DELETEFROMtarget_tableWHEREtarget_table.columnIN(SELECTjoin_table.columnFROMjoin_tableWHEREjoin_table.condition ); target_table:需要删除数据的目标表。 join_table:用于连接的表,提供删除条件。 column:连接条件中的列。 condition:连接条件中的其他条件。 2. 示例 2.1 基本删除示例 假设有两个表:employees和de...
The DELETE statement in SQL uses the WHERE clause to specifically delete a record from the table. Example: CREATE TABLE customers (customer_id INT PRIMARY KEY,name VARCHAR(50),city VARCHAR(50),email VARCHAR(100));INSERT INTO customers (customer_id, name, city, email) VALUES(1, 'Sai', '...
This article describes how to delete table columns in SQL Server using SQL Server Management Studio (SSMS) or Transact-SQL.Babala When you delete a column from a table, the column and all the data it contains are deleted.LimitationsYou can't delete a column that has a CHECK constraint. ...
insert into employee (id,name,gender)values (null,'张飞',1,); insert into employee values (null,'关羽',1,'1998-08-08','1998-10-01','财神爷','老大的二弟'); insert into employee values (null,'刘备',0,'1990-01-01','公司的老大'),(null,'赵云',1,'2000-01-01','老大贴身人');...
有关详细信息,请参阅FROM (Transact-SQL)。 WHERE 指定用于限制删除行数的条件。 如果没有提供 WHERE 子句,则 DELETE 删除表中的所有行。 基于WHERE 子句中所指定的条件,有两种形式的删除操作: 搜索删除指定搜索条件以限定要删除的行。 例如,WHEREcolumn_name=value。
INSERT INTO course VALUES('03' , '英语' , '03'); --3条记录 SELECT count(1) FROM cours...
DELETE FROM my_table WHERE date_column < '2023-01-01'; 这条语句将删除my_table表中所有date_column小于2023-01-01的行。 全表删除 代码语言:txt 复制 DELETE FROM my_table; 这条语句将删除my_table表中的所有数据。 常见问题及解决方法 问题1:DELETE语句执行缓慢 ...
insert into 表名 values(值1,值2...) 这种插入数据行的的值必须与表的字段名一一对应,否则数据会插入失败给出错误提示: 错误提示:Column count doesn't match value count at row 1 第二种: insert into 表名(字段名,字段名...) values(值1,值2...) ...
INSERT [INTO] table_or_view_name (column_name[,…]) VALUES (expression)[,…] 向表中插入数据: 结果如下: 3.3 UPDATE语句 修改数据库中数据。语法如下: UPDATE table_or_view_name [FROM {}[,…]] SET column_name = expression | DEFAULT | NULL [,…] WHERE search_condition...
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...