【数据库-MySql】根据列的类型来统一修改数据库所有表的数据

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#如果存在 UpdateDataByColumnType 存储过程则删除 UpdateDataByColumnType 存储过程  
drop procedure if exists UpdateDataByColumnType; 
#如果存在 tmpTable 临时表则删除 UpdateDataByColumnType 临时表  
DROP TABLE if EXISTS tmpTable;  
#创建 UpdateDataByColumnType 存储过程  
create procedure UpdateDataByColumnType(db char(20))  
begin  
    #申明变量  
    DECLARE tntmp VARCHAR(100);        
    DECLARE tctmp VARCHAR(100); 
		DECLARE indexx int;    
    #创建临时表  
    create table tmpTable (tablename VARCHAR(1000),columnsname VARCHAR(1000),flag int);   
    #清空临时表  
    truncate TABLE tmpTable;  
		
    #将需要清空的表插入到临时表  
    INSERT INTO tmpTable(tablename ,columnsname, flag )
		(SELECT a.TABLE_NAME,a.COLUMN_NAME,0 as flag FROM information_schema.COLUMNS as a
		left JOIN information_schema.TABLES as b on a.TABLE_NAME = b.TABLE_NAME and a.TABLE_SCHEMA = b.TABLE_SCHEMA
		WHERE a.table_schema = db and a.DATA_TYPE in ('datetime','timestamp') and b.TABLE_TYPE ="BASE TABLE");  
          
    #循环获取所有的表明以及删除状态      
    SELECT tablename,columnsname into tntmp,tctmp FROM tmpTable WHERE flag = 0 limit 1;  
		
		WHILE tntmp <> '' and tctmp <> '' DO   
			#拼写删除语句  
			set @sqlText := concat("update ",tntmp," set ",tctmp ,"='1990-01-01 00:00:00' where ",tctmp," is NULL;");  	  
			prepare stmt from @sqlText;  
			#执行语句  
			execute stmt;  
			#释放删除语句  
			deallocate prepare stmt;  
			#更新表状态  
			UPDATE tmpTable SET flag=1 WHERE tablename = tntmp and columnsname = tctmp;  
			set tntmp = "";	set tctmp = "";
			#选择一下条语句  
			SELECT tablename,columnsname into tntmp,tctmp FROM tmpTable WHERE flag = 0 limit 1;  
		END WHILE;  
end;  
call UpdateDataByColumnType("hb_dyrmyy");  
#如果存在 UpdateDataByColumnType 存储过程则删除 UpdateDataByColumnType 存储过程  
drop procedure if exists UpdateDataByColumnType;  
#如果存在 tmpTable 临时表则删除 UpdateDataByColumnType 临时表  
DROP TABLE if EXISTS tmpTable;