用sql脚本安全添加字段_MySQL

用sql脚本安全添加字段

CREATE PROCEDURE safe_add_col(tname VARCHAR(50),cname VARCHAR(50))

BEGIN

SET @a = '';

SELECT column_name into @a

FROM information_schema.columns

WHERE table_name = tname AND column_name = cname;

IF @a = '' THEN

alter table tbl_application_source_down add import_batch VARCHAR(14) DEFAULT '' NOT NULL;

END IF;

END;

call safe_add_col('user','real_name');

DROP PROCEDURE IF EXISTS safe_add_col;