在SQL Server中使用REPLACE函数时,可以实现字符串替换的功能。REPLACE函数接受三个参数:原始字符串、要替换的子字符串和替换后的字符串。它会在原始字符串中查找所有匹配的子字符串,并将...
Convert the SELECT QUERY to an UPDATE All that's left to do now is to convert our SELECT query into an UPDATE. Having executed the query as a SELECT first, we can be confident that the UPDATE statement won't affect any other rows than the ones we're interested in. Here is the UPDAT...
> replace into users(user_id, user_name) values(1, 'cc'); Query OK, 2 rows affected (0.00 sec) 完成之后数据的情况如下:> select * from users; +---+---+ | user_id | user_name | +---+---+ | 1 | cc | | 2 | bb | +---+---+ 2 rows in set (0.00 sec)看来数据像...
+---+---+---+ 3 rows in set UPDATE语句的确按照预期更新了数据。 之后,使用REPLACE声明将洛杉矶市的人口更新为3696820。 REPLACE INTO cities(id,population) VALUES(2,3696820); Query OK, 2 rows affected 上面执行返回结果中提示:2 rows affected,说明有两行数据受影响。 最后,再次查询城市表的数据来验...
2 rows in set (0.00 sec) root@test 02:55:56>replace into yy values(1,'ccc'); Query OK, 2 rows affected (0.00 sec) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 如果本来已经存在的主键值,那么MySQL做update操作, ...
c3) values (4, 9); Query OK, 3 rows affected (0.04 sec) OceanBase (root@test)> select * from test_replace; +---+---+---+ | c1 | c2 | c3 | +---+---+---+ | 1 | 2 | 3 | | 4 | NULL | 9 | +---+---+---+ 2 rows in set (0.02 sec) 通过对比上面两个例...
in 是 ANY 的一种特殊情况: "in" equals "= any" [root@mysql.sock][dbt3_s1]> insert into t1 values(5); Query OK, 1 row affected (0.26 sec) [root@mysql.sock][dbt3_s1]> select a from t1wherea = ANY(select a from t2); ...
Query OK,2rowsaffected (0.01sec) xupeng@diggle7:3600(dba_m) [dba] mysql>SELECT*FROMauto;+---+---+---+---+|id|k|v|extra|+---+---+---+---+|2|2|2|extra2||3|3|3|extra3||4|1|1-1|NULL|+---+---+---+---+3rowsinset(0.00sec) xupeng@diggle7:3600(dba_m) [...
obclient>REPLACEINTOtestVALUES(3,'hello alibaba'),(2,'hello oceanbase');QueryOK,3rows affectedRecords:2Duplicates:1Warnings:0 查看test表中的行一、行二和行三的内容。 obclient>SELECT*FROMtest;+---+---+|c1|c2|+---+---+|1|hello alibaba||2|hello oceanbase||3|hello alibaba|+---+--...
公司开发人员在更新数据时使用了 replace into 语句,由于使用不当导致了数据的大量丢失,到底是如何导致的数据丢失?现分析如下。 二、问题分析 a. REPLACE 原理 REPLACE INTO 原理的官方解释为: REPLACE works exactly like INSERT, except that if an old row in the table has the same value as a new row ...