SQL DELETE查询用于从表中删除现有记录.
您可以将WHERE子句与DELETE查询一起使用来删除所选行，否则所有记录都将删除删除.
带WHERE子句的DELETE查询的基本语法如下 :
DELETE FROM table_name WHERE [condition];
您可以使用AND或OR运算符组合N个条件.
考虑具有以下记录的CUSTOMERS表 :
+----+----------+-----+-----------+----------+ | ID | NAME | AGE | ADDRESS | SALARY | +----+----------+-----+-----------+----------+ | 1 | Ramesh | 32 | Ahmedabad | 2000.00 | | 2 | Khilan | 25 | Delhi | 1500.00 | | 3 | kaushik | 23 | Kota | 2000.00 | | 4 | Chaitali | 25 | Mumbai | 6500.00 | | 5 | Hardik | 27 | Bhopal | 8500.00 | | 6 | Komal | 22 | MP | 4500.00 | | 7 | Muffy | 24 | Indore | 10000.00 | +----+----------+-----+-----------+----------+
以下代码有一个查询，它将删除一个ID为6的客户.
SQL> DELETE FROM CUSTOMERS WHERE ID = 6;
现在，CUSTOMERS表将有以下记录.
+----+----------+-----+-----------+----------+ | ID | NAME | AGE | ADDRESS | SALARY | +----+----------+-----+-----------+----------+ | 1 | Ramesh | 32 | Ahmedabad | 2000.00 | | 2 | Khilan | 25 | Delhi | 1500.00 | | 3 | kaushik | 23 | Kota | 2000.00 | | 4 | Chaitali | 25 | Mumbai | 6500.00 | | 5 | Hardik | 27 | Bhopal | 8500.00 | | 7 | Muffy | 24 | Indore | 10000.00 | +----+----------+-----+-----------+----------+
如果要删除CUSTOMERS表中的所有记录，则不需要使用WHERE子句，DELETE查询将如下所示;
SQL> DELETE FROM CUSTOMERS;
现在，CUSTOMERS表没有任何记录.
