Delete Limit with start will return error because it's not supported by database (#1895)

Fix #1894

Reviewed-on: https://gitea.com/xorm/xorm/pulls/1895

.gitea/workflows/test-cockroach.yml

@@ -43,6 +43,7 @@ jobs:
           TEST_COCKROACH_DBNAME: xorm_test
           TEST_COCKROACH_USERNAME: root
           TEST_COCKROACH_PASSWORD:
+          IGNORE_TEST_DELETE_LIMIT: true
         run: sleep 20 && make test-cockroach
 
     services:

integrations/session_delete_test.go

@@ -5,6 +5,7 @@
 package integrations
 
 import (
+	"os"
 	"testing"
 	"time"
 
@@ -70,6 +71,63 @@ func TestDelete(t *testing.T) {
 	assert.False(t, has)
 }
 
+func TestDeleteLimit(t *testing.T) {
+	assert.NoError(t, PrepareEngine())
+
+	if testEngine.Dialect().URI().DBType == schemas.MSSQL || os.Getenv("IGNORE_TEST_DELETE_LIMIT") == "true" {
+		t.Skip()
+		return
+	}
+
+	type UserinfoDeleteLimit struct {
+		Uid   int64 `xorm:"id pk not null autoincr"`
+		IsMan bool
+	}
+
+	assert.NoError(t, testEngine.Sync2(new(UserinfoDeleteLimit)))
+
+	session := testEngine.NewSession()
+	defer session.Close()
+
+	var err error
+	if testEngine.Dialect().URI().DBType == schemas.MSSQL {
+		err = session.Begin()
+		assert.NoError(t, err)
+		_, err = session.Exec("SET IDENTITY_INSERT userinfo_delete_limit ON")
+		assert.NoError(t, err)
+	}
+
+	user := UserinfoDeleteLimit{Uid: 1, IsMan: true}
+	cnt, err := session.Insert(&user)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 1, cnt)
+
+	user2 := UserinfoDeleteLimit{Uid: 2}
+	cnt, err = session.Insert(&user2)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 1, cnt)
+
+	if testEngine.Dialect().URI().DBType == schemas.MSSQL {
+		err = session.Commit()
+		assert.NoError(t, err)
+	}
+
+	cnt, err = testEngine.Limit(1, 1).Delete(&UserinfoDeleteLimit{})
+	assert.Error(t, err)
+	assert.EqualValues(t, 0, cnt)
+
+	cnt, err = testEngine.Limit(1).Desc("id").Delete(&UserinfoDeleteLimit{})
+	assert.NoError(t, err)
+	assert.EqualValues(t, 1, cnt)
+
+	var users []UserinfoDeleteLimit
+	err = testEngine.Find(&users)
+	assert.NoError(t, err)
+	assert.EqualValues(t, 1, len(users))
+	assert.EqualValues(t, 1, users[0].Uid)
+	assert.EqualValues(t, true, users[0].IsMan)
+}
+
 func TestDeleted(t *testing.T) {
 	assert.NoError(t, PrepareEngine())
 

internal/statements/delete.go

@@ -20,6 +20,9 @@ func (statement *Statement) writeDeleteOrder(w *builder.BytesWriter) error {
 	}
 
 	if statement.LimitN != nil && *statement.LimitN > 0 {
+		if statement.Start > 0 {
+			return fmt.Errorf("Delete with Limit start is unsupported")
+		}
 		limitNValue := *statement.LimitN
 		if _, err := fmt.Fprintf(w, " LIMIT %d", limitNValue); err != nil {
 			return err