参考:http://www.ghugo.com/update-multiple-rows-with-different-values-and-a-single-sql-query/
update identities join deliveries on (UserID = Affiliate and World = Currency) set Balance = Balance + AffiliatePct where DeliveryID in (1,2,3,4) Subject Written By Posted Update from Multiple Rows Alan Little June 15, 2009 07:49AM ...
注意:执行的sql语句长度受到my.ini配置文件中max_allowed_packet参数的限制,所以当您使用本文的方法批量更新多条数据,超出sql语句长度限制时,请适当的修改该参数 本文参考自:http://www.ghugo.com/update-multiple-rows-with-different-values-and-a-single-sql-query/...
这样我们能轻松的在connection.query的回调函数中写执行完所有更新后的操作了,这种方式本质上是当有重复数据的时候先删除了原先记录并保留未更新字段,再进行插入,所以以上代码虽然只更新了3条语句,而affectedrows却有6行: 3,拼接update语句 mysql可以同时执行多条sql语句,如果我们将要执行的所有update语句拼成一条执行,...
TheWHERE clausedetermines which rows will be updated. It is an optional element of theUPDATEstatement. If theWHEREclause is omitted, all rows in the table will be updated. TheWHEREclause is so important that you should not forget. Sometimes, you may want to change just one row of the tabl...
TheUPDATEstatement is used to update existing data in tables. It can be used to change column values of a single row, a group of rows or all rows in a table. The following illustrates the MySQLUPDATEstatement syntax: UPDATE [LOW_ PRIORITY] [IGNORE] table_name [, table_name...] SET ...
32 Updating Multiple Rows mySQL 在参数中默认启动Safe Updates 模式,使得操作中不能通过一条指令来修改非PK多行。 Error Code: 1175. You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column To disable safe mode, toggle the option in Preferences ->...
A record lock is a lock on an index record. For example, SELECT c1 FROM t WHERE c1 = 10 FOR UPDATE; prevents any other transaction from inserting, updating, or deleting rows where the value of t.c1 is 10. 2.6.2 Gap Locks 间隙锁,间隙锁是在索引记录之间的间隙上的锁,即锁定一个区间。
To update multiple columns in a singleUPDATEstatement, we can use the following syntax: UPDATEusersSETname='Dave',age=45WHEREid=3; 1. 2. 3. This statement will update both thenameandagecolumns of the row withidequal to 3. Example 3: Updating All Rows ...
Written By Posted Update Multiple Rows with incrementing values Theo Tonge October 15, 2005 01:12PM Sorry, you can't reply to this topic. It has been closed. Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and ...