"rows_to_scan": 3100, "access_type": "scan", "resulting_rows": 3100, "cost": 717, "chosen": true } ] }, "condition_filtering_pct": 100, "rows_for_plan": 3100, "cost_for_plan": 717, "chosen": true } ] }, { "attaching_conditions_to_tables": { "original_condition": "(...
#删除50w数据 mysql> delete from user limit 500000; Query OK, 500000 rows affected (3.70 sec) #分析表统计信息 mysql> analyze table user; +---+---+---+---+ | Table | Op | Msg_type | Msg_text | +---+---+---+---+ | test.user | analyze | status | OK | +---+---+...
#删除50w数据 mysql> delete from user limit500000; Query OK,500000rows affected (3.70sec) #分析表统计信息 mysql> analyze table user; +---+---+---+---+ | Table | Op | Msg_type | Msg_text | +---+---+---+---+ | test.user | analyze | status | OK | +---+---+---+...
DELETE FROM … WHERE 使用WHERE 子句删除指定的记录。 DELETE FROM departments WHERE department_name = 'Finance'; 1. 2. 如果省略 WHERE 子句,则表中的全部数据将被删除 DELETE FROM copy_emp; 1. 删除中的数据完整性错误 DELETE FROM departments WHERE department_id = 60; 1. 2. 多表删除例子 DELETE ...
The conditions in the optionalWHEREclause identify which rows to delete. With noWHEREclause, all rows are deleted. where_conditionis an expression that evaluates to true for each row to be deleted. It is specified as described inSection 13.2.9, “SELECT Statement”. ...
DELETE FROM somelog WHERE user = 'jcole' ORDER BY timestamp LIMIT 1 这将删除匹配 WHERE 子句的,并且最早被插入(通过 timestamp 来确定)的记录行。 DELETE 语句的LIMIT rows 选项是 MySQL 特有的,它告诉服务器在控制权被返回到客户端之前可被删除的最大记录行数目。这可以用来确保一个特定的 DELETE 命令...
DELETEFROMtable_name WHEREcondition; In this statement: First, specify the table from which you delete data. Second, use a condition to specify which rows to delete in theWHEREclause. If the row matches the condition, it will be deleted. ...
-> master_user='repl', -> master_password='123456', -> master_log_file='mysql-bin.000001', -> master_log_pos=977; Query OK, 0 rows affected, 2 warnings (0.00 sec) mysql> start slave; Query OK, 0 rows affected (0.01 sec) mysql> show slave status\G *** 1. row *** _IO_...
2.delete only two(2) rows for each 'country'. Example: MySQL DELETE rows using subqueries with alias and EXISTS A subquery can be used with MySQL DELETE statement. This is useful when you want to delete rows depending upon a complex condition. ...
某些关键字,如SELECT, DELETE或BIGINT,被保留,需要用作标识符,例如表和列名特殊待遇。内置函数的名称也可能如此。允许使用非保留关键字作为标识符而无需引用。 A ACCESSIBLE ® ACCOUNT ACTION ACTIVE; added in 8.0.14 (nonreserved) ADD ® ADMIN; became nonreserved in 8.0.12 AFTER AGAINST AGGREGATE ...