Merge remote-tracking branch 'origin/dev' into dev

internal/db/dameng_columns_runtime_test.go

@@ -51,6 +51,22 @@ func (damengColumnsMetadataConn) QueryContext(_ context.Context, query string, _
 	failAutoIncrementQuery := damengColumnsMetadataQueryState.failAutoIncrementQuery
 	damengColumnsMetadataQueryState.Unlock()
 
+	if strings.Contains(query, "DBMS_METADATA.GET_DDL") {
+		return &damengColumnsMetadataRows{
+			columns: []string{"DDL"},
+			values: [][]driver.Value{{`CREATE TABLE "BIZ"."ORDERS" (
+  "ID" NUMBER NOT NULL
+)`}},
+		}, nil
+	}
+
+	if strings.Contains(query, "all_tab_comments") {
+		return &damengColumnsMetadataRows{
+			columns: []string{"TABLE_COMMENT"},
+			values:  [][]driver.Value{{"订单'归档"}},
+		}, nil
+	}
+
 	if strings.Contains(query, "SYS.SYSCOLUMNS") {
 		if failAutoIncrementQuery {
 			return nil, errors.New("insufficient privilege for SYS.SYSCOLUMNS")
@@ -174,6 +190,33 @@ func TestDamengGetColumnsKeepsBaseMetadataWhenAutoIncrementQueryFails(t *testing
 	}
 }
 
+func TestDamengGetCreateStatementAppendsTableComment(t *testing.T) {
+	resetDamengColumnsMetadataQueryState(t, false)
+
+	damengDB := &DamengDB{conn: openDamengColumnsMetadataDB(t)}
+	ddl, err := damengDB.GetCreateStatement("biz", "orders")
+	if err != nil {
+		t.Fatalf("GetCreateStatement returned error: %v", err)
+	}
+
+	for _, want := range []string{
+		`CREATE TABLE "BIZ"."ORDERS"`,
+		`COMMENT ON TABLE "BIZ"."ORDERS" IS '订单''归档';`,
+	} {
+		if !strings.Contains(ddl, want) {
+			t.Fatalf("expected DDL to contain %q, got: %s", want, ddl)
+		}
+	}
+
+	queries := damengColumnsMetadataQueries()
+	if len(queries) != 2 || !strings.Contains(queries[1], "all_tab_comments") {
+		t.Fatalf("expected DDL and table comment metadata queries, got=%v", queries)
+	}
+	if !strings.Contains(queries[1], "owner = 'BIZ'") || !strings.Contains(queries[1], "table_name = 'ORDERS'") {
+		t.Fatalf("expected normalized schema and table comment predicates, got=%s", queries[1])
+	}
+}
+
 func TestDamengGetIndexesUsesIndexOwnerJoinAndMapsColumnOrder(t *testing.T) {
 	resetDamengColumnsMetadataQueryState(t, false)
 

internal/db/dameng_impl.go

@@ -305,7 +305,17 @@ func (d *DamengDB) GetCreateStatement(dbName, tableName string) (string, error)
 
 	if len(data) > 0 {
 		if val, ok := data[0]["DDL"]; ok {
-			return fmt.Sprintf("%v", val), nil
+			ddl := fmt.Sprintf("%v", val)
+			commentData, _, commentErr := d.Query(buildDamengTableCommentQuery(dbName, tableName))
+			if commentErr != nil {
+				logger.Warnf("达梦 GetCreateStatement 表注释元数据查询失败，已返回基础 DDL：%v", commentErr)
+				return ddl, nil
+			}
+			if len(commentData) == 0 {
+				return ddl, nil
+			}
+			comment := getDamengRowString(commentData[0], "TABLE_COMMENT", "COMMENT", "COMMENTS")
+			return appendDamengTableCommentDDL(ddl, dbName, tableName, comment), nil
 		}
 	}
 	return "", localizedDatabaseRuntimeError("db.backend.error.create_table_statement_not_found", nil)

internal/db/dameng_metadata.go

@@ -148,6 +148,43 @@ func buildDamengColumnsQuery(dbName, tableName string) string {
 		ORDER BY c.column_id`, upperDBName, upperTableName, upperDBName, upperTableName, upperDBName, upperTableName)
 }
 
+func buildDamengTableCommentQuery(dbName, tableName string) string {
+	upperTableName := strings.ReplaceAll(strings.ToUpper(strings.TrimSpace(tableName)), "'", "''")
+	upperDBName := strings.ReplaceAll(strings.ToUpper(strings.TrimSpace(dbName)), "'", "''")
+	if upperDBName == "" {
+		return fmt.Sprintf(`SELECT comments AS "TABLE_COMMENT"
+			FROM user_tab_comments
+			WHERE table_name = '%s' AND comments IS NOT NULL`, upperTableName)
+	}
+	return fmt.Sprintf(`SELECT comments AS "TABLE_COMMENT"
+		FROM all_tab_comments
+		WHERE owner = '%s' AND table_name = '%s' AND comments IS NOT NULL`, upperDBName, upperTableName)
+}
+
+func appendDamengTableCommentDDL(ddl, dbName, tableName, comment string) string {
+	baseDDL := strings.TrimSpace(ddl)
+	comment = strings.TrimSpace(comment)
+	if baseDDL == "" || comment == "" || strings.Contains(strings.ToUpper(baseDDL), "COMMENT ON TABLE ") {
+		return baseDDL
+	}
+
+	quoteIdentifier := func(value string) string {
+		value = strings.ToUpper(strings.TrimSpace(value))
+		return `"` + strings.ReplaceAll(value, `"`, `""`) + `"`
+	}
+	tableRef := quoteIdentifier(tableName)
+	if strings.TrimSpace(dbName) != "" {
+		tableRef = quoteIdentifier(dbName) + "." + tableRef
+	}
+
+	baseDDL = strings.TrimRight(baseDDL, " \t\r\n")
+	if !strings.HasSuffix(baseDDL, ";") && !strings.HasSuffix(baseDDL, "/") {
+		baseDDL += ";"
+	}
+	escapedComment := strings.ReplaceAll(comment, "'", "''")
+	return fmt.Sprintf("%s\n\nCOMMENT ON TABLE %s IS '%s';", baseDDL, tableRef, escapedComment)
+}
+
 // buildDamengAutoIncrementColumnsQuery reads the stable system-table flag that
 // records both IDENTITY and AUTO_INCREMENT columns. It intentionally remains a
 // separate query so restricted accounts can still load base column metadata.

internal/db/dameng_metadata_test.go

@@ -146,6 +146,37 @@ func TestBuildDamengColumnsQuery_IncludesColumnCommentsJoin(t *testing.T) {
 	}
 }
 
+func TestBuildDamengTableCommentQueryUsesSchemaAppropriateDictionaryView(t *testing.T) {
+	t.Parallel()
+
+	userQuery := buildDamengTableCommentQuery("", "orders")
+	if !strings.Contains(userQuery, "FROM user_tab_comments") || !strings.Contains(userQuery, "table_name = 'ORDERS'") {
+		t.Fatalf("expected current-schema table comment query, got: %s", userQuery)
+	}
+
+	allQuery := buildDamengTableCommentQuery("biz", "orders")
+	if !strings.Contains(allQuery, "FROM all_tab_comments") || !strings.Contains(allQuery, "owner = 'BIZ'") || !strings.Contains(allQuery, "table_name = 'ORDERS'") {
+		t.Fatalf("expected schema table comment query, got: %s", allQuery)
+	}
+}
+
+func TestAppendDamengTableCommentDDLAvoidsDuplicateAndEscapesLiteral(t *testing.T) {
+	t.Parallel()
+
+	ddl := appendDamengTableCommentDDL(`CREATE TABLE "BIZ"."ORDERS" ("ID" NUMBER)`, "biz", "orders", "订单'归档")
+	if !strings.Contains(ddl, `COMMENT ON TABLE "BIZ"."ORDERS" IS '订单''归档';`) {
+		t.Fatalf("expected escaped table comment DDL, got: %s", ddl)
+	}
+	if !strings.Contains(ddl, "(\"ID\" NUMBER);\n\nCOMMENT ON TABLE") {
+		t.Fatalf("expected create statement terminator before table comment, got: %s", ddl)
+	}
+
+	duplicated := appendDamengTableCommentDDL(ddl, "biz", "orders", "新备注")
+	if duplicated != ddl {
+		t.Fatalf("expected existing table comment DDL to remain unchanged, got: %s", duplicated)
+	}
+}
+
 func TestBuildDamengColumnDefinitions_MapsComment(t *testing.T) {
 	t.Parallel()