From 486c344ba3750a9d2293372ad4e6f510e3371bf3 Mon Sep 17 00:00:00 2001
From: brookechen <brookechen@noreply.gitea.com>
Date: Tue, 11 Jul 2023 17:10:36 +0000
Subject: [PATCH] =?UTF-8?q?In=20SQLite3,=20Sync=20doesn't=20support=20Modi?=
 =?UTF-8?q?fy=20Column=EF=BC=9AError:=20near=20MODIFY:=20syntax=20error=20?=
 =?UTF-8?q?(#2267)?=
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rebase

Co-authored-by: brookechen <brookechen@noreply.gitea.io>
Co-authored-by: brookechen <brookechen@tencent.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-on: https://gitea.com/xorm/xorm/pulls/2267
Co-authored-by: brookechen <brookechen@noreply.gitea.com>
Co-committed-by: brookechen <brookechen@noreply.gitea.com>
---
 dialects/mysql.go           |  3 +++
 integrations/engine_test.go | 42 +++++++++++++++++++++++++++++++++++++
 sync.go                     |  5 ++++-
 3 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/dialects/mysql.go b/dialects/mysql.go
index 5663d1dd..82505707 100644
--- a/dialects/mysql.go
+++ b/dialects/mysql.go
@@ -397,6 +397,9 @@ func (db *mysql) AddColumnSQL(tableName string, col *schemas.Column) string {
 // ModifyColumnSQL returns a SQL to modify SQL
 func (db *mysql) ModifyColumnSQL(tableName string, col *schemas.Column) string {
 	s, _ := ColumnString(db.dialect, col, false, true)
+	if col.Comment != "" {
+		s += fmt.Sprintf(" COMMENT '%s'", col.Comment)
+	}
 	return fmt.Sprintf("ALTER TABLE %s MODIFY COLUMN %s", db.quoter.Quote(tableName), s)
 }
 
diff --git a/integrations/engine_test.go b/integrations/engine_test.go
index 730a424e..86ed7344 100644
--- a/integrations/engine_test.go
+++ b/integrations/engine_test.go
@@ -289,6 +289,48 @@ func TestGetColumnsComment(t *testing.T) {
 	assert.Zero(t, noComment)
 }
 
+type TestCommentUpdate struct {
+	HasComment int `xorm:"bigint comment('this is a comment before update')"`
+}
+
+func (m *TestCommentUpdate) TableName() string {
+	return "test_comment_struct"
+}
+
+type TestCommentUpdate2 struct {
+	HasComment int `xorm:"bigint comment('this is a comment after update')"`
+}
+
+func (m *TestCommentUpdate2) TableName() string {
+	return "test_comment_struct"
+}
+
+func TestColumnCommentUpdate(t *testing.T) {
+	comment := "this is a comment after update"
+	assertSync(t, new(TestCommentUpdate))
+	assert.NoError(t, testEngine.Sync2(new(TestCommentUpdate2))) // modify table column comment
+
+	switch testEngine.Dialect().URI().DBType {
+	case schemas.POSTGRES, schemas.MYSQL: // only postgres / mysql dialect implement the feature of modify comment in postgres.ModifyColumnSQL
+	default:
+		t.Skip()
+		return
+	}
+	tables, err := testEngine.DBMetas()
+	assert.NoError(t, err)
+	tableName := "test_comment_struct"
+	var hasComment string
+	for _, table := range tables {
+		if table.Name == tableName {
+			col := table.GetColumn(testEngine.GetColumnMapper().Obj2Table("HasComment"))
+			assert.NotNil(t, col)
+			hasComment = col.Comment
+			break
+		}
+	}
+	assert.Equal(t, comment, hasComment)
+}
+
 func TestGetColumnsLength(t *testing.T) {
 	var max_length int64
 	switch testEngine.Dialect().URI().DBType {
diff --git a/sync.go b/sync.go
index 6583e341..11e75404 100644
--- a/sync.go
+++ b/sync.go
@@ -181,7 +181,10 @@ func (session *Session) SyncWithOptions(opts SyncOptions, beans ...interface{})
 					}
 				}
 			} else if col.Comment != oriCol.Comment {
-				_, err = session.exec(engine.dialect.ModifyColumnSQL(tbNameWithSchema, col))
+				if engine.dialect.URI().DBType == schemas.POSTGRES ||
+					engine.dialect.URI().DBType == schemas.MYSQL {
+					_, err = session.exec(engine.dialect.ModifyColumnSQL(tbNameWithSchema, col))
+				}
 			}
 
 			if col.Default != oriCol.Default {