fix(kingbase): restore column comments in table DDL

agents/drivers/kingbase-go/integration_test.go

@@ -54,6 +54,9 @@ func TestKingbaseIntegration(t *testing.T) {
 	})
 
 	mustExecute(t, server, "CREATE TABLE public."+quoteIdentifier(parent)+" (id integer PRIMARY KEY, name varchar(64) NOT NULL)")
+	mustExecute(t, server, "COMMENT ON TABLE public."+quoteIdentifier(parent)+" IS '订单父表'")
+	mustExecute(t, server, "COMMENT ON COLUMN public."+quoteIdentifier(parent)+".id IS '主键编号'")
+	mustExecute(t, server, "COMMENT ON COLUMN public."+quoteIdentifier(parent)+".name IS '客户''名称'")
 	mustExecute(t, server, "CREATE TABLE public."+quoteIdentifier(child)+" (id integer PRIMARY KEY, parent_id integer REFERENCES public."+quoteIdentifier(parent)+"(id))")
 	mustExecute(t, server, "CREATE INDEX "+quoteIdentifier(child+"_parent_idx")+" ON public."+quoteIdentifier(child)+"(parent_id)")
 	mustExecute(t, server, "CREATE VIEW public."+quoteIdentifier(view)+" AS SELECT id, name FROM public."+quoteIdentifier(parent))
@@ -67,6 +70,24 @@ func TestKingbaseIntegration(t *testing.T) {
 	if err != nil || len(columns) != 2 || !columns[0].IsPrimaryKey {
 		t.Fatalf("get columns failed: columns=%v err=%v", columns, err)
 	}
+	parentColumns, err := server.getColumns("public", parent)
+	if err != nil || len(parentColumns) != 2 || parentColumns[0].Comment == nil || *parentColumns[0].Comment != "主键编号" || parentColumns[1].Comment == nil || *parentColumns[1].Comment != "客户'名称" {
+		t.Fatalf("get commented columns failed: columns=%v err=%v", parentColumns, err)
+	}
+	ddl, err := server.getTableDDL("public", parent)
+	if err != nil {
+		t.Fatalf("get table DDL failed: %v", err)
+	}
+	qualifiedParent := quoteIdentifier("public") + "." + quoteIdentifier(parent)
+	for _, expected := range []string{
+		"COMMENT ON TABLE " + qualifiedParent + " IS '订单父表';",
+		"COMMENT ON COLUMN " + qualifiedParent + "." + quoteIdentifier("id") + " IS '主键编号';",
+		"COMMENT ON COLUMN " + qualifiedParent + "." + quoteIdentifier("name") + " IS '客户''名称';",
+	} {
+		if !strings.Contains(ddl, expected) {
+			t.Fatalf("table DDL missing %q:\n%s", expected, ddl)
+		}
+	}
 	indexes, err := server.listIndexes("public", child)
 	if err != nil || len(indexes) < 2 {
 		t.Fatalf("list indexes failed: indexes=%v err=%v", indexes, err)

agents/drivers/kingbase-go/kingbase_metadata.go

@@ -672,6 +672,11 @@ func (s *server) getTableDDL(schema, table string) (string, error) {
 	if err != nil {
 		return "", err
 	}
+	tableComment, _ := s.getTableComment(effective, table)
+	return renderTableDDL(effective, table, columns, tableComment), nil
+}
+
+func renderTableDDL(schema, table string, columns []columnInfo, tableComment *string) string {
 	definitions := make([]string, 0, len(columns)+1)
 	primary := []string{}
 	for _, column := range columns {
@@ -683,7 +688,18 @@ func (s *server) getTableDDL(schema, table string) (string, error) {
 	if len(primary) > 0 {
 		definitions = append(definitions, "PRIMARY KEY ("+strings.Join(primary, ", ")+")")
 	}
-	return "CREATE TABLE " + quoteIdentifier(effective) + "." + quoteIdentifier(table) + " (\n  " + strings.Join(definitions, ",\n  ") + "\n);", nil
+	qualifiedTable := quoteIdentifier(schema) + "." + quoteIdentifier(table)
+	ddl := "CREATE TABLE " + qualifiedTable + " (\n  " + strings.Join(definitions, ",\n  ") + "\n);"
+	if tableComment != nil && strings.TrimSpace(*tableComment) != "" {
+		ddl += "\nCOMMENT ON TABLE " + qualifiedTable + " IS " + quoteLiteral(*tableComment) + ";"
+	}
+	for _, column := range columns {
+		if column.Comment == nil || strings.TrimSpace(*column.Comment) == "" {
+			continue
+		}
+		ddl += "\nCOMMENT ON COLUMN " + qualifiedTable + "." + quoteIdentifier(column.Name) + " IS " + quoteLiteral(*column.Comment) + ";"
+	}
+	return ddl
 }
 
 func columnDDLDefinition(column columnInfo) string {

agents/drivers/kingbase-go/main_test.go

@@ -416,6 +416,38 @@ func TestTableDDLIncludesCatalogIdentityClause(t *testing.T) {
 	if !strings.Contains(ddl, `"id" integer GENERATED BY DEFAULT AS IDENTITY NOT NULL`) {
 		t.Fatalf("identity clause missing from table DDL: %s", ddl)
 	}
+	if !strings.Contains(ddl, `COMMENT ON TABLE "public"."orders" IS 'orders table';`) {
+		t.Fatalf("table comment missing from table DDL: %s", ddl)
+	}
+}
+
+func TestRenderTableDDLIncludesEscapedComments(t *testing.T) {
+	primaryComment := "主键'编号"
+	emptyComment := "  "
+	tableComment := "订单'表"
+	ddl := renderTableDDL(
+		`app"schema`,
+		`order"items`,
+		[]columnInfo{
+			{Name: `id"value`, DataType: "integer", IsNullable: false, IsPrimaryKey: true, Comment: &primaryComment},
+			{Name: "note", DataType: "text", IsNullable: true, Comment: &emptyComment},
+		},
+		&tableComment,
+	)
+
+	expected := []string{
+		`CREATE TABLE "app""schema"."order""items"`,
+		`COMMENT ON TABLE "app""schema"."order""items" IS '订单''表';`,
+		`COMMENT ON COLUMN "app""schema"."order""items"."id""value" IS '主键''编号';`,
+	}
+	for _, fragment := range expected {
+		if !strings.Contains(ddl, fragment) {
+			t.Fatalf("table DDL missing %q:\n%s", fragment, ddl)
+		}
+	}
+	if strings.Contains(ddl, `COMMENT ON COLUMN "app""schema"."order""items"."note"`) {
+		t.Fatalf("blank column comment must be omitted:\n%s", ddl)
+	}
 }
 
 func TestColumnDDLDefinitionPreservesCompatibilityExtras(t *testing.T) {