if not exists (select 1 from table where id = 1) insert into table(id, update_time) values(1, getdate()) else update table set update_time = getdate() where id = 1 在MySQL 中也可以先select,判断是否...
本文实例总结了MySQL子查询操作。...INSERT INTO tbl1 values(1), (5), (13), (27); INSERT INTO tbl2 values(6), (14), (11), (20); any some关键字的子查询 SELECT num1 FROM tbl1 WHERE num1 > ANY (SELECT nu
INSERT INTO WEEK_INCOME SELECT '星期一',1000 UNION ALL SELECT '星期二',2000 UNION ALL SELECT '星期三',3000 UNION ALL SELECT '星期四',4000 UNION ALL SELECT '星期五',5000 UNION ALL SELECT '星期六',6000 ...
详解python中executemany和序列的使用方法 一 代码 import sqlite3 persons=[ ...conn.executemany(INSERT INTO person(firstname,lastname) VALUES(?,?),persons) for row in conn.execute(SELECT f
insert into Table(****) select **** where not exists(select 1 from Table where ****); 3.使用SERIALIZABLE隔离级别,并且使用updlock或者xlock锁提示(等效于在默认隔离级别下使用(updlock,holdlock)或(xlock,...
主库执行 CREATE DATABASE test CHARACTER SET utf8 COLLATE utf8_general_ci;...insert into test.h1 values(1,"wang"),(2,"guo"),(3,"yang"),(4,"he"); select * from test.h1; 从库测试 delete from test.h1 where
两个sql语句如下:(1)insert into backup_table select * from source_table(2)DELETE FROM source_table WHERE Id>5 AND titleWeight<32768 AND joinTime<‘$daysago_1week’teamUser表的表结构如下:...
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if not exists (select 1 from table where id = 1) insert into table(id, update_time) values(1, getdate()) else update table set update_time = getdate() where id = 1 在MySQL 中也可以先select,判断是否...
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本文实例总结了MySQL子查询操作。...INSERT INTO tbl1 values(1), (5), (13), (27); INSERT INTO tbl2 values(6), (14), (11), (20); any some关键字的子查询 SELECT num1 FROM tbl1 WHERE num1 > ANY (SELECT nu
INSERT INTO WEEK_INCOME SELECT '星期一',1000 UNION ALL SELECT '星期二',2000 UNION ALL SELECT '星期三',3000 UNION ALL SELECT '星期四',4000 UNION ALL SELECT '星期五',5000 UNION ALL SELECT '星期六',6000 ...
详解python中executemany和序列的使用方法 一 代码 import sqlite3 persons=[ ...conn.executemany(INSERT INTO person(firstname,lastname) VALUES(?,?),persons) for row in conn.execute(SELECT f
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两个sql语句如下:(1)insert into backup_table select * from source_table(2)DELETE FROM source_table WHERE Id>5 AND titleWeight<32768 AND joinTime<‘$daysago_1week’teamUser表的表结构如下:...
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