Skip to content

Commit

Permalink
MySQL学习(一)：建库、建表、插入、修改、删除
Browse files Browse the repository at this point in the history
  • Loading branch information
@leo-qi
leo-qi committed Mar 14, 2017
1 parent a6c1fe1 commit 415b26e
Showing 1 changed file with 51 additions and 52 deletions.
103 changes: 51 additions & 52 deletions _posts/2017-03-02-SQL-1.markdown → _posts/2017-03-12-SQL-1.markdown
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ tags:
2. 建立了数据再建立，则：
```sql
mysql> create database test1;
ERROR 1007 (HY000): Can't create database 'test1'; database exists
ERROR 1007 (HY000): Can not create database 'test1'; database exists
```

3. 显示数据库信息：
Expand Down Expand Up @@ -80,14 +80,13 @@ tags:
mysql> show create table emp \G;
*************************** 1.row ***************************
Table: emp
Create Table: CREATE TABLE `emp` (
`ename` varchar(10) DEFAULT NULL,
`hiredate` date DEFAULT NULL,
`sal` decimal(10,2) DEFAULT NULL,
`deptno` int(2) DEFAULT NULL
Create Table: CREATE TABLE 'emp' (
'ename' varchar(10) DEFAULT NULL,
'hiredate' date DEFAULT NULL,
'sal' decimal(10,2) DEFAULT NULL,
'deptno' int(2) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
1 row in set (0.00 sec)
ERROR:
No query specified
```
Expand All @@ -102,7 +101,7 @@ tags:
```sql
mysql> create table emp(ename varchar(10), hiredate date , sal decimal(10,2), deptno int(2));
Query OK, 0 rows affected (0.03 sec)
.
mysql> desc emp;
+----------+---------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
Expand All @@ -113,11 +112,11 @@ tags:
| deptno | int(2) | YES | | NULL | |
+----------+---------------+------+-----+---------+-------+
4 rows in set (0.00 sec)
.
mysql> alter table emp modify ename varchar(20);
Query OK, 0 rows affected (0.05 sec)
Records: 0 Duplicates: 0 Warnings: 0
.
mysql> desc emp;
+----------+---------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
Expand All @@ -128,11 +127,11 @@ tags:
| deptno | int(2) | YES | | NULL | |
+----------+---------------+------+-----+---------+-------+
4 rows in set (0.00 sec)
.
mysql> alter table emp add column age int(3);
Query OK, 0 rows affected (0.06 sec)
Records: 0 Duplicates: 0 Warnings: 0
.
mysql> desc emp;
+----------+---------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
Expand All @@ -144,11 +143,11 @@ tags:
| age | int(3) | YES | | NULL | |
+----------+---------------+------+-----+---------+-------+
5 rows in set (0.00 sec)
.
mysql> alter table emp drop column age;
Query OK, 0 rows affected (0.06 sec)
Records: 0 Duplicates: 0 Warnings: 0
.
mysql> desc emp;
+----------+---------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
Expand All @@ -158,13 +157,13 @@ tags:
| sal | decimal(10,2) | YES | | NULL | |
+----------+---------------+------+-----+---------+-------+
3 rows in set (0.00 sec)
.
mysql> alter table emp change age age1 int(4);
ERROR 1054 (42S22): Unknown column 'age' in 'emp'
mysql> alter table emp change sal sal_salart int(4);
Query OK, 0 rows affected (0.04 sec)
Records: 0 Duplicates: 0 Warnings: 0
.
mysql> desc emp;
+------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
Expand All @@ -181,11 +180,11 @@ tags:
mysql> alter table emp add birth date after ename;
Query OK, 0 rows affected (0.05 sec)
Records: 0 Duplicates: 0 Warnings: 0
.
mysql> alter table emp add testColumn date after ename;
Query OK, 0 rows affected (0.08 sec)
Records: 0 Duplicates: 0 Warnings: 0
.
mysql> desc emp;
+------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
Expand All @@ -197,11 +196,11 @@ tags:
| sal_salart | int(4) | YES | | NULL | |
+------------+-------------+------+-----+---------+-------+
5 rows in set (0.00 sec)
.
mysql> alter table emp modify sal_salart int(5) first;
Query OK, 0 rows affected (0.06 sec)
Records: 0 Duplicates: 0 Warnings: 0
.
mysql> desc emp;
+------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
Expand All @@ -213,7 +212,7 @@ tags:
| hiredate | date | YES | | NULL | |
+------------+-------------+------+-----+---------+-------+
5 rows in set (0.00 sec)
.
mysql> alter table emp rename emp_test;
Query OK, 0 rows affected (0.01 sec)
```
Expand All @@ -223,7 +222,7 @@ tags:
mysql> alter table emp_test add column age int(3);
Query OK, 0 rows affected (0.05 sec)
Records: 0 Duplicates: 0 Warnings: 0
.
mysql> desc emp_test;
+------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
Expand All @@ -245,24 +244,24 @@ tags:
mysql> use test1;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
.
Database changed
.
mysql> insert into test(ename,age) values('abc',3);
Query OK, 1 row affected (0.01 sec)
.
mysql> select * from test;
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
+------------+-------+------------+-------+----------+------+
| NULL | abc | NULL | NULL | NULL | 3 |
+------------+-------+------------+-------+----------+------+
1 row in set (0.00 sec)
.
mysql> insert into test(ename,age) values('abc',3),('def',9);
Query OK, 2 rows affected (0.01 sec)
Records: 2 Duplicates: 0 Warnings: 0
.
mysql> select * from test;
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
Expand All @@ -279,7 +278,7 @@ tags:
mysql> update test set age = 8 where ename = 'def';
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
.
mysql> select * from test;
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
Expand All @@ -289,11 +288,11 @@ tags:
| NULL | def | NULL | NULL | NULL | 8 |
+------------+-------+------------+-------+----------+------+
3 rows in set (0.00 sec)
.
mysql> update test set age = 8 where ename = 'def22222222';
Query OK, 0 rows affected (0.01 sec)
Rows matched: 0 Changed: 0 Warnings: 0
.
mysql> select * from test;
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
Expand All @@ -303,11 +302,11 @@ tags:
| NULL | def | NULL | NULL | NULL | 8 |
+------------+-------+------------+-------+----------+------+
3 rows in set (0.00 sec)
.
mysql> update test set age = 81 where ename = 'def22222222';
Query OK, 0 rows affected (0.01 sec)
Rows matched: 0 Changed: 0 Warnings: 0
.
mysql> select * from test;
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
Expand All @@ -317,11 +316,11 @@ tags:
| NULL | def | NULL | NULL | NULL | 8 |
+------------+-------+------------+-------+----------+------+
3 rows in set (0.00 sec)
.
mysql> update test set age = 81 where ename = 'def';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
.
mysql> select * from test;
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
Expand All @@ -337,19 +336,19 @@ tags:
```sql
mysql> delete from test where age = 3;
Query OK, 2 rows affected (0.00 sec)
.
mysql> select * from test;
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
+------------+-------+------------+-------+----------+------+
| NULL | def | NULL | NULL | NULL | 81 |
+------------+-------+------------+-------+----------+------+
1 row in set (0.00 sec)
.
mysql> insert test(ename,age) values ('aaaaa',3),('aaaaa',5),('ccccc',3), ('aaaaa',9), ('ttttt',2);
Query OK, 5 rows affected (0.01 sec)
Records: 5 Duplicates: 0 Warnings: 0
.
mysql> select * from test;
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
Expand All @@ -368,7 +367,7 @@ tags:
```sql
mysql> alter table test rename test_col;
Query OK, 0 rows affected (0.01 sec)
.
mysql> select * from test_col;
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
Expand All @@ -381,10 +380,10 @@ tags:
| NULL | ttttt | NULL | NULL | NULL | 2 |
+------------+-------+------------+-------+----------+------+
6 rows in set (0.00 sec)
.
mysql> alter table test_col rename test;
Query OK, 0 rows affected (0.01 sec)
.
mysql> select * from test;
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
Expand All @@ -397,7 +396,7 @@ tags:
| NULL | ttttt | NULL | NULL | NULL | 2 |
+------------+-------+------------+-------+----------+------+
6 rows in set (0.00 sec)
.
mysql> selecdt distinct ename from test;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'selecdt distinct ename from test' at line 1
mysql> select distinct ename from test;
Expand All @@ -410,7 +409,7 @@ tags:
| ttttt |
+-------+
4 rows in set (0.00 sec)
.
mysql> select * from test where ename = 'aaaaa';
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
Expand All @@ -420,7 +419,7 @@ tags:
| NULL | aaaaa | NULL | NULL | NULL | 9 |
+------------+-------+------------+-------+----------+------+
3 rows in set (0.00 sec)
.
mysql> select * from test where age < 8;
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
Expand All @@ -431,7 +430,7 @@ tags:
| NULL | ttttt | NULL | NULL | NULL | 2 |
+------------+-------+------------+-------+----------+------+
4 rows in set (0.00 sec)
.
mysql> select * from test order by age;
+------------+-------+------------+-------+----------+------+
| sal_salart | ename | testColumn | birth | hiredate | age |
Expand All @@ -444,15 +443,15 @@ tags:
| NULL | def | NULL | NULL | NULL | 81 |
+------------+-------+------------+-------+----------+------+
6 rows in set (0.00 sec)
.
mysql> alter table test add column salart int (11);
Query OK, 6 rows affected (0.06 sec)
Records: 6 Duplicates: 0 Warnings: 0
.
mysql> alter table test change salart salary int (11);
Query OK, 6 rows affected (0.05 sec)
Records: 6 Duplicates: 0 Warnings: 0
.
mysql> select * from test;
+------------+-------+------------+-------+----------+------+--------+
| sal_salart | ename | testColumn | birth | hiredate | age | salary |
Expand All @@ -465,13 +464,13 @@ tags:
| NULL | ttttt | NULL | NULL | NULL | 2 | NULL |
+------------+-------+------------+-------+----------+------+--------+
6 rows in set (0.00 sec)
.
mysql> insert into test(ename,age,salary) values ('newNane1',1,100),
-> ('newName2',3,80),
-> ('newName3',5,10);
Query OK, 3 rows affected (0.01 sec)
Records: 3 Duplicates: 0 Warnings: 0
.
mysql> select * from test;
+------------+----------+------------+-------+----------+------+--------+
| sal_salart | ename | testColumn | birth | hiredate | age | salary |
Expand All @@ -487,7 +486,7 @@ tags:
| NULL | newName3 | NULL | NULL | NULL | 5 | 10 |
+------------+----------+------------+-------+----------+------+--------+
9 rows in set (0.00 sec)
.
mysql> select * from test order by salary;
+------------+----------+------------+-------+----------+------+--------+
| sal_salart | ename | testColumn | birth | hiredate | age | salary |
Expand All @@ -503,7 +502,7 @@ tags:
| NULL | newNane1 | NULL | NULL | NULL | 1 | 100 |
+------------+----------+------------+-------+----------+------+--------+
9 rows in set (0.00 sec)
.
mysql> select * from test order by salary limit 6,3;
+------------+----------+------------+-------+----------+------+--------+
| sal_salart | ename | testColumn | birth | hiredate | age | salary |
Expand Down

0 comments on commit 415b26e

Please sign in to comment.