三、SQL基础-数据增删改
1.1 插入数据-insert
INSERT INTO table [(column [, column...])]
VALUES (value [, value...]);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,DEPTNO ) VALUES
( 7521, 'WARD', 'SALESMAN', 7698, '1981-02-22', 1250, 500, 30);
1.2 插入数据-向表中插入空值
INSERT INTO EMP
( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, DEPTNO ) VALUES
(7369, 'SMITH', 'CLERK', 7902, '1980-12-17', 800, 20);
INSERT INTO EMP
( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,DEPTNO ) VALUES
(7369, 'SMITH', 'CLERK', 7902, '1980-12-17', 800, NULL, 20);
1.3 插入数据-一次插入多行数据
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,DEPTNO ) VALUES
( 7369, 'SMITH', 'CLERK', 7902, '1980-12-17', 800, NULL, 20),
( 7499, 'ALLEN', 'SALESMAN', 7698, '1981-02-20', 1600, 300, 30);
1.4 插入数据-字段省略不写
INSERT INTO EMP VALUES
( 7566, 'JONES', 'MANAGER', 7839, '1981-04-02', 2975, NULL, 20);
1.5 插入数据-插入日期
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,DEPTNO ) VALUES ( 7654, 'MARTIN', 'SALESMAN', 7698, '1981-09-28', 1250, 1400, 30);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,DEPTNO ) VALUES ( 7698, 'BLAKE', 'MANAGER', 7839, str_to_date('1981-06-12','%Y-%m-%d'), 2850, NULL, 30);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,DEPTNO ) VALUES ( 7782, 'CLARK', 'MANAGER', 7839, now(), 2450, NULL, 10);
1.6 插入数据-表的复制
create table 表名 as select语句;
2.1 修改数据-update
update 表名 set 字段名 = 新值,字段名=新值,...where 筛选条件;
3.1 删除数据-delete
delete from 表名 where 筛选条件;
truncate table 表名;