SQL操作中，查询是最复杂的，上面已经结束查询讲解，这里将介绍插入，更改删除

2 Insert

INSERT INTO TableName [ (columnList) ]VALUES (dataValueList)

举个例子大家就懂了
Insert a new row into Staff table supplying data for all columns.

• INSERT INTO Staff VALUES (‘SG16’, ‘Alan’, ‘Brown’, ‘Assistant’, ‘M’, Date‘1957-05-25’, 8300, ‘B003’);

  
  
  

  上面是用的默认值，其实亦可如下更改

• INSERT INTO Staff (staffNo, fName, lName,position, salary, branchNo)VALUES (‘SG44’, ‘Anne’, ‘Jones’,‘Assistant’, 8100, ‘B003’);
  – Or
• INSERT INTO Staff VALUES (‘SG44’, ‘Anne’, ‘Jones’, ‘Assistant’, NULL, NULL, 8100, ‘B003’);

其实，values处也可以用select，也就是向表格插入一个关系

3 Update

UPDATE TableName SET columnName1 = dataValue1[, columnName2 = dataValue2...][WHERE searchCondition]

依旧给几个例子

1. Give all staff a 3% pay increase.
   UPDATE Staff SET salary = salary*1.03;
2. Give all Managers a 5% pay increase.
   UPDATE Staff SET salary = salary*1.05 WHERE position = ‘Manager’;
3. (staffNo=‘SG14’) to Manager and change his salary to £18,000.
   UPDATE Staff SET position = ‘Manager’, salary = 18000 WHERE staffNo = ‘SG14’;

4 Delete

DELETE FROM TableName [WHERE searchCondition]

这个删除就很简单了

• Delete all viewings that relate to property PG4.
  DELETE FROM Viewing WHERE propertyNo = ‘PG4’;

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今天是对第五章SQL操作的收尾，sql并不难，上手后会发现很容易，很灵活，多练习才是硬道理