diff --git a/Cargo.toml b/Cargo.toml
index b8da7967..dda0f88c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,8 +23,9 @@ name = "sea_orm"
 path = "src/lib.rs"
 
 [dependencies]
-async-trait = "^0.1"
+async-stream = { version = "^0.3" }
 futures = { version = "^0.3" }
+futures-util = { version = "^0.3" }
 sea-query = { path = "../sea-query", version = "^0.12" }
 sea-orm-macros = { path = "sea-orm-macros", optional = true }
 # sea-schema = { path = "../sea-schema" }
@@ -32,15 +33,14 @@ serde = { version = "^1.0", features = [ "derive" ] }
 sqlx = { version = "^0.5", optional = true }
 strum = { version = "^0.20", features = [ "derive" ] }
 serde_json = { version = "^1", optional = true }
-async-stream = { version = "^0.3" }
-futures-util = { version = "^0.3" }
 
 [features]
 debug-print = []
-default = [ "macros", "sqlx-mysql", "runtime-async-std-native-tls", "with-json" ]
+default = [ "macros", "with-json", "mock", "sqlx-mysql", "runtime-async-std-native-tls" ]
 macros = [ "sea-orm-macros" ]
-with-json = [ "serde_json" ]
-sqlx-dep = [ "sqlx" ]
+mock = []
+with-json = [ "serde_json", "sea-query/with-json" ]
+sqlx-dep = [ "sqlx", "sqlx/json" ]
 sqlx-mysql = [ "sqlx-dep", "sea-query/sqlx-mysql", "sqlx/mysql" ]
 sqlx-postgres = [ "sqlx-dep", "sea-query/sqlx-postgres", "sqlx/postgres" ]
 runtime-actix-native-tls = [ "sqlx/runtime-actix-native-tls" ]
diff --git a/examples/sqlx-mysql/Cargo.toml b/examples/sqlx-mysql/Cargo.toml
index 44f398b1..27c52348 100644
--- a/examples/sqlx-mysql/Cargo.toml
+++ b/examples/sqlx-mysql/Cargo.toml
@@ -6,7 +6,7 @@ publish = false
 
 [dependencies]
 async-std = { version = "^1.9", features = [ "attributes" ] }
-sea-orm = { path = "../../", features = [ "sqlx-mysql", "runtime-async-std-native-tls", "debug-print" ] }
+sea-orm = { path = "../../", features = [ "sqlx-mysql", "runtime-async-std-native-tls", "debug-print", "with-json", "macros" ], default-features = false }
 # sea-query = { path = "../../../sea-query" }
 strum = { version = "^0.20", features = [ "derive" ] }
 serde_json = { version = "^1" }
diff --git a/src/database/connection.rs b/src/database/connection.rs
new file mode 100644
index 00000000..85ed546c
--- /dev/null
+++ b/src/database/connection.rs
@@ -0,0 +1,137 @@
+use crate::{ExecErr, ExecResult, QueryErr, QueryResult, Statement};
+use sea_query::{
+    DeleteStatement, InsertStatement, MysqlQueryBuilder, PostgresQueryBuilder, SelectStatement,
+    UpdateStatement,
+};
+use std::{error::Error, fmt};
+
+pub enum DatabaseConnection {
+    #[cfg(feature = "sqlx-mysql")]
+    SqlxMySqlPoolConnection(crate::SqlxMySqlPoolConnection),
+    #[cfg(feature = "mock")]
+    MockDatabaseConnection(crate::MockDatabaseConnection),
+    Disconnected,
+}
+
+pub enum QueryBuilderBackend {
+    MySql,
+    Postgres,
+}
+
+#[derive(Debug)]
+pub struct ConnectionErr;
+
+impl Error for ConnectionErr {}
+
+impl fmt::Display for ConnectionErr {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
+impl Default for DatabaseConnection {
+    fn default() -> Self {
+        Self::Disconnected
+    }
+}
+
+impl std::fmt::Debug for DatabaseConnection {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                #[cfg(feature = "sqlx-mysql")]
+                Self::SqlxMySqlPoolConnection(_) => "SqlxMySqlPoolConnection",
+                #[cfg(feature = "mock")]
+                Self::MockDatabaseConnection(_) => "MockDatabaseConnection",
+                Self::Disconnected => "Disconnected",
+            }
+        )
+    }
+}
+
+impl DatabaseConnection {
+    pub fn get_query_builder_backend(&self) -> QueryBuilderBackend {
+        match self {
+            #[cfg(feature = "sqlx-mysql")]
+            DatabaseConnection::SqlxMySqlPoolConnection(_) => QueryBuilderBackend::MySql,
+            #[cfg(feature = "mock")]
+            DatabaseConnection::MockDatabaseConnection(_) => QueryBuilderBackend::Postgres,
+            DatabaseConnection::Disconnected => panic!("Disconnected"),
+        }
+    }
+
+    pub async fn execute(
+        &self,
+        stmt: Statement,
+    ) -> Result<ExecResult, ExecErr> {
+        match self {
+            #[cfg(feature = "sqlx-mysql")]
+            DatabaseConnection::SqlxMySqlPoolConnection(conn) => conn.execute(stmt).await,
+            #[cfg(feature = "mock")]
+            DatabaseConnection::MockDatabaseConnection(conn) => conn.execute(stmt).await,
+            DatabaseConnection::Disconnected => panic!("Disconnected"),
+        }
+    }
+
+    pub async fn query_one(
+        &self,
+        stmt: Statement,
+    ) -> Result<Option<QueryResult>, QueryErr> {
+        match self {
+            #[cfg(feature = "sqlx-mysql")]
+            DatabaseConnection::SqlxMySqlPoolConnection(conn) => conn.query_one(stmt).await,
+            #[cfg(feature = "mock")]
+            DatabaseConnection::MockDatabaseConnection(conn) => conn.query_one(stmt).await,
+            DatabaseConnection::Disconnected => panic!("Disconnected"),
+        }
+    }
+
+    pub async fn query_all(
+        &self,
+        stmt: Statement,
+    ) -> Result<Vec<QueryResult>, QueryErr> {
+        match self {
+            #[cfg(feature = "sqlx-mysql")]
+            DatabaseConnection::SqlxMySqlPoolConnection(conn) => conn.query_all(stmt).await,
+            #[cfg(feature = "mock")]
+            DatabaseConnection::MockDatabaseConnection(conn) => conn.query_all(stmt).await,
+            DatabaseConnection::Disconnected => panic!("Disconnected"),
+        }
+    }
+}
+
+impl QueryBuilderBackend {
+    pub fn build_select_statement(&self, statement: &SelectStatement) -> Statement {
+        match self {
+            Self::MySql => statement.build(MysqlQueryBuilder),
+            Self::Postgres => statement.build(PostgresQueryBuilder),
+        }
+        .into()
+    }
+
+    pub fn build_insert_statement(&self, statement: &InsertStatement) -> Statement {
+        match self {
+            Self::MySql => statement.build(MysqlQueryBuilder),
+            Self::Postgres => statement.build(PostgresQueryBuilder),
+        }
+        .into()
+    }
+
+    pub fn build_update_statement(&self, statement: &UpdateStatement) -> Statement {
+        match self {
+            Self::MySql => statement.build(MysqlQueryBuilder),
+            Self::Postgres => statement.build(PostgresQueryBuilder),
+        }
+        .into()
+    }
+
+    pub fn build_delete_statement(&self, statement: &DeleteStatement) -> Statement {
+        match self {
+            Self::MySql => statement.build(MysqlQueryBuilder),
+            Self::Postgres => statement.build(PostgresQueryBuilder),
+        }
+        .into()
+    }
+}
diff --git a/src/database/mock.rs b/src/database/mock.rs
new file mode 100644
index 00000000..8336d093
--- /dev/null
+++ b/src/database/mock.rs
@@ -0,0 +1,66 @@
+use crate::{ExecErr, ExecResult, MockDatabaseTrait, QueryErr, QueryResult, Statement, TypeErr};
+use sea_query::{Value, ValueType};
+use std::collections::BTreeMap;
+
+#[derive(Debug, Default)]
+pub struct MockDatabase {
+    transaction_log: Vec<Statement>,
+    exec_results: Vec<ExecResult>,
+    query_results: Vec<Vec<QueryResult>>,
+}
+
+#[derive(Clone, Debug)]
+pub struct MockExecResult {
+    pub last_insert_id: u64,
+    pub rows_affected: u64,
+}
+
+#[derive(Clone, Debug)]
+pub struct MockRow {
+    values: BTreeMap<String, Value>,
+}
+
+impl MockDatabase {
+    pub fn new() -> Self {
+        Default::default()
+    }
+}
+
+impl MockDatabaseTrait for MockDatabase {
+    fn execute(&mut self, counter: usize, statement: Statement) -> Result<ExecResult, ExecErr> {
+        self.transaction_log.push(statement);
+        if counter < self.exec_results.len() {
+            Err(ExecErr)
+            // Ok(self.exec_results[counter].clone())
+        } else {
+            Err(ExecErr)
+        }
+    }
+
+    fn query(
+        &mut self,
+        counter: usize,
+        statement: Statement,
+    ) -> Result<Vec<QueryResult>, QueryErr> {
+        self.transaction_log.push(statement);
+        if counter < self.query_results.len() {
+            Err(QueryErr)
+            // Ok(self.query_results[counter].clone())
+        } else {
+            Err(QueryErr)
+        }
+    }
+}
+
+impl MockRow {
+    pub fn try_get<T>(&self, col: &str) -> Result<T, TypeErr>
+    where
+        T: ValueType,
+    {
+        Ok(self.values.get(col).unwrap().clone().unwrap())
+    }
+
+    pub fn into_column_value_tuples(self) -> impl Iterator<Item = (String, Value)> {
+        self.values.into_iter()
+    }
+}
diff --git a/src/database/mod.rs b/src/database/mod.rs
index 72d694b3..894278d8 100644
--- a/src/database/mod.rs
+++ b/src/database/mod.rs
@@ -1,63 +1,38 @@
+mod connection;
+#[cfg(feature = "mock")]
+mod mock;
 mod statement;
 
+pub use connection::*;
+#[cfg(feature = "mock")]
+pub use mock::*;
 pub use statement::*;
 
-use crate::{Connection, ConnectionErr, Connector, SqlxMySqlConnector, SqlxMySqlPoolConnection};
-use sea_query::{GenericBuilder, MySqlQueryBuilder};
-
 #[derive(Debug, Default)]
 pub struct Database {
     connection: DatabaseConnection,
 }
 
-pub enum DatabaseConnection {
-    SqlxMySqlPoolConnection(SqlxMySqlPoolConnection),
-    Disconnected,
-}
-
-// DatabaseConnection //
-
-impl Default for DatabaseConnection {
-    fn default() -> Self {
-        Self::Disconnected
-    }
-}
-
-impl std::fmt::Debug for DatabaseConnection {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(
-            f,
-            "{}",
-            match self {
-                Self::SqlxMySqlPoolConnection(_) => "SqlxMySqlPoolConnection",
-                Self::Disconnected => "Disconnected",
-            }
-        )
-    }
-}
-
-// Database //
-
 impl Database {
     pub async fn connect(&mut self, string: &str) -> Result<(), ConnectionErr> {
-        if SqlxMySqlConnector::accepts(string) {
-            self.connection = SqlxMySqlConnector::connect(string).await?;
+        #[cfg(feature = "sqlx-mysql")]
+        if crate::SqlxMySqlConnector::accepts(string) {
+            self.connection = crate::SqlxMySqlConnector::connect(string).await?;
+            return Ok(());
+        }
+        #[cfg(feature = "mock")]
+        if crate::MockDatabaseConnector::accepts(string) {
+            self.connection = crate::MockDatabaseConnector::connect(string).await?;
             return Ok(());
         }
         Err(ConnectionErr)
     }
 
-    pub fn get_connection(&self) -> impl Connection + '_ {
-        match &self.connection {
-            DatabaseConnection::SqlxMySqlPoolConnection(conn) => conn,
-            DatabaseConnection::Disconnected => panic!("Disconnected"),
-        }
+    pub fn get_connection(&self) -> &DatabaseConnection {
+        &self.connection
     }
 
-    pub fn get_query_builder_backend(&self) -> impl GenericBuilder {
-        match &self.connection {
-            DatabaseConnection::SqlxMySqlPoolConnection(_) => MySqlQueryBuilder::default(),
-            DatabaseConnection::Disconnected => panic!("Disconnected"),
-        }
+    pub fn get_query_builder_backend(&self) -> QueryBuilderBackend {
+        self.connection.get_query_builder_backend()
     }
 }
diff --git a/src/database/statement.rs b/src/database/statement.rs
index c2f3c2f4..61604b38 100644
--- a/src/database/statement.rs
+++ b/src/database/statement.rs
@@ -1,6 +1,7 @@
 use sea_query::{inject_parameters, MySqlQueryBuilder, Values};
 use std::fmt;
 
+#[derive(Debug, Clone)]
 pub struct Statement {
     pub sql: String,
     pub values: Option<Values>,
diff --git a/src/driver/mock.rs b/src/driver/mock.rs
new file mode 100644
index 00000000..9189e306
--- /dev/null
+++ b/src/driver/mock.rs
@@ -0,0 +1,76 @@
+use crate::{
+    debug_print, ConnectionErr, DatabaseConnection, ExecErr, ExecResult, MockDatabase, QueryErr,
+    QueryResult, Statement,
+};
+use std::sync::{
+    atomic::{AtomicUsize, Ordering},
+    Mutex,
+};
+
+pub struct MockDatabaseConnector;
+
+pub struct MockDatabaseConnection {
+    counter: AtomicUsize,
+    mocker: Mutex<Box<dyn MockDatabaseTrait>>,
+}
+
+pub trait MockDatabaseTrait: Send {
+    fn execute(&mut self, counter: usize, stmt: Statement) -> Result<ExecResult, ExecErr>;
+
+    fn query(&mut self, counter: usize, stmt: Statement) -> Result<Vec<QueryResult>, QueryErr>;
+}
+
+impl MockDatabaseConnector {
+    pub fn accepts(_string: &str) -> bool {
+        true
+    }
+
+    pub async fn connect(_string: &str) -> Result<DatabaseConnection, ConnectionErr> {
+        Ok(DatabaseConnection::MockDatabaseConnection(
+            MockDatabaseConnection::new(MockDatabase::new()),
+        ))
+    }
+}
+
+impl MockDatabaseConnection {
+    pub fn new<M: 'static>(m: M) -> Self
+    where
+        M: MockDatabaseTrait,
+    {
+        Self {
+            counter: AtomicUsize::new(0),
+            mocker: Mutex::new(Box::new(m)),
+        }
+    }
+}
+
+impl MockDatabaseConnection {
+    pub async fn execute(&self, statement: Statement) -> Result<ExecResult, ExecErr> {
+        debug_print!("{}", statement);
+        self.counter.fetch_add(1, Ordering::SeqCst);
+        self.mocker
+            .lock()
+            .unwrap()
+            .execute(self.counter.load(Ordering::SeqCst), statement)
+    }
+
+    pub async fn query_one(&self, statement: Statement) -> Result<Option<QueryResult>, QueryErr> {
+        debug_print!("{}", statement);
+        self.counter.fetch_add(1, Ordering::SeqCst);
+        let result = self
+            .mocker
+            .lock()
+            .unwrap()
+            .query(self.counter.load(Ordering::SeqCst), statement)?;
+        Ok(result.into_iter().next())
+    }
+
+    pub async fn query_all(&self, statement: Statement) -> Result<Vec<QueryResult>, QueryErr> {
+        debug_print!("{}", statement);
+        self.counter.fetch_add(1, Ordering::SeqCst);
+        self.mocker
+            .lock()
+            .unwrap()
+            .query(self.counter.load(Ordering::SeqCst), statement)
+    }
+}
diff --git a/src/driver/mod.rs b/src/driver/mod.rs
index f49ce557..963a1597 100644
--- a/src/driver/mod.rs
+++ b/src/driver/mod.rs
@@ -1,3 +1,9 @@
+#[cfg(feature = "mock")]
+mod mock;
+#[cfg(feature = "sqlx-mysql")]
 mod sqlx_mysql;
 
+#[cfg(feature = "mock")]
+pub use mock::*;
+#[cfg(feature = "sqlx-mysql")]
 pub use sqlx_mysql::*;
diff --git a/src/driver/sqlx_mysql.rs b/src/driver/sqlx_mysql.rs
index 80d5a7b9..a53e6142 100644
--- a/src/driver/sqlx_mysql.rs
+++ b/src/driver/sqlx_mysql.rs
@@ -1,4 +1,3 @@
-use async_trait::async_trait;
 use sqlx::{
     mysql::{MySqlArguments, MySqlQueryResult, MySqlRow},
     MySql, MySqlPool,
@@ -7,7 +6,7 @@ use sqlx::{
 sea_query::sea_query_driver_mysql!();
 use sea_query_driver_mysql::bind_query;
 
-use crate::{debug_print, executor::*, DatabaseConnection, Statement};
+use crate::{debug_print, executor::*, DatabaseConnection, Statement, ConnectionErr};
 
 pub struct SqlxMySqlConnector;
 
@@ -15,13 +14,12 @@ pub struct SqlxMySqlPoolConnection {
     pool: MySqlPool,
 }
 
-#[async_trait]
-impl Connector for SqlxMySqlConnector {
-    fn accepts(string: &str) -> bool {
+impl SqlxMySqlConnector {
+    pub fn accepts(string: &str) -> bool {
         string.starts_with("mysql://")
     }
 
-    async fn connect(string: &str) -> Result<DatabaseConnection, ConnectionErr> {
+    pub async fn connect(string: &str) -> Result<DatabaseConnection, ConnectionErr> {
         if let Ok(pool) = MySqlPool::connect(string).await {
             Ok(DatabaseConnection::SqlxMySqlPoolConnection(
                 SqlxMySqlPoolConnection { pool },
@@ -38,9 +36,8 @@ impl SqlxMySqlConnector {
     }
 }
 
-#[async_trait]
-impl Connection for &SqlxMySqlPoolConnection {
-    async fn execute(&self, stmt: Statement) -> Result<ExecResult, ExecErr> {
+impl SqlxMySqlPoolConnection {
+    pub async fn execute(&self, stmt: Statement) -> Result<ExecResult, ExecErr> {
         debug_print!("{}", stmt);
 
         let query = sqlx_query(&stmt);
@@ -52,7 +49,7 @@ impl Connection for &SqlxMySqlPoolConnection {
         Err(ExecErr)
     }
 
-    async fn query_one(&self, stmt: Statement) -> Result<Option<QueryResult>, QueryErr> {
+    pub async fn query_one(&self, stmt: Statement) -> Result<Option<QueryResult>, QueryErr> {
         debug_print!("{}", stmt);
 
         let query = sqlx_query(&stmt);
@@ -67,7 +64,7 @@ impl Connection for &SqlxMySqlPoolConnection {
         }
     }
 
-    async fn query_all(&self, stmt: Statement) -> Result<Vec<QueryResult>, QueryErr> {
+    pub async fn query_all(&self, stmt: Statement) -> Result<Vec<QueryResult>, QueryErr> {
         debug_print!("{}", stmt);
 
         let query = sqlx_query(&stmt);
@@ -96,6 +93,18 @@ impl From<MySqlQueryResult> for ExecResult {
     }
 }
 
+impl From<sqlx::Error> for TypeErr {
+    fn from(_: sqlx::Error) -> TypeErr {
+        TypeErr
+    }
+}
+
+impl From<sqlx::Error> for ExecErr {
+    fn from(_: sqlx::Error) -> ExecErr {
+        ExecErr
+    }
+}
+
 fn sqlx_query(stmt: &Statement) -> sqlx::query::Query<'_, MySql, MySqlArguments> {
     let mut query = sqlx::query(&stmt.sql);
     if let Some(values) = &stmt.values {
diff --git a/src/executor/connector.rs b/src/executor/connector.rs
deleted file mode 100644
index 5a6daf4d..00000000
--- a/src/executor/connector.rs
+++ /dev/null
@@ -1,33 +0,0 @@
-use super::{ExecErr, ExecResult, QueryErr, QueryResult};
-use crate::{DatabaseConnection, Statement};
-use async_trait::async_trait;
-use std::{error::Error, fmt};
-
-#[async_trait]
-pub trait Connector {
-    fn accepts(string: &str) -> bool;
-
-    async fn connect(string: &str) -> Result<DatabaseConnection, ConnectionErr>;
-}
-
-#[async_trait]
-pub trait Connection {
-    async fn execute(&self, stmt: Statement) -> Result<ExecResult, ExecErr>;
-
-    async fn query_one(&self, stmt: Statement) -> Result<Option<QueryResult>, QueryErr>;
-
-    async fn query_all(&self, stmt: Statement) -> Result<Vec<QueryResult>, QueryErr>;
-}
-
-#[derive(Debug)]
-pub struct ConnectionErr;
-
-// ConnectionErr //
-
-impl Error for ConnectionErr {}
-
-impl fmt::Display for ConnectionErr {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{:?}", self)
-    }
-}
diff --git a/src/executor/delete.rs b/src/executor/delete.rs
index 2a6e8903..388f4a8c 100644
--- a/src/executor/delete.rs
+++ b/src/executor/delete.rs
@@ -1,7 +1,8 @@
 use crate::{
-    ActiveModelTrait, Connection, Database, DeleteMany, DeleteOne, EntityTrait, ExecErr, Statement,
+    ActiveModelTrait, Database, DeleteMany, DeleteOne, EntityTrait, ExecErr, QueryBuilderBackend,
+    Statement,
 };
-use sea_query::{DeleteStatement, QueryBuilder};
+use sea_query::DeleteStatement;
 use std::future::Future;
 
 #[derive(Clone, Debug)]
@@ -45,11 +46,8 @@ impl Deleter {
         Self { query }
     }
 
-    pub fn build<B>(&self, builder: B) -> Statement
-    where
-        B: QueryBuilder,
-    {
-        self.query.build(builder).into()
+    pub fn build(&self, builder: QueryBuilderBackend) -> Statement {
+        builder.build_delete_statement(&self.query)
     }
 
     pub fn exec(self, db: &Database) -> impl Future<Output = Result<DeleteResult, ExecErr>> + '_ {
diff --git a/src/executor/execute.rs b/src/executor/execute.rs
index b5b51e09..b735cce2 100644
--- a/src/executor/execute.rs
+++ b/src/executor/execute.rs
@@ -1,4 +1,3 @@
-use sqlx::mysql::MySqlQueryResult;
 use std::{error::Error, fmt};
 
 #[derive(Debug)]
@@ -8,7 +7,10 @@ pub struct ExecResult {
 
 #[derive(Debug)]
 pub(crate) enum ExecResultHolder {
-    SqlxMySql(MySqlQueryResult),
+    #[cfg(feature = "sqlx-mysql")]
+    SqlxMySql(sqlx::mysql::MySqlQueryResult),
+    #[cfg(feature = "mock")]
+    Mock(crate::MockExecResult),
 }
 
 #[derive(Debug)]
@@ -19,13 +21,19 @@ pub struct ExecErr;
 impl ExecResult {
     pub fn last_insert_id(&self) -> u64 {
         match &self.result {
+            #[cfg(feature = "sqlx-mysql")]
             ExecResultHolder::SqlxMySql(result) => result.last_insert_id(),
+            #[cfg(feature = "mock")]
+            ExecResultHolder::Mock(result) => result.last_insert_id,
         }
     }
 
     pub fn rows_affected(&self) -> u64 {
         match &self.result {
+            #[cfg(feature = "sqlx-mysql")]
             ExecResultHolder::SqlxMySql(result) => result.rows_affected(),
+            #[cfg(feature = "mock")]
+            ExecResultHolder::Mock(result) => result.rows_affected,
         }
     }
 }
@@ -39,9 +47,3 @@ impl fmt::Display for ExecErr {
         write!(f, "{:?}", self)
     }
 }
-
-impl From<sqlx::Error> for ExecErr {
-    fn from(_: sqlx::Error) -> ExecErr {
-        ExecErr
-    }
-}
diff --git a/src/executor/insert.rs b/src/executor/insert.rs
index 0488be9c..79a65970 100644
--- a/src/executor/insert.rs
+++ b/src/executor/insert.rs
@@ -1,5 +1,7 @@
-use crate::{ActiveModelTrait, Connection, Database, ExecErr, Insert, QueryTrait, Statement};
-use sea_query::{InsertStatement, QueryBuilder};
+use crate::{
+    ActiveModelTrait, Database, ExecErr, Insert, QueryBuilderBackend, QueryTrait, Statement,
+};
+use sea_query::InsertStatement;
 use std::future::Future;
 
 #[derive(Clone, Debug)]
@@ -27,11 +29,8 @@ impl Inserter {
         Self { query }
     }
 
-    pub fn build<B>(&self, builder: B) -> Statement
-    where
-        B: QueryBuilder,
-    {
-        self.query.build(builder).into()
+    pub fn build(&self, builder: QueryBuilderBackend) -> Statement {
+        builder.build_insert_statement(&self.query)
     }
 
     pub fn exec(self, db: &Database) -> impl Future<Output = Result<InsertResult, ExecErr>> + '_ {
diff --git a/src/executor/mod.rs b/src/executor/mod.rs
index 7f37bcf1..4be8227e 100644
--- a/src/executor/mod.rs
+++ b/src/executor/mod.rs
@@ -1,4 +1,3 @@
-mod connector;
 mod delete;
 mod execute;
 mod insert;
@@ -7,7 +6,6 @@ mod query;
 mod select;
 mod update;
 
-pub use connector::*;
 pub use delete::*;
 pub use execute::*;
 pub use insert::*;
diff --git a/src/executor/paginator.rs b/src/executor/paginator.rs
index abc2093d..3196248e 100644
--- a/src/executor/paginator.rs
+++ b/src/executor/paginator.rs
@@ -1,4 +1,4 @@
-use crate::{Connection, Database, QueryErr, SelectorTrait};
+use crate::{Database, QueryErr, SelectorTrait};
 use async_stream::stream;
 use futures::Stream;
 use sea_query::{Alias, Expr, SelectStatement};
@@ -31,7 +31,7 @@ where
             .offset((self.page_size * page) as u64)
             .to_owned();
         let builder = self.db.get_query_builder_backend();
-        let stmt = query.build(builder).into();
+        let stmt = builder.build_select_statement(&query);
         let rows = self.db.get_connection().query_all(stmt).await?;
         let mut buffer = Vec::with_capacity(rows.len());
         for row in rows.into_iter() {
@@ -49,14 +49,14 @@ where
     /// Get the total number of pages
     pub async fn num_pages(&self) -> Result<usize, QueryErr> {
         let builder = self.db.get_query_builder_backend();
-        let stmt = SelectStatement::new()
-            .expr(Expr::cust("COUNT(*) AS num_rows"))
-            .from_subquery(
-                self.query.clone().reset_limit().reset_offset().to_owned(),
-                Alias::new("sub_query"),
-            )
-            .build(builder)
-            .into();
+        let stmt = builder.build_select_statement(
+            SelectStatement::new()
+                .expr(Expr::cust("COUNT(*) AS num_rows"))
+                .from_subquery(
+                    self.query.clone().reset_limit().reset_offset().to_owned(),
+                    Alias::new("sub_query"),
+                ),
+        );
         let result = match self.db.get_connection().query_one(stmt).await? {
             Some(res) => res,
             None => return Ok(0),
diff --git a/src/executor/query.rs b/src/executor/query.rs
index d6c71ad6..3f73cce4 100644
--- a/src/executor/query.rs
+++ b/src/executor/query.rs
@@ -1,4 +1,3 @@
-use sqlx::mysql::MySqlRow;
 use std::{error::Error, fmt};
 
 #[derive(Debug)]
@@ -8,7 +7,10 @@ pub struct QueryResult {
 
 #[derive(Debug)]
 pub(crate) enum QueryResultRow {
-    SqlxMySql(MySqlRow),
+    #[cfg(feature = "sqlx-mysql")]
+    SqlxMySql(sqlx::mysql::MySqlRow),
+    #[cfg(feature = "mock")]
+    Mock(crate::MockRow),
 }
 
 #[derive(Debug)]
@@ -60,12 +62,6 @@ impl fmt::Display for TypeErr {
     }
 }
 
-impl From<sqlx::Error> for TypeErr {
-    fn from(_: sqlx::Error) -> TypeErr {
-        TypeErr
-    }
-}
-
 // TryGetable //
 
 macro_rules! try_getable {
@@ -74,10 +70,13 @@ macro_rules! try_getable {
             fn try_get(res: &QueryResult, pre: &str, col: &str) -> Result<Self, TypeErr> {
                 let column = format!("{}{}", pre, col);
                 match &res.row {
+                    #[cfg(feature = "sqlx-mysql")]
                     QueryResultRow::SqlxMySql(row) => {
                         use sqlx::Row;
                         Ok(row.try_get(column.as_str())?)
                     }
+                    #[cfg(feature = "mock")]
+                    QueryResultRow::Mock(row) => Ok(row.try_get(column.as_str())?),
                 }
             }
         }
@@ -86,6 +85,7 @@ macro_rules! try_getable {
             fn try_get(res: &QueryResult, pre: &str, col: &str) -> Result<Self, TypeErr> {
                 let column = format!("{}{}", pre, col);
                 match &res.row {
+                    #[cfg(feature = "sqlx-mysql")]
                     QueryResultRow::SqlxMySql(row) => {
                         use sqlx::Row;
                         match row.try_get(column.as_str()) {
@@ -93,6 +93,11 @@ macro_rules! try_getable {
                             Err(_) => Ok(None),
                         }
                     }
+                    #[cfg(feature = "mock")]
+                    QueryResultRow::Mock(row) => match row.try_get(column.as_str()) {
+                        Ok(v) => Ok(Some(v)),
+                        Err(_) => Ok(None),
+                    },
                 }
             }
         }
diff --git a/src/executor/select.rs b/src/executor/select.rs
index b137267d..d89a92b6 100644
--- a/src/executor/select.rs
+++ b/src/executor/select.rs
@@ -1,8 +1,8 @@
 use crate::{
-    query::combine, Connection, Database, EntityTrait, FromQueryResult, JsonValue, Paginator,
-    QueryErr, QueryResult, Select, SelectTwo, Statement, TypeErr,
+    query::combine, Database, EntityTrait, FromQueryResult, JsonValue, Paginator,
+    QueryBuilderBackend, QueryErr, QueryResult, Select, SelectTwo, Statement, TypeErr,
 };
-use sea_query::{QueryBuilder, SelectStatement};
+use sea_query::SelectStatement;
 use std::marker::PhantomData;
 
 #[derive(Clone, Debug)]
@@ -134,11 +134,8 @@ impl<S> Selector<S>
 where
     S: SelectorTrait,
 {
-    pub fn build<B>(&self, builder: B) -> Statement
-    where
-        B: QueryBuilder,
-    {
-        self.query.build(builder).into()
+    pub fn build(&self, builder: QueryBuilderBackend) -> Statement {
+        builder.build_select_statement(&self.query)
     }
 
     pub async fn one(mut self, db: &Database) -> Result<Option<S::Item>, QueryErr> {
diff --git a/src/executor/update.rs b/src/executor/update.rs
index 2912c751..28773534 100644
--- a/src/executor/update.rs
+++ b/src/executor/update.rs
@@ -1,7 +1,8 @@
 use crate::{
-    ActiveModelTrait, Connection, Database, EntityTrait, ExecErr, Statement, UpdateMany, UpdateOne,
+    ActiveModelTrait, Database, EntityTrait, ExecErr, QueryBuilderBackend, Statement, UpdateMany,
+    UpdateOne,
 };
-use sea_query::{QueryBuilder, UpdateStatement};
+use sea_query::UpdateStatement;
 use std::future::Future;
 
 #[derive(Clone, Debug)]
@@ -42,11 +43,8 @@ impl Updater {
         Self { query }
     }
 
-    pub fn build<B>(&self, builder: B) -> Statement
-    where
-        B: QueryBuilder,
-    {
-        self.query.build(builder).into()
+    pub fn build(&self, builder: QueryBuilderBackend) -> Statement {
+        builder.build_update_statement(&self.query)
     }
 
     pub fn exec(self, db: &Database) -> impl Future<Output = Result<UpdateResult, ExecErr>> + '_ {
diff --git a/src/query/json.rs b/src/query/json.rs
index d8a4c963..4cc07157 100644
--- a/src/query/json.rs
+++ b/src/query/json.rs
@@ -1,11 +1,13 @@
 use crate::{FromQueryResult, QueryResult, QueryResultRow, TypeErr};
+use serde_json::Map;
 pub use serde_json::Value as JsonValue;
-use serde_json::{json, Map};
 
 impl FromQueryResult for JsonValue {
     fn from_query_result(res: &QueryResult, pre: &str) -> Result<Self, TypeErr> {
         match &res.row {
+            #[cfg(feature = "sqlx-mysql")]
             QueryResultRow::SqlxMySql(row) => {
+                use serde_json::json;
                 use sqlx::{Column, MySql, Row, Type};
                 let mut map = Map::new();
                 for column in row.columns() {
@@ -41,6 +43,19 @@ impl FromQueryResult for JsonValue {
                 }
                 Ok(JsonValue::Object(map))
             }
+            #[cfg(feature = "mock")]
+            QueryResultRow::Mock(row) => {
+                let mut map = Map::new();
+                for (column, value) in row.clone().into_column_value_tuples() {
+                    let col = if !column.starts_with(pre) {
+                        continue;
+                    } else {
+                        column.replacen(pre, "", 1)
+                    };
+                    map.insert(col, sea_query::sea_value_to_json_value(&value));
+                }
+                Ok(JsonValue::Object(map))
+            }
         }
     }
 }
diff --git a/src/query/result.rs b/src/query/result.rs
deleted file mode 100644
index 713fbb87..00000000
--- a/src/query/result.rs
+++ /dev/null
@@ -1,94 +0,0 @@
-use sqlx::mysql::MySqlRow;
-use std::{error::Error, fmt};
-
-#[derive(Debug)]
-pub struct QueryResult {
-    pub(crate) row: QueryResultRow,
-}
-
-#[derive(Debug)]
-pub(crate) enum QueryResultRow {
-    SqlxMySql(MySqlRow),
-}
-
-#[derive(Debug)]
-pub struct TypeErr;
-
-pub trait TryGetable {
-    fn try_get(res: &QueryResult, pre: &str, col: &str) -> Result<Self, TypeErr>
-    where
-        Self: Sized;
-}
-
-// TryGetable //
-
-macro_rules! try_getable {
-    ( $type: ty ) => {
-        impl TryGetable for $type {
-            fn try_get(res: &QueryResult, pre: &str, col: &str) -> Result<Self, TypeErr> {
-                let column = format!("{}{}", pre, col);
-                match &res.row {
-                    QueryResultRow::SqlxMySql(row) => {
-                        use sqlx::Row;
-                        Ok(row.try_get(column.as_str())?)
-                    }
-                }
-            }
-        }
-
-        impl TryGetable for Option<$type> {
-            fn try_get(res: &QueryResult, pre: &str, col: &str) -> Result<Self, TypeErr> {
-                let column = format!("{}{}", pre, col);
-                match &res.row {
-                    QueryResultRow::SqlxMySql(row) => {
-                        use sqlx::Row;
-                        match row.try_get(column.as_str()) {
-                            Ok(v) => Ok(Some(v)),
-                            Err(_) => Ok(None),
-                        }
-                    }
-                }
-            }
-        }
-    };
-}
-
-try_getable!(bool);
-try_getable!(i8);
-try_getable!(i16);
-try_getable!(i32);
-try_getable!(i64);
-try_getable!(u8);
-try_getable!(u16);
-try_getable!(u32);
-try_getable!(u64);
-try_getable!(f32);
-try_getable!(f64);
-try_getable!(String);
-
-// QueryResult //
-
-impl QueryResult {
-    pub fn try_get<T>(&self, pre: &str, col: &str) -> Result<T, TypeErr>
-    where
-        T: TryGetable,
-    {
-        T::try_get(self, pre, col)
-    }
-}
-
-// TypeErr //
-
-impl Error for TypeErr {}
-
-impl fmt::Display for TypeErr {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{:?}", self)
-    }
-}
-
-impl From<sqlx::Error> for TypeErr {
-    fn from(_: sqlx::Error) -> TypeErr {
-        TypeErr
-    }
-}