Merge pull request SeaQL#194 from SpyrosRoum/returning-for-sqlite

Implement `RETURNING` for SQLite

src/backend/mysql/query.rs

@@ -1,3 +1,11 @@
 use super::*;
 
-impl QueryBuilder for MysqlQueryBuilder {}
+impl QueryBuilder for MysqlQueryBuilder {
+    fn prepare_returning(
+        &self,
+        _returning: &[SelectExpr],
+        _sql: &mut SqlWriter,
+        _collector: &mut dyn FnMut(Value),
+    ) {
+    }
+}

src/backend/postgres/query.rs

@@ -6,24 +6,6 @@ impl QueryBuilder for PostgresQueryBuilder {
         ("$", true)
     }
 
-    fn prepare_returning(
-        &self,
-        returning: &[SelectExpr],
-        sql: &mut SqlWriter,
-        collector: &mut dyn FnMut(Value),
-    ) {
-        if !returning.is_empty() {
-            write!(sql, " RETURNING ").unwrap();
-            returning.iter().fold(true, |first, expr| {
-                if !first {
-                    write!(sql, ", ").unwrap()
-                }
-                self.prepare_select_expr(expr, sql, collector);
-                false
-            });
-        }
-    }
-
     fn if_null_function(&self) -> &str {
         "COALESCE"
     }

src/backend/query_builder.rs

@@ -793,10 +793,20 @@ pub trait QueryBuilder: QuotedBuilder {
     /// Hook to insert "RETURNING" statements.
     fn prepare_returning(
         &self,
-        _returning: &[SelectExpr],
-        _sql: &mut SqlWriter,
-        _collector: &mut dyn FnMut(Value),
+        returning: &[SelectExpr],
+        sql: &mut SqlWriter,
+        collector: &mut dyn FnMut(Value),
     ) {
+        if !returning.is_empty() {
+            write!(sql, " RETURNING ").unwrap();
+            returning.iter().fold(true, |first, expr| {
+                if !first {
+                    write!(sql, ", ").unwrap()
+                }
+                self.prepare_select_expr(expr, sql, collector);
+                false
+            });
+        }
     }
 
     #[doc(hidden)]

src/query/delete.rs

@@ -100,7 +100,15 @@ impl DeleteStatement {
         self
     }
 
-    /// RETURNING expressions. Postgres only.
+    /// RETURNING expressions.
+    ///
+    /// ## Note:
+    /// Works on
+    /// * PostgreSQL
+    /// * SQLite
+    ///     - SQLite version >= 3.35.0 and
+    ///     - Not with sqlx, see [issue](https://github.com/launchbadge/sqlx/issues/1531)
+    ///     - **Note that sea-query won't try to enforce either of these constraints**
     ///
     /// ```
     /// use sea_query::{tests_cfg::*, *};
@@ -121,17 +129,25 @@ impl DeleteStatement {
     /// );
     /// assert_eq!(
     ///     query.to_string(SqliteQueryBuilder),
-    ///     r#"DELETE FROM `glyph` WHERE `id` = 1"#
+    ///     r#"DELETE FROM `glyph` WHERE `id` = 1 RETURNING `id`"#
     /// );
     /// ```
     pub fn returning(&mut self, select: SelectStatement) -> &mut Self {
         self.returning = select.selects;
         self
     }
 
-    /// RETURNING a column after delete. Postgres only.
+    /// RETURNING a column after delete.
     /// Wrapper over [`DeleteStatement::returning()`].
     ///
+    /// ## Note:
+    /// Works on
+    /// * PostgreSQL
+    /// * SQLite
+    ///     - SQLite version >= 3.35.0 and
+    ///     - Not with sqlx, see [issue](https://github.com/launchbadge/sqlx/issues/1531)
+    ///     - **Note that sea-query won't try to enforce either of these constraints**
+    ///
     /// ```
     /// use sea_query::{tests_cfg::*, *};
     ///
@@ -151,7 +167,7 @@ impl DeleteStatement {
     /// );
     /// assert_eq!(
     ///     query.to_string(SqliteQueryBuilder),
-    ///     r#"DELETE FROM `glyph` WHERE `id` = 1"#
+    ///     r#"DELETE FROM `glyph` WHERE `id` = 1 RETURNING `id`"#
     /// );
     /// ```
     pub fn returning_col<C>(&mut self, col: C) -> &mut Self

src/query/insert.rs

@@ -179,7 +179,15 @@ impl InsertStatement {
         self.exprs(values).unwrap()
     }
 
-    /// RETURNING expressions. Postgres only.
+    /// RETURNING expressions.
+    ///
+    /// ## Note:
+    /// Works on
+    /// * PostgreSQL
+    /// * SQLite
+    ///     - SQLite version >= 3.35.0 and
+    ///     - Not with sqlx, see [issue](https://github.com/launchbadge/sqlx/issues/1531)
+    ///     - **Note that sea-query won't try to enforce either of these constraints**
     ///
     /// ```
     /// use sea_query::{tests_cfg::*, *};
@@ -201,17 +209,25 @@ impl InsertStatement {
     /// );
     /// assert_eq!(
     ///     query.to_string(SqliteQueryBuilder),
-    ///     "INSERT INTO `glyph` (`image`) VALUES ('12A')"
+    ///     "INSERT INTO `glyph` (`image`) VALUES ('12A') RETURNING `id`"
     /// );
     /// ```
     pub fn returning(&mut self, select: SelectStatement) -> &mut Self {
         self.returning = select.selects;
         self
     }
 
-    /// RETURNING a column after insertion. Postgres only. This is equivalent to MySQL's LAST_INSERT_ID.
+    /// RETURNING a column after insertion. This is equivalent to MySQL's LAST_INSERT_ID.
     /// Wrapper over [`InsertStatement::returning()`].
     ///
+    /// ## Note:
+    /// Works on
+    /// * PostgreSQL
+    /// * SQLite
+    ///     - SQLite version >= 3.35.0 and
+    ///     - Not with sqlx, see [issue](https://github.com/launchbadge/sqlx/issues/1531)
+    ///     - **Note that sea-query won't try to enforce either of these constraints**
+    ///
     /// ```
     /// use sea_query::{tests_cfg::*, *};
     ///
@@ -232,7 +248,7 @@ impl InsertStatement {
     /// );
     /// assert_eq!(
     ///     query.to_string(SqliteQueryBuilder),
-    ///     "INSERT INTO `glyph` (`image`) VALUES ('12A')"
+    ///     "INSERT INTO `glyph` (`image`) VALUES ('12A') RETURNING `id`"
     /// );
     /// ```
     pub fn returning_col<C>(&mut self, col: C) -> &mut Self

src/query/update.rs

@@ -223,7 +223,15 @@ impl UpdateStatement {
         self
     }
 
-    /// RETURNING expressions. Postgres only.
+    /// RETURNING expressions.
+    ///
+    /// ## Note:
+    /// Works on
+    /// * PostgreSQL
+    /// * SQLite
+    ///     - SQLite version >= 3.35.0 and
+    ///     - Not with sqlx, see [issue](https://github.com/launchbadge/sqlx/issues/1531)
+    ///     - **Note that sea-query won't try to enforce either of these constraints**
     ///
     /// ```
     /// use sea_query::{tests_cfg::*, *};
@@ -246,17 +254,25 @@ impl UpdateStatement {
     /// );
     /// assert_eq!(
     ///     query.to_string(SqliteQueryBuilder),
-    ///     r#"UPDATE `glyph` SET `aspect` = 2.1345, `image` = '235m' WHERE `id` = 1"#
+    ///     r#"UPDATE `glyph` SET `aspect` = 2.1345, `image` = '235m' WHERE `id` = 1 RETURNING `id`"#
     /// );
     /// ```
     pub fn returning(&mut self, select: SelectStatement) -> &mut Self {
         self.returning = select.selects;
         self
     }
 
-    /// RETURNING a column after update. Postgres only.
+    /// RETURNING a column after update.
     /// Wrapper over [`UpdateStatement::returning()`].
     ///
+    /// ## Note:
+    /// Works on
+    /// * PostgreSQL
+    /// * SQLite
+    ///     - SQLite version >= 3.35.0 and
+    ///     - Not with sqlx, see [issue](https://github.com/launchbadge/sqlx/issues/1531)
+    ///     - **Note that sea-query won't try to enforce either of these constraints**
+    ///
     /// ```
     /// use sea_query::{tests_cfg::*, *};
     ///
@@ -279,7 +295,7 @@ impl UpdateStatement {
     /// );
     /// assert_eq!(
     ///     query.to_string(SqliteQueryBuilder),
-    ///     r#"UPDATE `glyph` SET `aspect` = 2.1345, `image` = '235m' WHERE `id` = 1"#
+    ///     r#"UPDATE `glyph` SET `aspect` = 2.1345, `image` = '235m' WHERE `id` = 1 RETURNING `id`"#
     /// );
     /// ```
     pub fn returning_col<C>(&mut self, col: C) -> &mut Self