feat(mariadb): support RETURNING clause in DELETE statement

dialect/feature/feature.go

@@ -34,4 +34,5 @@ const (
 	CompositeIn      // ... WHERE (A,B) IN ((N, NN), (N, NN)...)
 	UpdateOrderLimit // UPDATE ... ORDER BY ... LIMIT ...
 	DeleteOrderLimit // DELETE ... ORDER BY ... LIMIT ...
+	DeleteReturning
 )

dialect/mysqldialect/dialect.go

@@ -79,6 +79,9 @@ func (d *Dialect) Init(db *sql.DB) {
 
 	if strings.Contains(version, "MariaDB") {
 		version = semver.MajorMinor("v" + cleanupVersion(version))
+		if semver.Compare(version, "v10.0.5") >= 0 {
+			d.features |= feature.DeleteReturning
+		}
 		if semver.Compare(version, "v10.5.0") >= 0 {
 			d.features |= feature.InsertReturning
 		}

dialect/oracledialect/dialect.go

@@ -40,7 +40,8 @@ func New() *Dialect {
 		feature.TableNotExists |
 		feature.SelectExists |
 		feature.AutoIncrement |
-		feature.CompositeIn
+		feature.CompositeIn |
+		feature.DeleteReturning
 	return d
 }
 

dialect/pgdialect/dialect.go

@@ -53,7 +53,8 @@ func New() *Dialect {
 		feature.InsertOnConflict |
 		feature.SelectExists |
 		feature.GeneratedIdentity |
-		feature.CompositeIn
+		feature.CompositeIn |
+		feature.DeleteReturning
 	return d
 }
 

dialect/sqlitedialect/dialect.go

@@ -40,7 +40,8 @@ func New() *Dialect {
 		feature.TableNotExists |
 		feature.SelectExists |
 		feature.AutoIncrement |
-		feature.CompositeIn
+		feature.CompositeIn |
+		feature.DeleteReturning
 	return d
 }
 

internal/dbtest/query_test.go

@@ -1590,6 +1590,12 @@ func TestQuery(t *testing.T) {
 				return db.NewUpdate().Model(new(Story)).Set("name = ?", "new-name").WherePK().Order("id").Limit(1)
 			},
 		},
+		{
+			id: 172,
+			query: func(db *bun.DB) schema.QueryAppender {
+				return db.NewDelete().Model(&Model{}).WherePK().Returning("*")
+			},
+		},
 	}
 
 	timeRE := regexp.MustCompile(`'2\d{3}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}(\.\d+)?(\+\d{2}:\d{2})?'`)

internal/dbtest/testdata/snapshots/TestQuery-mariadb-172

@@ -0,0 +1 @@
+DELETE FROM `models` WHERE (`id` = NULL) RETURNING *

internal/dbtest/testdata/snapshots/TestQuery-mssql2019-172

@@ -0,0 +1 @@
+bun: returning is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-mysql5-172

@@ -0,0 +1 @@
+bun: returning is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-mysql8-172

@@ -0,0 +1 @@
+bun: returning is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-pg-172

@@ -0,0 +1 @@
+DELETE FROM "models" AS "model" WHERE ("model"."id" = NULL) RETURNING *

internal/dbtest/testdata/snapshots/TestQuery-pgx-172

@@ -0,0 +1 @@
+DELETE FROM "models" AS "model" WHERE ("model"."id" = NULL) RETURNING *

internal/dbtest/testdata/snapshots/TestQuery-sqlite-172

@@ -0,0 +1 @@
+DELETE FROM "models" AS "model" WHERE ("model"."id" = NULL) RETURNING *

query_delete.go

@@ -163,6 +163,11 @@ func (q *DeleteQuery) Limit(n int) *DeleteQuery {
 //
 // To suppress the auto-generated RETURNING clause, use `Returning("NULL")`.
 func (q *DeleteQuery) Returning(query string, args ...interface{}) *DeleteQuery {
+	if !q.hasFeature(feature.DeleteReturning) {
+		q.err = errors.New("bun: returning is not supported for current dialect")
+		return q
+	}
+
 	q.addReturning(schema.SafeQuery(query, args))
 	return q
 }
@@ -249,7 +254,7 @@ func (q *DeleteQuery) AppendQuery(fmter schema.Formatter, b []byte) (_ []byte, e
 		return nil, err
 	}
 
-	if q.hasFeature(feature.Returning) && q.hasReturning() {
+	if q.hasFeature(feature.DeleteReturning) && q.hasReturning() {
 		b = append(b, " RETURNING "...)
 		b, err = q.appendReturning(fmter, b)
 		if err != nil {
@@ -311,7 +316,7 @@ func (q *DeleteQuery) scanOrExec(
 		return nil, err
 	}
 
-	useScan := hasDest || (q.hasReturning() && q.hasFeature(feature.Returning|feature.Output))
+	useScan := hasDest || (q.hasReturning() && q.hasFeature(feature.DeleteReturning|feature.Output))
 	var model Model
 
 	if useScan {