1.存储过程：将数据库中表存量数据中值为空的公共字段批量填充默认值

1.建立存储过程

程序如下：

DELIMITER $
CREATE PROCEDURE add_property (IN database_name VARCHAR (10),IN filed_name VARCHAR(20),IN default_value VARCHAR(20)) 
BEGIN 
  DECLARE cnt INT DEFAULT 0;
  DECLARE tb VARCHAR (20) ;
  DECLARE done INT DEFAULT FALSE ;
  DECLARE cur CURSOR FOR 
  SELECT 
    table_name 
  FROM
    information_schema.tables 
  WHERE table_schema = database_name ;
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE ;
  OPEN cur ;
  posLoop :
  LOOP
    FETCH cur INTO tb ;
    IF done 
    THEN LEAVE posLoop ;
    END IF ;
    -- 定义关键sql语句--
    SET @_SQL7 =