1.在工作会遇到这种情况,mysql数据库,系统涉及到备份多表数据,为了方便,用存储过程来实现此功能,同时也复习一下存储过程的写法,同时记录下方便以后扩展修改
2.存储过程代码如下
-- 创建存储过程
CREATE PROCEDURE test_01()
BEGIN
-- 定义变量
DECLARE s int DEFAULT 0;
DECLARE monitorTable varchar(255);
DECLARE countTable varchar(256);
DECLARE countTableNew varchar(256);
-- 定义游标,并将sql结果集赋值到游标中
DECLARE report CURSOR FOR select DISTINCT monitor_table,count_table from t_monitorinfo ;
-- 声明当游标遍历完后将标志变量置成某个值
DECLARE CONTINUE HANDLER FOR NOT FOUND SET s=1;
-- 打开游标
open report;
-- 将游标中的值赋值给变量,注意:变量名不要和返回的列名同名,变量顺序要和sql结果列的顺序一致
fetch report into monitorTable,countTable;
-- 当s不等于1,也就是未遍历完时,会一直循环
while s<>1 do
-- 执行业务逻辑
set countTableNew = concat(countTable,'_bak');
-- 表名是参数的语法
SET @STMT =CONCAT("CREATE TABLE ",countTableNew," LIKE ",countTable,";");
PREPARE STMT FROM @STMT;
EXECUTE STMT;
SET @STMT2 =CONCAT("INSERT INTO ",countTableNew," SELECT * FROM ",countTable,";");
PREPARE STMT2 FROM @STMT2;
EXECUTE STMT2;
-- 表名非参数的语法
-- update patrolreporthistory set reportUrl = CONCAT('patrolReport.html?monitorId=',substring(report_url,15,1),'&reportId=',report_id) where reportId=report_id;
-- 将游标中的值再赋值给变量,供下次循环使用
fetch report into monitorTable,countTable;
-- 当s等于1时表明遍历以完成,退出循环
end while;
-- 关闭游标
close report;
END;