On error use information_schema in MySql function

Question

Can you tell me what's wrong with this MySQL function?

I followed the link How can I “select *” from a table in MySQL but omit certain columns? to define a function in MySQL. But I got an error "no database selected".

DELIMITER $$
CREATE FUNCTION getTableColumns(_schemaName varchar(100), _tableName varchar(100), _omitColumns varchar(200)) RETURNS varchar(5000)
BEGIN
    SELECT REPLACE(GROUP_CONCAT(COLUMN_NAME), '_omitColumns,', '')
    FROM information_schema.columns 
    WHERE table_schema = _schemaName AND table_name = _tableName
    INTO results;
    RETURN results;
END$$

Error Code: 1046. No database selected Select the default DB to be used by double-clicking its name in the SCHEMAS list in the sidebar.

Answer 1

只需添加数据库名称和函数名称

your_database_name.getTableColumns(......