/usr/bin/envperluse strict; use warnings FATAL =>'all'; use Getopt::Long; my ( $command, $ssh_user, $orig_master_host, $orig_master_ip, $orig_master_port, $new_master_host, $new_master_ip, $new_master_port ); my $vip ='192.168.2.88'; my $ssh_start_vip ="/etc/init.d/k...
计算input_expression,然后按指定顺序对每个 WHEN 子句的 input_expression = when_expression 进行计算。 返回第一个取值为 TRUE 的 (input_expression = when_expression) 的 result_expression。 如果没有取值为 TRUE 的 input_expression = when_expression,则当指定 ELSE 子句时 SQL Server 将返回 else_result_...
select concat_ws('_',Sno,Sname) from Students.Student order by Sno desc limit 1 into @p; 报错2:Error Code: 1442. Can't update table 'student' in stored function/trigger because it is already used by statement which invoked this stored function/trigger. 原因:存储的函数或触发器不能修改已...
You may find theMySQL User Forumshelpful when working with triggers. For answers to commonly asked questions regarding triggers in MySQL, seeSection A.5, “MySQL 8.4 FAQ: Triggers”. There are some restrictions on the use of triggers; seeSection 27.8, “Restrictions on Stored Programs”. ...
触发器要用CREATE TRIGGER语句来创建。在触发器的定义里需要表明它将由哪种语句(INSERT、UPDATE或DELETE)触发,是在数据行被修改之前还是之后被触发。触发器创建语句的基本语法如下所示: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 CREATETRIGGERtrigger_ name # the trigger name{BEFORE|AFTER}# when the ...
错误号:1218; 符号: ER_CONNECT_TO_MASTER; SQLSTATE: 08S01 消息:连接到主服务器时出错:%s 错误号:1220; 符号: ER_ERROR_WHEN_EXECUTING_COMMAND; SQLSTATE:HY000 消息:执行命令%s时出错:%s 错误号:1221; 符号: ER_WRONG_USAGE; SQLSTATE: HY000 ...
Using GRANT to create users. Instead, use CREATE USER. Following this practice makes the NO_AUTO_CREATE_USER SQL mode immaterial for GRANT statements, so it too is removed, and an error now is written to the server log when the presence of this value for the sql_mode option in the opti...
dd::Event_impl, dd::Function_impl, dd::Library_impl, dd::Procedure_impl, dd::Routine, dd::Routine_impl, dd::Schema, dd::Schema_impl, dd::Spatial_reference_system, dd::Spatial_reference_system_impl, dd::Table_impl, dd::Trigger, dd::Trigger_impl, dd::View_impl, TABLE, thread_stat...
Triggers are often used to maintain the integrity of data across tables of an application. When a user on a website makes a purchase, for example, the first action that occurs in the database may be that a credit is inserted into an accounting table. ...
在MySQL官方文档中关于load data是这么描述的:When loading a table from a text file, use LOAD DATA. This is usually 20 times faster than using INSERT statements。load data的导入比insert快20倍,虽然实际中可能很难达到这个效率,但是对于MyDumper/MyLoader来说,使用--load-data选项,对导入速度的提升是显而...