MySQL数据表所有操作命令
mysql> select * from stu_test where xingming='dadou';+----+----------+-----+------+
| id | xingming | age | dept |
+----+----------+-----+------+
|3 |dadou |20 | nv|
+----+----------+-----+------+
1 row in set (0.00 sec)
mysql> select xingming,age from stu_test;
+----------+-----+
| xingming | age |
+----------+-----+
| laowang |28 |
| huasheng | 23 |
| dadou |20 |
+----------+-----+
3 rows in set (0.00 sec)
+----+----------+-----+------+
| id | xingming | age | dept |
+----+----------+-----+------+
|1 |laowang|28 | male |
|2 |huasheng |23 | male |
|3 |dadou |20 | nv|
|4 |dadou |20 | male |
+----+----------+-----+------+
4 rows in set (0.00 sec)
mysql> select 20 from stu_test;
+----+
| 20 |
+----+
| 20 |
| 20 |
| 20 |
| 20 |
+----+
4 rows in set (0.00 sec)
mysql> select distinct20 from stu_test;
+----+
| 20 |
+----+
| 20 |
+----+
1 row in set (0.00 sec)
mysql> select xingming,(age+dept) from stu_test;
+----------+------------+
| xingming | (age+dept) |
+----------+------------+
| laowang | 28 |
| huasheng | 23 |
| dadou | 20 |
| dadou | 20 |
+----------+------------+
4 rows in set, 3 warnings (0.01 sec)
mysql> selectxingming,(age+dept)+10 from stu_test; #在上面的基础上加10
+----------+---------------+
| xingming | (age+dept)+10 |
+----------+---------------+
| laowang | 38 |
| huasheng | 33 |
| dadou | 30 |
| dadou | 30 |
+----------+---------------+
4 rows in set, 3 warnings (0.00 sec)
小结：
select * from student where name='王五';
select name,english from student;
select distinct english from student;
select name,(chinese+english+math) fromstudent;
select name,(chinese+english+math)+10 fromstudent;
select name as 姓名,(chinese+english+math)+10 as 总分 from student;//别名
select name 姓名,(chinese+english+math)+10总分 from student;
select * from student whereenglish>'90';
select name from student where(chinese+english+math)>200;
select name from student where(chinese+english+math)> '200'//这里用单引号也是可以的
select name from student whereenglish>80 and english
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