🐛 fix(ddl): 修复金仓建表语句缺少字段备注

- 在 fallback DDL 中追加字段备注语句
- 生成 COMMENT ON COLUMN 并处理单引号转义
- 补充金仓字段备注回归测试
Refs #459

internal/app/methods_db.go

@@ -1105,6 +1105,7 @@ func buildFallbackCreateStatement(dbType string, schemaName string, tableName st
 
 	qualifiedTable := quoteTableIdentByType(dbType, schemaName, table)
 	columnLines := make([]string, 0, len(columns)+1)
+	columnCommentLines := make([]string, 0, len(columns))
 	primaryKeys := make([]string, 0, 2)
 
 	for _, col := range columns {
@@ -1131,6 +1132,9 @@ func buildFallbackCreateStatement(dbType string, schemaName string, tableName st
 		}
 
 		columnLines = append(columnLines, "  "+strings.Join(defParts, " "))
+		if commentSQL := buildFallbackColumnCommentStatement(dbType, qualifiedTable, colNameRaw, col.Comment); commentSQL != "" {
+			columnCommentLines = append(columnCommentLines, commentSQL)
+		}
 		if strings.EqualFold(strings.TrimSpace(col.Key), "PRI") {
 			primaryKeys = append(primaryKeys, colName)
 		}
@@ -1149,9 +1153,23 @@ func buildFallbackCreateStatement(dbType string, schemaName string, tableName st
 	ddl.WriteString(" (\n")
 	ddl.WriteString(strings.Join(columnLines, ",\n"))
 	ddl.WriteString("\n);")
+	if len(columnCommentLines) > 0 {
+		ddl.WriteString("\n")
+		ddl.WriteString(strings.Join(columnCommentLines, "\n"))
+	}
 	return ddl.String(), nil
 }
 
+func buildFallbackColumnCommentStatement(dbType string, qualifiedTable string, columnName string, comment string) string {
+	colName := strings.TrimSpace(columnName)
+	commentText := strings.TrimSpace(comment)
+	if colName == "" || commentText == "" {
+		return ""
+	}
+	columnRef := fmt.Sprintf("%s.%s", qualifiedTable, quoteIdentByType(dbType, colName))
+	return fmt.Sprintf("COMMENT ON COLUMN %s IS '%s';", columnRef, strings.ReplaceAll(commentText, "'", "''"))
+}
+
 func (a *App) DBGetColumns(config connection.ConnectionConfig, dbName string, tableName string) connection.QueryResult {
 	runConfig := normalizeRunConfig(config, dbName)
 

internal/app/methods_db_create_statement_test.go

@@ -172,6 +172,35 @@ func TestResolveCreateStatementWithFallback_CustomKingbaseUsesPublicSchema(t *te
 	}
 }
 
+func TestResolveCreateStatementWithFallback_KingbaseIncludesColumnComments(t *testing.T) {
+	t.Parallel()
+
+	dbInst := &fakeCreateStatementDB{
+		createSQL: "SHOW CREATE TABLE not directly supported in Kingbase/Postgres via SQL",
+		columns: []connection.ColumnDefinition{
+			{Name: "mes_third_sys_log_id", Type: "bigint", Nullable: "NO", Key: "PRI", Comment: "主键"},
+			{Name: "api_name", Type: "character varying(100 char)", Nullable: "YES", Comment: "接口名称"},
+			{Name: "request_param", Type: "longtext", Nullable: "YES", Comment: "请求参数's"},
+		},
+	}
+
+	ddl, err := resolveCreateStatementWithFallback(dbInst, connection.ConnectionConfig{
+		Type: "kingbase",
+	}, "demo_db", "ldf_server.mes_third_sys_log")
+	if err != nil {
+		t.Fatalf("resolveCreateStatementWithFallback() unexpected error: %v", err)
+	}
+	for _, want := range []string{
+		`COMMENT ON COLUMN ldf_server.mes_third_sys_log.mes_third_sys_log_id IS '主键';`,
+		`COMMENT ON COLUMN ldf_server.mes_third_sys_log.api_name IS '接口名称';`,
+		`COMMENT ON COLUMN ldf_server.mes_third_sys_log.request_param IS '请求参数''s';`,
+	} {
+		if !strings.Contains(ddl, want) {
+			t.Fatalf("expected fallback DDL to contain %q, got: %s", want, ddl)
+		}
+	}
+}
+
 func TestResolveCreateStatementWithFallback_KeepQualifiedSchema(t *testing.T) {
 	t.Parallel()