+        assert_eq!(
+            DeriveCategory::try_from_value(&"B".to_owned()).ok(),
+            Some(DeriveCategory::Big)
+        );
+        assert_eq!(
+            DeriveCategory::try_from_value(&"S".to_owned()).ok(),
+            Some(DeriveCategory::Small)
+        );
+
+        assert_eq!(Category::db_type(), ColumnType::String(Some(1)).def());
+        assert_eq!(DeriveCategory::db_type(), ColumnType::String(Some(1)).def());
+
+        assert_eq!(Category::name(), DeriveCategory::name());
+        assert_eq!(Category::values(), DeriveCategory::values());
+    }
+
+    #[test]
+    fn active_enum_derive_signed_integers() {
+        macro_rules! test_int {
+            ($ident: ident, $rs_type: expr, $db_type: expr, $col_def: ident) => {
+                #[derive(Debug, PartialEq, EnumIter, DeriveActiveEnum)]
+                #[sea_orm(rs_type = $rs_type, db_type = $db_type)]
+                pub enum $ident {
+                    #[sea_orm(num_value = 1)]
+                    Big,
+                    #[sea_orm(num_value = 0)]
+                    Small,
+                    #[sea_orm(num_value = -10)]
+                    Negative,
+                }
+
+                assert_eq!($ident::Big.to_value(), 1);
+                assert_eq!($ident::Small.to_value(), 0);
+                assert_eq!($ident::Negative.to_value(), -10);
+
+                assert_eq!($ident::try_from_value(&1).ok(), Some($ident::Big));
+                assert_eq!($ident::try_from_value(&0).ok(), Some($ident::Small));
+                assert_eq!($ident::try_from_value(&-10).ok(), Some($ident::Negative));
+                assert_eq!(
+                    $ident::try_from_value(&2).err(),
+                    Some(DbErr::Type(format!(
+                        "unexpected value for {} enum: 2",
+                        stringify!($ident)
+                    )))
+                );
+
+                assert_eq!($ident::db_type(), ColumnType::$col_def.def());
+            };
+        }
+
+        test_int!(I8, "i8", "TinyInteger", TinyInteger);
+        test_int!(I16, "i16", "SmallInteger", SmallInteger);
+        test_int!(I32, "i32", "Integer", Integer);
+        test_int!(I64, "i64", "BigInteger", BigInteger);
+    }
+
+    #[test]
+    fn active_enum_derive_unsigned_integers() {
+        macro_rules! test_uint {
+            ($ident: ident, $rs_type: expr, $db_type: expr, $col_def: ident) => {
+                #[derive(Debug, PartialEq, EnumIter, DeriveActiveEnum)]
+                #[sea_orm(rs_type = $rs_type, db_type = $db_type)]
+                pub enum $ident {
+                    #[sea_orm(num_value = 1)]
+                    Big,
+                    #[sea_orm(num_value = 0)]
+                    Small,
+                }
+
+                assert_eq!($ident::Big.to_value(), 1);
+                assert_eq!($ident::Small.to_value(), 0);
+
+                assert_eq!($ident::try_from_value(&1).ok(), Some($ident::Big));
+                assert_eq!($ident::try_from_value(&0).ok(), Some($ident::Small));
+                assert_eq!(
+                    $ident::try_from_value(&2).err(),
+                    Some(DbErr::Type(format!(
+                        "unexpected value for {} enum: 2",
+                        stringify!($ident)
+                    )))
+                );
+
+                assert_eq!($ident::db_type(), ColumnType::$col_def.def());
+            };
+        }
+
+        test_uint!(U8, "u8", "TinyInteger", TinyInteger);
+        test_uint!(U16, "u16", "SmallInteger", SmallInteger);
+        test_uint!(U32, "u32", "Integer", Integer);
+        test_uint!(U64, "u64", "BigInteger", BigInteger);
+    }
+}

src/entity/column.rs

@@ -1,5 +1,5 @@
 use crate::{EntityName, IdenStatic, Iterable};
-use sea_query::{DynIden, Expr, SeaRc, SelectStatement, SimpleExpr, Value};
+use sea_query::{Alias, BinOper, DynIden, Expr, SeaRc, SelectStatement, SimpleExpr, Value};
 use std::str::FromStr;
 
 /// Defines a Column for an Entity
@@ -62,6 +62,8 @@ pub enum ColumnType {
     Custom(String),
     /// A Universally Unique IDentifier that is specified in  RFC 4122
     Uuid,
+    /// `ENUM` data type with name and variants
+    Enum(String, Vec<String>),
 }
 
 macro_rules! bind_oper {
@@ -76,6 +78,25 @@ macro_rules! bind_oper {
     };
 }
 
+macro_rules! bind_oper_with_enum_casting {
+    ( $op: ident, $bin_op: ident ) => {
+        #[allow(missing_docs)]
+        fn $op<V>(&self, v: V) -> SimpleExpr
+        where
+            V: Into<Value>,
+        {
+            let val = Expr::val(v);
+            let col_def = self.def();
+            let col_type = col_def.get_column_type();
+            let expr = match col_type.get_enum_name() {
+                Some(enum_name) => val.as_enum(Alias::new(enum_name)),
+                None => val.into(),
+            };
+            Expr::tbl(self.entity_name(), *self).binary(BinOper::$bin_op, expr)
+        }
+    };
+}
+
 macro_rules! bind_func_no_params {
     ( $func: ident ) => {
         /// See also SeaQuery's method with same name.
@@ -128,8 +149,8 @@ pub trait ColumnTrait: IdenStatic + Iterable + FromStr {
         (self.entity_name(), SeaRc::new(*self) as DynIden)
     }
 
-    bind_oper!(eq);
+    bind_oper_with_enum_casting!(eq, Equal);
-    bind_oper!(ne);
+    bind_oper_with_enum_casting!(ne, NotEqual);
     bind_oper!(gt);
     bind_oper!(gte);
     bind_oper!(lt);
@@ -281,6 +302,13 @@ impl ColumnType {
             indexed: false,
         }
     }
+
+    pub(crate) fn get_enum_name(&self) -> Option<&String> {
+        match self {
+            ColumnType::Enum(s, _) => Some(s),
+            _ => None,
+        }
+    }
 }
 
 impl ColumnDef {
@@ -306,6 +334,11 @@ impl ColumnDef {
         self.indexed = true;
         self
     }
+
+    /// Get [ColumnType] as reference
+    pub fn get_column_type(&self) -> &ColumnType {
+        &self.col_type
+    }
 }
 
 impl From<ColumnType> for sea_query::ColumnType {
@@ -331,7 +364,7 @@ impl From<ColumnType> for sea_query::ColumnType {
             ColumnType::Money(s) => sea_query::ColumnType::Money(s),
             ColumnType::Json => sea_query::ColumnType::Json,
             ColumnType::JsonBinary => sea_query::ColumnType::JsonBinary,
-            ColumnType::Custom(s) => {
+            ColumnType::Custom(s) | ColumnType::Enum(s, _) => {
                 sea_query::ColumnType::Custom(sea_query::SeaRc::new(sea_query::Alias::new(&s)))
             }
             ColumnType::Uuid => sea_query::ColumnType::Uuid,

src/entity/mod.rs

@@ -95,6 +95,7 @@
 /// // to create an ActiveModel using the [ActiveModelBehavior]
 /// impl ActiveModelBehavior for ActiveModel {}
 /// ```
+mod active_enum;
 mod active_model;
 mod base_entity;
 mod column;
@@ -106,6 +107,7 @@ pub mod prelude;
 mod primary_key;
 mod relation;
 
+pub use active_enum::*;
 pub use active_model::*;
 pub use base_entity::*;
 pub use column::*;

src/entity/prelude.rs

@@ -1,14 +1,15 @@
 pub use crate::{
-    error::*, ActiveModelBehavior, ActiveModelTrait, ColumnDef, ColumnTrait, ColumnType,
+    error::*, ActiveEnum, ActiveModelBehavior, ActiveModelTrait, ColumnDef, ColumnTrait,
-    DatabaseConnection, DbConn, EntityName, EntityTrait, EnumIter, ForeignKeyAction, Iden,
+    ColumnType, DatabaseConnection, DbConn, EntityName, EntityTrait, EnumIter, ForeignKeyAction,
-    IdenStatic, Linked, ModelTrait, PrimaryKeyToColumn, PrimaryKeyTrait, QueryFilter, QueryResult,
+    Iden, IdenStatic, Linked, ModelTrait, PrimaryKeyToColumn, PrimaryKeyTrait, QueryFilter,
-    Related, RelationDef, RelationTrait, Select, Value,
+    QueryResult, Related, RelationDef, RelationTrait, Select, Value,
 };
 
 #[cfg(feature = "macros")]
 pub use crate::{
-    DeriveActiveModel, DeriveActiveModelBehavior, DeriveColumn, DeriveCustomColumn, DeriveEntity,
+    DeriveActiveEnum, DeriveActiveModel, DeriveActiveModelBehavior, DeriveColumn,
-    DeriveEntityModel, DeriveIntoActiveModel, DeriveModel, DerivePrimaryKey, DeriveRelation,
+    DeriveCustomColumn, DeriveEntity, DeriveEntityModel, DeriveIntoActiveModel, DeriveModel,
+    DerivePrimaryKey, DeriveRelation,
 };
 
 #[cfg(feature = "with-json")]

src/error.rs

@@ -11,6 +11,8 @@ pub enum DbErr {
     RecordNotFound(String),
     /// A custom error
     Custom(String),
+    /// Error occurred while parsing value as target type
+    Type(String),
 }
 
 impl std::error::Error for DbErr {}
@@ -23,6 +25,7 @@ impl std::fmt::Display for DbErr {
             Self::Query(s) => write!(f, "Query Error: {}", s),
             Self::RecordNotFound(s) => write!(f, "RecordNotFound Error: {}", s),
             Self::Custom(s) => write!(f, "Custom Error: {}", s),
+            Self::Type(s) => write!(f, "Type Error: {}", s),
         }
     }
 }

src/lib.rs

@@ -293,9 +293,9 @@ pub use schema::*;
 
 #[cfg(feature = "macros")]
 pub use sea_orm_macros::{
-    DeriveActiveModel, DeriveActiveModelBehavior, DeriveColumn, DeriveCustomColumn, DeriveEntity,
+    DeriveActiveEnum, DeriveActiveModel, DeriveActiveModelBehavior, DeriveColumn,
-    DeriveEntityModel, DeriveIntoActiveModel, DeriveModel, DerivePrimaryKey, DeriveRelation,
+    DeriveCustomColumn, DeriveEntity, DeriveEntityModel, DeriveIntoActiveModel, DeriveModel,
-    FromQueryResult,
+    DerivePrimaryKey, DeriveRelation, FromQueryResult,
 };
 
 pub use sea_query;

src/query/insert.rs

@@ -1,9 +1,9 @@
 use crate::{
-    ActiveModelTrait, EntityName, EntityTrait, IntoActiveModel, Iterable, PrimaryKeyTrait,
+    ActiveModelTrait, ColumnTrait, EntityName, EntityTrait, IntoActiveModel, Iterable,
-    QueryTrait,
+    PrimaryKeyTrait, QueryTrait,
 };
 use core::marker::PhantomData;
-use sea_query::{InsertStatement, ValueTuple};
+use sea_query::{Alias, Expr, InsertStatement, ValueTuple};
 
 /// Performs INSERT operations on a ActiveModel
 #[derive(Debug)]
@@ -133,11 +133,18 @@ where
             }
             if av_has_val {
                 columns.push(col);
-                values.push(av.into_value().unwrap());
+                let val = Expr::val(av.into_value().unwrap());
+                let col_def = col.def();
+                let col_type = col_def.get_column_type();
+                let expr = match col_type.get_enum_name() {
+                    Some(enum_name) => val.as_enum(Alias::new(enum_name)),
+                    None => val.into(),
+                };
+                values.push(expr);
             }
         }
         self.query.columns(columns);
-        self.query.values_panic(values);
+        self.query.exprs_panic(values);
         self
     }
 

src/query/select.rs

@@ -2,7 +2,7 @@ use crate::{ColumnTrait, EntityTrait, Iterable, QueryFilter, QueryOrder, QuerySe
 use core::fmt::Debug;
 use core::marker::PhantomData;
 pub use sea_query::JoinType;
-use sea_query::{DynIden, IntoColumnRef, SeaRc, SelectStatement, SimpleExpr};
+use sea_query::{Alias, DynIden, Expr, IntoColumnRef, SeaRc, SelectStatement, SimpleExpr};
 
 /// Defines a structure to perform select operations
 #[derive(Clone, Debug)]
@@ -114,13 +114,24 @@ where
     }
 
     fn prepare_select(mut self) -> Self {
-        self.query.columns(self.column_list());
+        self.query.exprs(self.column_list());
         self
     }
 
-    fn column_list(&self) -> Vec<(DynIden, E::Column)> {
+    fn column_list(&self) -> Vec<SimpleExpr> {
         let table = SeaRc::new(E::default()) as DynIden;
-        E::Column::iter().map(|col| (table.clone(), col)).collect()
+        let text_type = SeaRc::new(Alias::new("text")) as DynIden;
+        E::Column::iter()
+            .map(|col| {
+                let expr = Expr::tbl(table.clone(), col);
+                let col_def = col.def();
+                let col_type = col_def.get_column_type();
+                match col_type.get_enum_name() {
+                    Some(_) => expr.as_enum(text_type.clone()),
+                    None => expr.into(),
+                }
+            })
+            .collect()
     }
 
     fn prepare_from(mut self) -> Self {

src/query/update.rs

@@ -3,7 +3,7 @@ use crate::{
     QueryTrait,
 };
 use core::marker::PhantomData;
-use sea_query::{IntoIden, SimpleExpr, UpdateStatement};
+use sea_query::{Alias, Expr, IntoIden, SimpleExpr, UpdateStatement};
 
 /// Defines a structure to perform UPDATE query operations on a ActiveModel
 #[derive(Clone, Debug)]
@@ -109,7 +109,14 @@ where
             }
             let av = self.model.get(col);
             if av.is_set() {
-                self.query.value(col, av.unwrap());
+                let val = Expr::val(av.into_value().unwrap());
+                let col_def = col.def();
+                let col_type = col_def.get_column_type();
+                let expr = match col_type.get_enum_name() {
+                    Some(enum_name) => val.as_enum(Alias::new(enum_name)),
+                    None => val.into(),
+                };
+                self.query.value_expr(col, expr);
             }
         }
         self

src/schema/entity.rs

@@ -1,20 +1,58 @@
 use crate::{
-    unpack_table_ref, ColumnTrait, EntityTrait, Identity, Iterable, PrimaryKeyToColumn,
+    unpack_table_ref, ColumnTrait, ColumnType, DbBackend, EntityTrait, Identity, Iterable,
-    PrimaryKeyTrait, RelationTrait, Schema,
+    PrimaryKeyToColumn, PrimaryKeyTrait, RelationTrait, Schema,
+};
+use sea_query::{
+    extension::postgres::{Type, TypeCreateStatement},
+    Alias, ColumnDef, ForeignKeyCreateStatement, Iden, Index, TableCreateStatement,
 };
-use sea_query::{ColumnDef, ForeignKeyCreateStatement, Iden, Index, TableCreateStatement};
 
 impl Schema {
-    /// Creates a table from an Entity. See [TableCreateStatement] for more details
+    /// Creates Postgres enums from an Entity. See [TypeCreateStatement] for more details
-    pub fn create_table_from_entity<E>(entity: E) -> TableCreateStatement
+    pub fn create_enum_from_entity<E>(entity: E, db_backend: DbBackend) -> Vec<TypeCreateStatement>
     where
         E: EntityTrait,
     {
-        create_table_from_entity(entity)
+        create_enum_from_entity(entity, db_backend)
+    }
+
+    /// Creates a table from an Entity. See [TableCreateStatement] for more details
+    pub fn create_table_from_entity<E>(entity: E, db_backend: DbBackend) -> TableCreateStatement
+    where
+        E: EntityTrait,
+    {
+        create_table_from_entity(entity, db_backend)
     }
 }
 
-pub(crate) fn create_table_from_entity<E>(entity: E) -> TableCreateStatement
+pub(crate) fn create_enum_from_entity<E>(_: E, db_backend: DbBackend) -> Vec<TypeCreateStatement>
+where
+    E: EntityTrait,
+{
+    if matches!(db_backend, DbBackend::MySql | DbBackend::Sqlite) {
+        return Vec::new();
+    }
+    let mut vec = Vec::new();
+    for col in E::Column::iter() {
+        let col_def = col.def();
+        let col_type = col_def.get_column_type();
+        if !matches!(col_type, ColumnType::Enum(_, _)) {
+            continue;
+        }
+        let (name, values) = match col_type {
+            ColumnType::Enum(s, v) => (s.as_str(), v),
+            _ => unreachable!(),
+        };
+        let stmt = Type::create()
+            .as_enum(Alias::new(name))
+            .values(values.iter().map(|val| Alias::new(val.as_str())))
+            .to_owned();
+        vec.push(stmt);
+    }
+    vec
+}
+
+pub(crate) fn create_table_from_entity<E>(entity: E, db_backend: DbBackend) -> TableCreateStatement
 where
     E: EntityTrait,
 {
@@ -22,7 +60,17 @@ where
 
     for column in E::Column::iter() {
         let orm_column_def = column.def();
-        let types = orm_column_def.col_type.into();
+        let types = match orm_column_def.col_type {
+            ColumnType::Enum(s, variants) => match db_backend {
+                DbBackend::MySql => {
+                    ColumnType::Custom(format!("ENUM('{}')", variants.join("', '")))
+                }
+                DbBackend::Postgres => ColumnType::Custom(s),
+                DbBackend::Sqlite => ColumnType::Text,
+            }
+            .into(),
+            _ => orm_column_def.col_type.into(),
+        };
         let mut column_def = ColumnDef::new_with_type(column, types);
         if !orm_column_def.null {
             column_def.not_null();
@@ -122,13 +170,14 @@ where
 
 #[cfg(test)]
 mod tests {
-    use crate::{sea_query::*, tests_cfg::*, Schema};
+    use crate::{sea_query::*, tests_cfg::*, DbBackend, Schema};
     use pretty_assertions::assert_eq;
 
     #[test]
     fn test_create_table_from_entity() {
         assert_eq!(
-            Schema::create_table_from_entity(CakeFillingPrice).to_string(MysqlQueryBuilder),
+            Schema::create_table_from_entity(CakeFillingPrice, DbBackend::MySql)
+                .to_string(MysqlQueryBuilder),
             Table::create()
                 .table(CakeFillingPrice)
                 .col(

tests/active_enum_tests.rs

@@ -0,0 +1,92 @@
+pub mod common;
+
+pub use common::{features::*, setup::*, TestContext};
+use sea_orm::{entity::prelude::*, entity::*, DatabaseConnection};
+
+#[sea_orm_macros::test]
+#[cfg(any(
+    feature = "sqlx-mysql",
+    feature = "sqlx-sqlite",
+    feature = "sqlx-postgres"
+))]
+async fn main() -> Result<(), DbErr> {
+    let ctx = TestContext::new("active_enum_tests").await;
+    create_tables(&ctx.db).await?;
+    insert_active_enum(&ctx.db).await?;
+    ctx.delete().await;
+
+    Ok(())
+}
+
+pub async fn insert_active_enum(db: &DatabaseConnection) -> Result<(), DbErr> {
+    use active_enum::*;
+
+    let am = ActiveModel {
+        category: Set(None),
+        color: Set(None),
+        tea: Set(None),
+        ..Default::default()
+    }
+    .insert(db)
+    .await?;
+
+    let model = Entity::find().one(db).await?.unwrap();
+    assert_eq!(
+        model,
+        Model {
+            id: 1,
+            category: None,
+            color: None,
+            tea: None,
+        }
+    );
+    assert_eq!(
+        model,
+        Entity::find()
+            .filter(Column::Id.is_not_null())
+            .filter(Column::Category.is_null())
+            .filter(Column::Color.is_null())
+            .filter(Column::Tea.is_null())
+            .one(db)
+            .await?
+            .unwrap()
+    );
+
+    let am = ActiveModel {
+        category: Set(Some(Category::Big)),
+        color: Set(Some(Color::Black)),
+        tea: Set(Some(Tea::EverydayTea)),
+        ..am
+    }
+    .save(db)
+    .await?;
+
+    let model = Entity::find().one(db).await?.unwrap();
+    assert_eq!(
+        model,
+        Model {
+            id: 1,
+            category: Some(Category::Big),
+            color: Some(Color::Black),
+            tea: Some(Tea::EverydayTea),
+        }
+    );
+    assert_eq!(
+        model,
+        Entity::find()
+            .filter(Column::Id.eq(1))
+            .filter(Column::Category.eq(Category::Big))
+            .filter(Column::Color.eq(Color::Black))
+            .filter(Column::Tea.eq(Tea::EverydayTea))
+            .one(db)
+            .await?
+            .unwrap()
+    );
+
+    let res = am.delete(db).await?;
+
+    assert_eq!(res.rows_affected, 1);
+    assert_eq!(Entity::find().one(db).await?, None);
+
+    Ok(())
+}

tests/common/features/active_enum.rs

@@ -0,0 +1,43 @@
+use sea_orm::entity::prelude::*;
+
+#[derive(Clone, Debug, PartialEq, DeriveEntityModel)]
+#[sea_orm(table_name = "active_enum")]
+pub struct Model {
+    #[sea_orm(primary_key)]
+    pub id: i32,
+    pub category: Option<Category>,
+    pub color: Option<Color>,
+    pub tea: Option<Tea>,
+}
+
+#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+pub enum Relation {}
+
+impl ActiveModelBehavior for ActiveModel {}
+
+#[derive(Debug, Clone, PartialEq, EnumIter, DeriveActiveEnum)]
+#[sea_orm(rs_type = "String", db_type = "String(Some(1))")]
+pub enum Category {
+    #[sea_orm(string_value = "B")]
+    Big,
+    #[sea_orm(string_value = "S")]
+    Small,
+}
+
+#[derive(Debug, Clone, PartialEq, EnumIter, DeriveActiveEnum)]
+#[sea_orm(rs_type = "i32", db_type = r#"Integer"#)]
+pub enum Color {
+    #[sea_orm(num_value = 0)]
+    Black,
+    #[sea_orm(num_value = 1)]
+    White,
+}
+
+#[derive(Debug, Clone, PartialEq, EnumIter, DeriveActiveEnum)]
+#[sea_orm(rs_type = "String", db_type = "Enum", enum_name = "tea")]
+pub enum Tea {
+    #[sea_orm(string_value = "EverydayTea")]
+    EverydayTea,
+    #[sea_orm(string_value = "BreakfastTea")]
+    BreakfastTea,
+}

tests/common/features/mod.rs

@@ -1,3 +1,4 @@
+pub mod active_enum;
 pub mod applog;
 pub mod byte_primary_key;
 pub mod metadata;
@@ -5,6 +6,7 @@ pub mod repository;
 pub mod schema;
 pub mod self_join;
 
+pub use active_enum::Entity as ActiveEnum;
 pub use applog::Entity as Applog;
 pub use byte_primary_key::Entity as BytePrimaryKey;
 pub use metadata::Entity as Metadata;

tests/common/features/schema.rs

@@ -1,11 +1,11 @@
 pub use super::super::bakery_chain::*;
 
 use super::*;
-use crate::common::setup::{create_table, create_table_without_asserts};
+use crate::common::setup::{create_enum, create_table, create_table_without_asserts};
 use sea_orm::{
     error::*, sea_query, ConnectionTrait, DatabaseConnection, DbBackend, DbConn, ExecResult,
 };
-use sea_query::{ColumnDef, ForeignKeyCreateStatement};
+use sea_query::{extension::postgres::Type, Alias, ColumnDef, ForeignKeyCreateStatement};
 
 pub async fn create_tables(db: &DatabaseConnection) -> Result<(), DbErr> {
     create_log_table(db).await?;
@@ -13,6 +13,7 @@ pub async fn create_tables(db: &DatabaseConnection) -> Result<(), DbErr> {
     create_repository_table(db).await?;
     create_self_join_table(db).await?;
     create_byte_primary_key_table(db).await?;
+    create_active_enum_table(db).await?;
 
     Ok(())
 }
@@ -123,3 +124,40 @@ pub async fn create_byte_primary_key_table(db: &DbConn) -> Result<ExecResult, Db
 
     create_table_without_asserts(db, &stmt).await
 }
+
+pub async fn create_active_enum_table(db: &DbConn) -> Result<ExecResult, DbErr> {
+    let db_backend = db.get_database_backend();
+    let tea_enum = Alias::new("tea");
+
+    let create_enum_stmts = match db_backend {
+        DbBackend::MySql | DbBackend::Sqlite => Vec::new(),
+        DbBackend::Postgres => vec![Type::create()
+            .as_enum(tea_enum.clone())
+            .values(vec![Alias::new("EverydayTea"), Alias::new("BreakfastTea")])
+            .to_owned()],
+    };
+
+    create_enum(db, &create_enum_stmts, ActiveEnum).await?;
+
+    let mut tea_col = ColumnDef::new(active_enum::Column::Tea);
+    match db_backend {
+        DbBackend::MySql => tea_col.custom(Alias::new("ENUM('EverydayTea', 'BreakfastTea')")),
+        DbBackend::Sqlite => tea_col.text(),
+        DbBackend::Postgres => tea_col.custom(tea_enum),
+    };
+    let create_table_stmt = sea_query::Table::create()
+        .table(active_enum::Entity)
+        .col(
+            ColumnDef::new(active_enum::Column::Id)
+                .integer()
+                .not_null()
+                .auto_increment()
+                .primary_key(),
+        )
+        .col(ColumnDef::new(active_enum::Column::Category).string_len(1))
+        .col(ColumnDef::new(active_enum::Column::Color).integer())
+        .col(&mut tea_col)
+        .to_owned();
+
+    create_table(db, &create_table_stmt, ActiveEnum).await
+}

tests/common/setup/mod.rs

@@ -1,9 +1,12 @@
+use pretty_assertions::assert_eq;
 use sea_orm::{
-    ConnectionTrait, Database, DatabaseBackend, DatabaseConnection, DbBackend, DbConn, DbErr,
+    ColumnTrait, ColumnType, ConnectionTrait, Database, DatabaseBackend, DatabaseConnection,
-    EntityTrait, ExecResult, Schema, Statement,
+    DbBackend, DbConn, DbErr, EntityTrait, ExecResult, Iterable, Schema, Statement,
+};
+use sea_query::{
+    extension::postgres::{Type, TypeCreateStatement},
+    Alias, Table, TableCreateStatement,
 };
-
-use sea_query::{Alias, Table, TableCreateStatement};
 
 pub async fn setup(base_url: &str, db_name: &str) -> DatabaseConnection {
     let db = if cfg!(feature = "sqlx-mysql") {
@@ -74,6 +77,51 @@ pub async fn tear_down(base_url: &str, db_name: &str) {
     };
 }
 
+pub async fn create_enum<E>(
+    db: &DbConn,
+    creates: &[TypeCreateStatement],
+    entity: E,
+) -> Result<(), DbErr>
+where
+    E: EntityTrait,
+{
+    let builder = db.get_database_backend();
+    if builder == DbBackend::Postgres {
+        for col in E::Column::iter() {
+            let col_def = col.def();
+            let col_type = col_def.get_column_type();
+            if !matches!(col_type, ColumnType::Enum(_, _)) {
+                continue;
+            }
+            let name = match col_type {
+                ColumnType::Enum(s, _) => s.as_str(),
+                _ => unreachable!(),
+            };
+            let drop_type_stmt = Type::drop()
+                .name(Alias::new(name))
+                .if_exists()
+                .cascade()
+                .to_owned();
+            let stmt = builder.build(&drop_type_stmt);
+            db.execute(stmt).await?;
+        }
+    }
+
+    let expect_stmts: Vec<Statement> = creates.iter().map(|stmt| builder.build(stmt)).collect();
+    let create_from_entity_stmts: Vec<Statement> = Schema::create_enum_from_entity(entity, builder)
+        .iter()
+        .map(|stmt| builder.build(stmt))
+        .collect();
+
+    assert_eq!(expect_stmts, create_from_entity_stmts);
+
+    for stmt in expect_stmts {
+        db.execute(stmt).await.map(|_| ())?;
+    }
+
+    Ok(())
+}
+
 pub async fn create_table<E>(
     db: &DbConn,
     create: &TableCreateStatement,
@@ -84,7 +132,7 @@ where
 {
     let builder = db.get_database_backend();
     assert_eq!(
-        builder.build(&Schema::create_table_from_entity(entity)),
+        builder.build(&Schema::create_table_from_entity(entity, builder)),
         builder.build(create)
     );