UPDATE mytable SET myfield = 'value' WHERE other_field = 'other_value'; 如果更新同一字段为同一个值,mysql也很简单,修改下where即可: UPDATE mytable SET myfield = 'value' WHERE other_field in ('other_values'); 这里注意 ‘other_values' 是一个逗号(,)分隔的字符串,如:1,2,3 那如果更新多...
INSERTINTOtable1(id,name)VALUES(1,'Alice'),(2,'Bob');INSERTINTOtable2(id,new_name)VALUES(1,'Lucy'),(2,'David'); 1. 2. 更新数据 UPDATEtable1SETname=(SELECTnew_nameFROMtable2WHEREtable2.id=table1.id)WHEREtable1.idIN(SELECTidFROMtable2); 1. 2. 3. 通过以上代码,我们成功将`table...
for_delete; Query OK, 3 rows affected (0.04 sec) mysql> insert for_delete (name) values ('D'); Query OK, 1 row affected (0.02 sec) mysql> select * from for_delete; +---+---+ | id | name | +---+---+ | 4 | D | +---+---+ 1 row in set (0.00 sec)截断表 trunca...
-- insert data for merits table INSERT INTO merits(performance,percentage) VALUES(1,0), (2,0.01), (3,0.03), (4,0.05), (5,0.08); -- insert data for employees table INSERT INTO employees(emp_name,performance,salary) VALUES('Mary Doe', 1, 50000), ('Cindy Minsu', 3, 65000), ('S...
在一次准备处理历史数据sql时,出现这么一个问题:You can't specify target table '表名' for update in FROM clause,大致的意思就是:不能在同一张表中先select再update。 在此进行一下复盘沉淀,使用测试sql复现当时的场景(mysql是8版本),准备测试数据: ...
---TRANSACTION 582122, ACTIVE 3874 sec insertingmysql tables in use 1, locked 1LOCK WAIT 2 lock struct(s), heap size 1136, 6 row lock(s)MySQL thread id 12529, OS thread handle 123145486712832, query id 94463 localhost root updateinsert into t_student values(5,"tom")Trx read view will ...
MySQL UPDATE Example Given below is a sample table created in MySQL. Schema Name:pacific Table Name:employees Column Names: empNum – Holds integer values for the employee number. lastName – Holds varchar values for the last name of the employee. ...
Table: t CreateTable:CREATETABLE`t` ( `id`int(11)NOTNULL, `num`int(11)DEFAULTNULL,PRIMARYKEY (`id`) ) ENGINE=InnoDBDEFAULTCHARSET=utf8 1 row in set (0.00 sec) mysql> select * from t; Empty set (0.00 sec) mysql> insert intot(id, num)values(1,100); ...
3、DROP TABLE:用于删除表及其结构,同时会永久性地删除表中的数据。在进行此操作之前,请确保备份了表中的数据。 UPDATE:用于更新表中的数据。可以使用UPDATE操作来更新单个或多个记录,也可以使用UPDATE语句来更新整张表。DROP TABLE操作会直接清理表和数据,执行速度较快,但可能导致无法找回表结构。在进行此操作之前...
I am trying to update and/or add rows to a datable, and although the records are changed in the datatable they are not updated in the database. I can update using sql commands, but I would rather update a row directly and then update the database. I had a look at Dan Carr's pos...