测试性能:使用如下代码进行性能测试。 SETprofiling=1;DELETEFROMtable_nameWHEREidIN(1,2,3);SHOWPROFILES;SHOWPROFILEALLFORQUERY1; 1. 2. 3. 4. 执行删除操作: DELETEFROMtable_nameWHEREidIN(1,2,3); 1. 四、状态图 下面是解决"mysql delete in 性能问题"的状态图: 完成分析选择分批删除方式选择其他方...
mysql> select t1.a from t1 join t2 on t1.a = t2.a; +---+ | a | +---+ | 4 | +---+ 1 row in set (0.00 sec) mysql> select t1.a from t1 join t2 on t1.a = t2.a; +---+ | a | +---+ | 4 | +---+ 1 row in set (0.00 sec) 1. 2. 3. 4. 5. 6. ...
DELETE 语句: mysql> use RUNOOB; Database changed mysql> DELETE FROM runoob_tbl WHERE runoob_id=3; Query OK, 1 row affected (0.23 sec)使用PHP 脚本删除数据PHP 使用 mysqli_query() 函数来执行SQL语句,你可以在 DELETE 命令中使用或不使用 WHERE 子句。
I need to delete a row in mysql database. The condition values in the where clause is a varchar and contains hyphens. my query looks like: "DELETE from TestTable Where TestID = " + testid + ";"; The testid value containd hyphen (for ex: dis-connect) When i use like opera...
delete from tu where id in (3,4); Query OK, 2 rows affected (0.00 sec) ---TRANSACTION 146880, ACTIVE 1 sec 2 lock struct(s), heap size 360, 2 row lock(s), undo log entries 2 MySQL thread id 1, OS thread handle 0x7f61ab1c7700, query id 928 localhost msandbox cleaning up ...
mysql> insert into student(name,age) values('曾导','84'); Query OK, 1 row affected (0.00 sec) mysql> select * from student; +---+---+---+---+---+---+ | id | name | age | gender | cometime | birthday | +---+---+---+---+---+---+ | 1 | 邱导 | 78 |...
mysql>create tableundo_demo(->id int notnull,->key1varchar(100),->colvarchar(100),->primarykey(id),->keyidx_key1(key1)->);QueryOK,0rowsaffected(0.05sec) 表中id主键,key1是二级索引,col是普通列。我们前面说过每个表都有一个唯一的table id,在information_Shcema中的innodb_sys_tables。
mysql>create user'testuser01'@'%'identified by'Test01.~!#';QueryOK,0rowsaffected(0.01sec) 通过上面的例子发现,第一次创建用户testuser01之后,使用的drop的方式将用户删除,我们重新创建用户,正常创建用户成功,这时候大家会想这有啥问题吗?接着往下看, ...
PHP使用 mysqli_query() 函数来执行SQL语句, 你可以在 SQL DELETE 命令中使用或不使用 WHERE 子句。该函数与 mysql> 命令符执行SQL命令的效果是一样的。 MySQL DELETE 语句测试以下PHP实例将删除 runoon_tbl 表中 runoon_id 为 3 的记录: <?php$dbhost = ...
explain select b from aa where b in ('a','ab'); 可以得到如下的查询执行计划: test=# explain select b from aa where b in ('a','ab'); QUERY PLAN --- Bitmap Heap Scan on aa (cost=8.52..13.86 rows=2 width=38) Recheck Cond: ((b)::text = ANY (...