我想在 PostgreSQL 数据库中将所有列名重命名为小写，我刚刚编写了一个 sql 函数。下面是代码。
CREATE OR REPLACE FUNCTION update_column_names() RETURNS boolean AS $$
DECLARE
aRow RECORD;
aRow2 RECORD;
tbl_name TEXT;
col_name TEXT;
new_col_name TEXT;
BEGIN
FOR aRow IN select table_name from information_schema.tables where table_schema='public' and table_type='BASE TABLE' LOOP
SELECT aRow.table_name INTO tbl_name from current_catalog;
FOR aRow2 IN select column_name from information_schema.columns where table_schema='public' and table_name = aRow.table_name LOOP
SELECT aRow2.column_name INTO col_name from current_catalog;
new_col_name:=lower(col_name);
RAISE NOTICE 'Table name:%',tbl_name;
RAISE NOTICE 'Column name:%',aRow2.column_name;
RAISE NOTICE 'New column name:%',new_col_name;
ALTER TABLE tbl_name RENAME COLUMN col_name TO new_col_name;
END LOOP;
END LOOP;
RETURN true;
END;
$$ LANGUAGE plpgsql;
上面的代码给出了关系 tbl_name 不存在。代码有什么问题？