delete from table where

"delete from" 是 SQL 语句中的删除命令，表示从指定的数据表中删除数据。

"table" 是数据表的名称。

"where" 是 SQL 语句中的过滤条件，用于确定哪些记录应该被删除。

例如：

"DELETE FROM customers WHERE last_name='Smith';"

这条语句将会删除客户表中所有 last_name 为 Smith 的记录。

相关问题

sqlserver delete where existis

To delete rows from a table based on the existence of data in another table, you can use the following SQL query:

DELETE FROM table1
WHERE EXISTS (
  SELECT 1 FROM table2
  WHERE table1.column_name = table2.column_name
)

This query will delete all rows from `table1` where there exists a matching row in `table2` based on the specified column name(s). You can modify the column names and table names as needed for your specific scenario.

oracle delete

DELETE command in Oracle is used to delete one or more rows from a table. The syntax for the DELETE command is as follows:

DELETE FROM table_name
WHERE condition;

Here, table_name is the name of the table from which you want to delete rows, and condition is the condition that specifies which rows to delete.

For example, to delete all rows from a table named employees where the employee_id is 100, you would use the following command:

DELETE FROM employees
WHERE employee_id = 100;

Note that the WHERE clause is optional. If you do not specify a WHERE clause, all rows in the table will be deleted.

Also, be careful when using the DELETE command, as it permanently removes data from the table. It is recommended to take a backup of the table or create a copy of the table before performing a DELETE operation.