Mysql 使用存储过程合并多个表数据
drop procedure if exists mergeTable;
CREATE PROCEDURE mergeTable()
BEGIN
#定义变量
declare temp_table_name varchar(20);
declare total int default 0;
declare done int default false;
#游标数据来源 查询出你想要合并的表名称
declare cur cursor for SELECT table_name
from information_schema.TABLES
where table_name LIKE '%user%'
group by table_name;
#定义标记结束
declare continue HANDLER for not found set done = true;
drop table if exists temp_table;
#创建临时表
CREATE temporary TABLE `temp_table`
(
`id` int(11) NOT NULL,
`name` int(11) NOT NULL,
`type` tinyint(2) NOT NULL
);
set total = 0;
open cur;
#变量赋值
fetch cur into temp_table_name;
while(not done)
do
#复制表数据到临时表
set @sqlStr = CONCAT('INSERT INTO temp_table (`id`, `name`, `type`)
SELECT `id`, `name`, `type`
FROM ', temp_table_name);
PREPARE stmt from @sqlStr;
#执行sql
EXECUTE stmt;
fetch cur into temp_table_name;
end while;
close cur;
#统计临时表个数
select count(1) from temp_table;
END;
#执行临时表
call mergeTable();编写mysql存储过程，循环的查询到表结构相同的多张表记录并将结果表合并输出。可以查询多天也可查询单天
直接实例代码与注释
CREATE PROCEDURE tableData1(in sTime VARCHAR(255),in eTime VARCHAR(255))
BEGIN #创建传入两个参数的存储过程，sTime开始时间，eTime结束时间
#定义变量
DECLARE date VARCHAR(255);
declare sqlVar varchar(21845);
declare rest int;
declare tableName varchar(1024);
#给初始值 sqlVar为空字符串,因为下边要拼接sql语句
set rest = 100;
set sqlVar='';
#当开始时间等于结束时间时，只拼接一次sql语句-实现可以只查询一天数据
if sTime = eTime THEN
SET date = DATE_FORMAT(sTime,"%Y-%m-%d");
set sqlVar=CONCAT(sqlVar," (SELECT *
FROM data_detail_",sTime," WHERE XXX
");
ELSE
#rest初始值是随便给的大于0的值。所以一定会进入循环。接下来在下边使用函数DATEDIFF用结束时间减去开始时间
#给rest重新赋值，当大于0时说明还没结束继续拼接sql，当等于或小于零时说明应该结束了，不需要继续往下拼接sql
while rest > 0 do
#转换日期格式，根据您自己的表结构来改，我是需要的
SET date = DATE_FORMAT(sTime,"%Y-%m-%d");
#使用开始时间拼接上字符串成为表名
set tableName=CONCAT('data_detail_',sTime);
#查询是否存在当前表名，赋值个数给cnt
select count(1) from information_schema.tables where table_name = tableName into @cnt;
#判断表名是否存在，当表不存在时直接跳过，不判断的话会报错
if @cnt != 0 then
#最最最重要的一点，当结束时间减去开始时间为1时，需要走else拼接上后边的的union all 。
#当结束时间减去开始时间为1时，说明已经到达结束时间的前一天，并且在最后DATE_ADD将前一天日期加1已经到达结束时间。最后不需要再拼接上一个union all
if rest=1 then
set sqlVar=CONCAT(sqlVar," (SELECT *
FROM data_detail_",sTime," WHERE XXX
)");
ELSE
set sqlVar=CONCAT(sqlVar," (SELECT
FROM data_detail_",sTime," WHERE XXX
)",' UNION all');
END IF;
END if;#判断到达某日期，当rest为1时说明已经到达结束日期前一天
set rest = DATEDIFF(eTime,sTime);
#当前日期加1
set sTime = DATE_FORMAT(DATE_ADD(sTime,INTERVAL 1 day),'%Y%m%d');
#结束循环与判断
END while;
END if;
#赋值用户变量
set @v_s=sqlVar;
#预定义sql语句
prepare stmt from @v_s;
#执行预定义sql语句
EXECUTE stmt;
#释放资源
DEALLOCATE PREPARE stmt;
end;
call tableData1(‘20211006’,‘20211008’);
结果长这个样子
1.创建存储过程语法:
CREATE PROCEDURE 存储过程名(参数列表)
BEGIN
存储过程体（一组合法的SQL语句）
END
2.变量的定义与赋值:
局部变量
DECLARE variable_name datatype(size) DEFAULT default_value;
DECLARE相当于关键字，有点类似var，表示定义一个变量；然后variable_name是你指定的变量名称；datatype表示数据类型而括号内的size表示对应类型的格式比如varchar(50)这样子，这里需要注意的是datatype只能是MySql支持的那些基本数据类型；DEFAULT关键字指明了变量的默认值为default_value。
通过SET赋值: SET variable_name = XXX
用户变量
用户变量不需要声明，可以直接使用，用户变量以@var_name的形式命名变量，变量名必须以@开头
赋值语法； set @varName=value;
只说了我用到的两种变量，其他变量查阅其他资料哦
3.While循环语句结构:
while(表达式) do
…
end while;
与其他语言while循环大同小异了其实，不难理解当表达式结果为false时退出循环
4.if判断语句:
IF expression THEN
statements;
ELSE
else-statements;
END IF;
5.union与union all 的区别
对重复结果的处理：UNION在进行表链接后会筛选掉重复的记录，Union All不会去除重复记录
需求： A库有多张按时间分表创建的表a_table_${date}，我想用定时器每天凌晨在B库创建一张和A库昨天的表一样的表b_table_${date}，然后将数据抓取过来,然后再对同步过来的表b_table_${date}做一次统计汇总插入到B库的另一张表b_table_statistic中。 使用存储过程做。可以根据统计时间传参来同步不同时间的数据。
思路：
1. 如果B库不存在统计日期的表b_table_${date}则创建一个新表b_table_${date}；
2. 开启事务，将B库表b_table_${date}的数据清空，方便失败了再次统计；
3. 将A库a_table_${date}表的数据同步到B库b_table_${date}表；
注意： 在插入的时候如果数据量比较大，可以通过分组进行批量插入来避免事务问题和mysql插入数据量限制问题；
4. 先删除B库b_table_statistic表中统计日期的数据；然后再向B库b_table_statistic表中插入统计日期的统计数据；
5. 关闭事务；
二. sql建模
三. 脚本
-- statistic_date 统计日期 接收yyyy-MM-dd类型的时间字符串
CREATE PROCEDURE create_current_day_cdr_table (IN statistic_date VARCHAR(64)) BEGIN
-- 同步t_cdr表记录需要插入的次数
DECLARE CDR_TABLE_INSERT_COUNT INT;
-- 声明事务
DECLARE EXIT HANDLER FOR SQLEXCEPTION, SQLWARNING ROLLBACK ;
-- 每次插入的记录数
SET @EACH_INSERT_SIZE = 1000;
-- 循环变量
SET @i = 1;
-- 根据统计日期拼接话单详情表名称
SET @tableName = CONCAT("t_cdr_", from_unixtime( unix_timestamp(statistic_date), '%Y%m%d') );
-- 如果统计日期的话单详情表不存在则创建
SET @createTableStr = CONCAT(" CREATE TABLE IF NOT EXISTS ", @tableName , "(
`id` int(11) NOT NULL AUTO_INCREMENT,
`call_type` char(2) DEFAULT NULL COMMENT '通话类型',
`cb_sessionid` varchar(64) DEFAULT NULL,
`busiprefix` varchar(16) DEFAULT NULL,
`caller_brand` varchar(64) DEFAULT NULL COMMENT '主叫品牌',
`caller` varchar(64) DEFAULT NULL COMMENT '主叫号码',
`calleraccess` varchar(64) DEFAULT NULL COMMENT '呼入主叫',
`callee_brand` varchar(64) DEFAULT NULL COMMENT '被叫品牌',
`callee` varchar(64) DEFAULT NULL COMMENT '被叫号码',
`calleeaccess` varchar(64) DEFAULT NULL COMMENT '呼入被叫',
`calleeoriginal` varchar(64) DEFAULT NULL COMMENT '被叫裸号',
`callerip` varchar(64) DEFAULT NULL COMMENT '主叫IP',
`in_gw_media_ip` varchar(64) DEFAULT NULL COMMENT '主叫媒体IP',
`in_gw_media_isp` int(11) DEFAULT NULL,
`callergatewayh323id` varchar(512) DEFAULT NULL COMMENT '主叫经由网关',
`callerproductid` varchar(64) DEFAULT NULL COMMENT '主叫设备',
`callertogateway` varchar(64) DEFAULT NULL COMMENT '呼出主叫',
`calleeip` varchar(64) DEFAULT NULL COMMENT '被叫信令IP',
`calleegatewayh323id` varchar(64) DEFAULT NULL COMMENT '被叫经由网关',
`calleeproductid` varchar(128) DEFAULT NULL COMMENT '被叫设备',
`calleetogateway` varchar(64) DEFAULT NULL COMMENT '呼出被叫',
`rtp_ip` varchar(64) DEFAULT NULL COMMENT '被叫媒体IP',
`gd_gw_media_isp` int(11) DEFAULT NULL,
`billingmode` char(1) DEFAULT NULL,
`calllevel` char(1) DEFAULT NULL,
`agentfeetime` int(11) DEFAULT NULL,
`starttime` datetime DEFAULT NULL COMMENT '起始时间',
`stoptime` datetime DEFAULT NULL COMMENT '结束时间',
`pdd` int(11) DEFAULT NULL COMMENT '接通延迟(秒)',
`linepdd` int(11) DEFAULT NULL,
`waittime` int(11) DEFAULT NULL COMMENT '接续时长(秒)',
`holdtime` int(11) DEFAULT NULL COMMENT '通话时长(秒)',
`feeprefix` varchar(64) DEFAULT NULL COMMENT '计费前缀',
`feetime` int(11) DEFAULT NULL COMMENT '计费时长(秒)',
`fee` bigint(20) unsigned DEFAULT NULL COMMENT '通话费用(元)',
`package_id` int(11) DEFAULT NULL,
`package_fee` bigint(20) unsigned DEFAULT NULL COMMENT '套餐费用(元)',
`package_feetime` int(11) DEFAULT NULL COMMENT '套餐时长(秒)',
`account` varchar(32) DEFAULT NULL COMMENT '账户号码',
`account_name` varchar(255) DEFAULT NULL COMMENT '账户名称',
`enddirection` char(1) DEFAULT NULL COMMENT '挂断方',
`endreason` varchar(255) DEFAULT NULL COMMENT '终止原因',
`agentpackagefee` bigint(20) unsigned DEFAULT NULL,
`agentpackagefeetime` int(11) DEFAULT NULL,
`agentpackageid` int(11) DEFAULT NULL,
`agentaccount` varchar(255) DEFAULT NULL,
`agentname` varchar(255) DEFAULT NULL,
`agentfee` bigint(20) unsigned DEFAULT NULL COMMENT '落地费用(元)',
`agentfeeprefix` varchar(64) DEFAULT '0',
`gatewayrouting_type` int(11) DEFAULT NULL,
`caller_area` varchar(32) DEFAULT NULL COMMENT '主叫地区',
`area_code` varchar(32) DEFAULT NULL COMMENT '被叫地区',
`province` varchar(64) DEFAULT NULL,
`city` varchar(64) DEFAULT NULL,
`switch` varchar(64) DEFAULT NULL COMMENT '主叫经由VLS-switch',
`operators` int(11) unsigned DEFAULT '0',
`outgw_area` varchar(64) DEFAULT NULL,
`ingw_type` varchar(32) DEFAULT NULL,
`routetrace` varchar(320) DEFAULT NULL COMMENT '路由跟踪',
`call_encode` varchar(200) DEFAULT NULL COMMENT '语音编码',
`fee_type` char(1) DEFAULT NULL COMMENT '费率类型',
`fee_type_ee` char(1) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `index_account` (`account`),
KEY `index_account_name` (`account_name`),
KEY `index_agentaccount` (`agentaccount`),
KEY `index_caller` (`caller`),
KEY `index_callee` (`callee`),
KEY `index_callergatewayh323id` (`callergatewayh323id`(64)),
KEY `index_calleegatewayh323id` (`calleegatewayh323id`),
KEY `index_starttime` (`starttime`),
KEY `index_callerproductid` (`callerproductid`),
KEY `index_calleeproductid` (`calleeproductid`),
KEY `index_city` (`city`),
KEY `index_call_type` (`call_type`),
KEY `index_stoptime` (`stoptime`)
)ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8");
PREPARE createtablestmt FROM @createTableStr;
EXECUTE createtablestmt;
-- 开启事务 注意： 必须要在建表语句下面 需要事务的地方进行 如果放在上面 则事务不起作用
START TRANSACTION ;
-- 如果统计日期的话单详情表存在数据则先删除
SET @delCDRTableStr = CONCAT( " DELETE FROM ", @tableName );
PREPARE delCDRTableStmt FROM @delCDRTableStr;
EXECUTE delCDRTableStmt;
-- 同步抓取vlsdbcdr库统计日期的话单详情表数据 由于表数据量较大，采取分批插入 将EXECUTE结果赋值到@CDRTableRowCount变量中
SET @countCDRTableStr = CONCAT( " SELECT COUNT(1) INTO @CDRTableRowCount FROM vlsdbcdr.", @tableName );
PREPARE countCDRTableStmt FROM @countCDRTableStr;
EXECUTE countCDRTableStmt;
-- 计算需要插入的次数
SELECT CEIL (@CDRTableRowCount / @EACH_INSERT_SIZE) INTO CDR_TABLE_INSERT_COUNT;
WHILE @i <= CDR_TABLE_INSERT_COUNT DO
SET @baseColumn = " `id`, `call_type`, `cb_sessionid`, `busiprefix`, `caller_brand`, `caller`, `calleraccess`, `callee_brand`, `callee`, `calleeaccess`, `calleeoriginal`,
`callerip`, `in_gw_media_ip`, `in_gw_media_isp`, `callergatewayh323id`, `callerproductid`, `callertogateway`, `calleeip`, `calleegatewayh323id`, `calleeproductid`,
`calleetogateway`, `rtp_ip`, `gd_gw_media_isp`, `billingmode`, `calllevel`, `agentfeetime`, `starttime`, `stoptime`, `pdd`, `linepdd`, `waittime`, `holdtime`,
`feeprefix`, `feetime`, `fee`, `package_id`, `package_fee`, `package_feetime`, `account`, `account_name`, `enddirection`, `endreason`, `agentpackagefee`,
`agentpackagefeetime`, `agentpackageid`, `agentaccount`, `agentname`, `agentfee`, `agentfeeprefix`, `gatewayrouting_type`, `caller_area`, `area_code`,
`province`, `city`, `switch`, `operators`, `outgw_area`, `ingw_type`, `routetrace`, `call_encode`, `fee_type`, `fee_type_ee` ";
SET @insertCDRStr = CONCAT(" INSERT INTO ", @tableName, "(", @baseColumn, ")", " SELECT ", @baseColumn, " FROM vlsdbcdr.", @tableName,
" LIMIT ", (@i - 1) * @EACH_INSERT_SIZE, ",", @EACH_INSERT_SIZE );
PREPARE insertCDRstmt FROM @insertCDRStr;
EXECUTE insertCDRstmt;
SET @i = @i + 1;
END WHILE;
-- 删除销售客户账单表已存在的统计日期数据
DELETE FROM t_sale_customer_day_cost WHERE statistical_time = statistic_date;
-- 向销售客户日账单表插入统计日期的数据
SET @insertSCDCStr = CONCAT( "
INSERT INTO osp.t_sale_customer_day_cost
( statistical_time, customer_id, account_id, service_type, fee_type, call_times, caller, caller_area, feetime, fee, create_time)
SELECT '", statistic_date,"' AS statistical_time, (SELECT out_id FROM t_account AS A WHERE A.account_id = CDR.account AND A.type = 0) AS customer_id,
CDR.account, '5', CDR.fee_type, count(1) AS call_count, CDR.caller, CDR.caller_area, SUM(CDR.feetime / 60), SUM(CDR.fee), NOW()
FROM ",
@tableName, " AS CDR
WHERE
CDR.call_type = '5'
GROUP BY
customer_id, CDR.account, CDR.call_type, CDR.fee_type ");
PREPARE insertSCDCstmt FROM @insertSCDCStr;
EXECUTE insertSCDCstmt;
-- 提交事务
COMMIT ;
END;
四 定时器代码
package com.yzx.osp.modular.task.controlller;
import com.yzx.osp.common.util.DateUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import java.util.Date;
/**
* @author yuanshushu
* @date 2018/9/13
* @description 话单详情定时任务类
*/
@Component
public class CdrDateTask {
@Autowired
private JdbcTemplate jdbcTemplate;
@Scheduled(cron = "0/10 * * * * ?")
public void syncTCdrDateData() {
try {
// 按日期生成话单详情表
this.jdbcTemplate.execute("call create_current_day_cdr_table()");
} catch (Exception e) {
e.printStackTrace();
}
}
}五. 存储过程DEMO 小
5.1 遍历分批插入
CREATE PROCEDURE test () BEGIN
DECLARE CDR_TABLE_ROW_COUNT BIGINT;
DECLARE CDR_TABLE_INSERT_COUNT INT;
-- 声明事务
DECLARE EXIT HANDLER FOR SQLEXCEPTION, SQLWARNING ROLLBACK ;
SET @EACH_INSERT_SIZE = 100;
SET @i = 1;
SELECT count(1) FROM t_cdr_20180811 INTO CDR_TABLE_ROW_COUNT;
SELECT CEIL (CDR_TABLE_ROW_COUNT / @EACH_INSERT_SIZE) INTO CDR_TABLE_INSERT_COUNT;
START TRANSACTION ;
WHILE @i <= CDR_TABLE_INSERT_COUNT DO
-- 拼接插入sql 注意： mysql limit m,n m为开始行数, n为查询行数
SET @insertStr = CONCAT( "
INSERT INTO t_cdr_20180812
(call_type, cb_sessionid)
SELECT
call_type, cb_sessionid
FROM
t_cdr_20180811
limit ", (@i - 1) * @EACH_INSERT_SIZE, ",", @EACH_INSERT_SIZE );
PREPARE insertStrStmt FROM @insertStr;
EXECUTE insertStrStmt;
SET @i = @i + 1;
END WHILE;
COMMIT ;
END; 5.2 获取EXECUTE执行结果
-- statistic_date 统计日期 接收yyyy-MM-dd类型的时间字符串
CREATE PROCEDURE create_current_day_cdr_table (IN statistic_date VARCHAR(64)) BEGIN
SET @tableName = 't_cdr_20180811';
SET @countCDRTableStr = CONCAT( " SELECT COUNT(1) INTO @STABLE_CDR_ROW_COUNT FROM vlsdbcdr.", @tableName);
PREPARE countCDRTableStmt FROM @countCDRTableStr;
EXECUTE countCDRTableStmt;
SELECT @STABLE_CDR_ROW_COUNT;
END;
案例
建立数据集
#创建表
create table orders1 (
orderid int(11) not null primary key ,
Itemid varchar(30) not null ,
category varchar(10) not null ,
orderdate datetime not null ,
sales float not null );#创建表
create table orders2 like orders1;
create table orders3 like orders1;
create table orders4 like orders1;
create table orders5 like orders1;
#插入数据
insert into orders1 (orderid, Itemid, category, orderdate, sales)
values ('1','k1','A','2020-1-2','459.5'),
('2','k2','A','2020-2-2','345.4'),
('3','k1','A','2020-1-7','47'),
('4','k3','C','2020-1-21','678'),
('5','k4','B','2020-5-2','345'),
('6','k5','C','2020-3-12','654'),
('7','k4','B','2020-4-25','464'),
('8','k2','A','2020-5-28','632'),
('9','k3','C','2020-7-20','98'),
('10','k5','C','2020-4-28','455.6'),
('11','k1','A','2020-3-27','459.7'),
('12','k2','A','2020-2-23','776.6'),
('13','k4','B','2020-2-12','759'),
('14','k5','C','2020-8-2','999'),
('15','k2','A','2020-9-21','599'),
('16','k3','C','2020-10-21','433'),
('17','k4','B','2020-10-28','232'),
('18','k5','C','2020-10-3','124'),
('19','k3','C','2020-6-6','321.4'),
('20','k4','B','2020-9-11','788.6');
insert into orders2 (orderid, Itemid, category, orderdate, sales)
values ('21','k1','A','2020-1-3','954.5'),
('22','k2','A','2020-2-4','435.4'),
('23','k1','A','2020-1-8','74'),
('24','k3','C','2020-7-5','78'),
('25','k4','B','2020-5-26','35'),
('26','k5','C','2020-3-10','54'),
('27','k4','B','2020-4-29','44'),
('28','k2','A','2020-5-24','32'),
('29','k3','C','2020-7-7','98'),
('30','k5','C','2020-4-6','45.6'),
('31','k1','A','2020-3-23','49.7'),
('32','k2','A','2020-2-1','76.6'),
('33','k4','B','2020-2-18','759'),
('34','k5','C','2020-8-29','99'),
('35','k2','A','2020-9-29','59'),
('36','k3','C','2020-10-25','43'),
('37','k4','B','2020-10-28','22'),
('38','k5','C','2020-10-3','14'),
('39','k3','C','2020-6-10','31.4'),
('40','k4','B','2020-9-11','78.6');
insert into orders3 (orderid, Itemid, category, orderdate, sales)
values ('41','k1','A','2020-1-3','954.5'),
('42','k2','A','2020-2-4','435.4'),
('43','k1','A','2020-1-8','674'),
('44','k3','C','2020-7-5','478'),
('45','k4','B','2020-5-26','635'),
('46','k5','C','2020-3-10','654'),
('47','k4','B','2020-4-29','644'),
('48','k2','A','2020-5-24','632'),
('49','k3','C','2020-7-7','98'),
('50','k5','C','2020-4-6','645.6'),
('51','k1','A','2020-3-23','49.7'),
('52','k2','A','2020-2-1','676.6'),
('53','k4','B','2020-2-18','759'),
('54','k5','C','2020-8-29','99'),
('55','k2','A','2020-9-29','459'),
('56','k3','C','2020-10-25','443'),
('57','k4','B','2020-10-28','522'),
('58','k5','C','2020-10-3','614'),
('59','k3','C','2020-6-10','31.4'),
('60','k4','B','2020-9-11','78.6');
insert into orders4 (orderid, Itemid, category, orderdate, sales)
values ('61','k1','A','2020-1-3','954.5'),
('62','k2','A','2020-2-4','4435.4'),
('63','k1','A','2020-1-8','874'),
('64','k3','C','2020-7-5','778'),
('65','k4','B','2020-5-26','535'),
('66','k5','C','2020-3-10','754'),
('67','k4','B','2020-4-29','644'),
('68','k2','A','2020-5-24','932'),
('69','k3','C','2020-7-7','898'),
('70','k5','C','2020-4-6','645.6'),
('71','k1','A','2020-3-23','449.7'),
('72','k2','A','2020-2-1','376.6'),
('73','k4','B','2020-2-18','759'),
('74','k5','C','2020-8-29','399'),
('75','k2','A','2020-9-29','159'),
('76','k3','C','2020-10-25','343'),
('77','k4','B','2020-10-28','222'),
('78','k5','C','2020-10-3','114'),
('79','k3','C','2020-6-10','231.4'),
('80','k4','B','2020-9-11','178.6');
insert into orders5 (orderid, Itemid, category, orderdate, sales)
values ('81','k1','A','2020-1-3','1954.5'),
('82','k2','A','2020-2-4','1435.4'),
('83','k1','A','2020-1-8','174'),
('84','k3','C','2020-7-5','178'),
('85','k4','B','2020-5-26','35'),
('86','k5','C','2020-3-10','154'),
('87','k4','B','2020-4-29','144'),
('88','k2','A','2020-5-24','132'),
('89','k3','C','2020-7-7','198'),
('90','k5','C','2020-4-6','145.6'),
('91','k1','A','2020-3-23','149.7'),
('92','k2','A','2020-2-1','176.6'),
('93','k4','B','2020-2-18','1759'),
('94','k5','C','2020-8-29','199'),
('95','k2','A','2020-9-29','159'),
('96','k3','C','2020-10-25','143'),
('97','k4','B','2020-10-28','122'),
('98','k5','C','2020-10-3','114'),
('99','k3','C','2020-6-10','131.4'),
('100','k4','B','2020-9-11','178.6');创建存储过程
创建一个表data来储存查询结果数据集
create table data (category varchar(10) not null ,orderid int(11) not null primary key ,
Itemid varchar(30) not null ,
sales float not null
);#如果你需要调试存储过程一定要加这句代码
drop procedure if exists insert_odata;
存储过程主体
delimiter ;;
create procedure insert_odata (IN i int)
begin
DECLARE i int;
set i=1;
while i<=5 do
set @sqlStr:=CONCAT('insert into data (select category, orderid,Itemid,sales from(
select category,orderid,Itemid,sales,
row_number()over(partition by category order by category,sales desc ) as ranking
from orders',i,') t1 where ranking <=2);');
prepare stmt from @sqlStr;
execute stmt;
deallocate prepare stmt;
set i=i+1;
end while
end
;;
delimiter ;调用存储过程，并查看数据结果
call insert_odata()
select * from data;
最后求所有数据每个category,sales的前两名
select category,orderid,Itemid,sales from
(select category,orderid,Itemid,sales,
row_number()over(partition by category,Itemid order by category,sales desc ) as ranking
from data) t1 where ranking <=2
);一点小拓展
我在第一次写的时候，因为不知道在MySQL中使用循环需要将其放入存储过程，我的思路是将表名作为变量创建存储过程，然后再通过循环调用存储过程，导致第一个方案用了两个存储过程。
create table data (category varchar(10) not null ,orderid int(11) not null primary key ,
Itemid varchar(30) not null ,
sales float not null
);
#第一个存储过程
#用表作为变量
drop procedure if exists insert_odata;
delimiter ;;
create procedure insert_odata (IN temp varchar(30))
begin
set @tempStr:=CONCAT('insert into data (select category,orderid,Itemid,sales from(
select category,orderid,Itemid,sales,
row_number()over(partition by category order by category,sales desc ) as ranking
from ',temp,') t1 where ranking <=2);');
prepare stmt from @tempStr;
execute stmt;
deallocate prepare stmt;
end
;;
delimiter ;#第二个 存储过程
drop procedure if exists run;
delimiter $$
create procedure run()
begin
DECLARE i int;
DECLARE Tname varchar(25);
set i=1;
while i<=5 do
set Tname =concat('orders',i);
call insert_odata(Tname);
set i=i+1;
end while;
end
$$delimiter ;
call run();
select * from data;
