用sql脚本安全添加字段_MySQL

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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;    

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