一:添加数据
1.准备工作,和以前一样,要先使用一个数据库,并添加一张数据表,具体操作如下:
1)使用数据库
mysql> USE itcsat;
Database changed
Database changed
2)创建数据表
mysql> CREATE TABLE student
-> (
-> id INT(5),
-> name CHAR(20)NOT NULL,
-> sex CHAR(5),
-> grade FLOAT(5)
-> );
Query OK, 0 rows affected
-> (
-> id INT(5),
-> name CHAR(20)NOT NULL,
-> sex CHAR(5),
-> grade FLOAT(5)
-> );
Query OK, 0 rows affected
3)查看数据表是否存在
mysql> SHOW TABLES;
+------------------+
| Tables_in_itcsat |
+------------------+
| student |
+------------------+
1 row in set
+------------------+
| Tables_in_itcsat |
+------------------+
| student |
+------------------+
1 row in set
4)查看数据表信息 (两种方法)
mysql> SHOW CREATE TABLE student;
+---------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+---------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| student | CREATE TABLE `student` (
`id` int(5) DEFAULT NULL,
`name` char(20) NOT NULL,
`sex` char(5) DEFAULT NULL,
`grade` float DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=gbk |
+---------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set
+---------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+---------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| student | CREATE TABLE `student` (
`id` int(5) DEFAULT NULL,
`name` char(20) NOT NULL,
`sex` char(5) DEFAULT NULL,
`grade` float DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=gbk |
+---------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set
mysql> DESC student;//查看的是表格的具体信息
+-------+----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+-------+
| id | int(5) | YES | | NULL | |
| name | char(20) | NO | | NULL | |
| sex | char(5) | YES | | NULL | |
| grade | float | YES | | NULL | |
+-------+----------+------+-----+---------+-------+
4 rows in set
+-------+----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+-------+
| id | int(5) | YES | | NULL | |
| name | char(20) | NO | | NULL | |
| sex | char(5) | YES | | NULL | |
| grade | float | YES | | NULL | |
+-------+----------+------+-----+---------+-------+
4 rows in set
2.1第一种添加数据的方法
eg1:
INSERT INTO student(id,name,sex,grade)VALUES(1,"张三","男",89);
Query OK, 1 row affected
Query OK, 1 row affected
查看数据是否添加成功:SELECT *FROM student;
mysql> SELECT *FROM student;
+----+------+-----+-------+
| id | name | sex | grade |
+----+------+-----+-------+
| 1 | 张三 | 男 | 89 |
+----+------+-----+-------+
1 row in set
+----+------+-----+-------+
| id | name | sex | grade |
+----+------+-----+-------+
| 1 | 张三 | 男 | 89 |
+----+------+-----+-------+
1 row in set
注意:可以改变字段名的顺序,但是值也要相应改变,字段名必须和值相对应
eg2:
mysql> INSERT INTO student(name,id,grade,sex)VALUES("李四",2,80,"男");
Query OK, 1 row affected
Query OK, 1 row affected
mysql> SELECT *FROM student;
+----+------+-----+-------+
| id | name | sex | grade |
+----+------+-----+-------+
| 1 | 张三 | 男 | 89 |
| 2 | 李四 | 男 | 80 |
+----+------+-----+-------+
2 rows in set
+----+------+-----+-------+
| id | name | sex | grade |
+----+------+-----+-------+
| 1 | 张三 | 男 | 89 |
| 2 | 李四 | 男 | 80 |
+----+------+-----+-------+
2 rows in set
2.2第二种添加方法 //可以没有字段名,这样的话就和你建立的数据表的字段名一致
eg3:
mysql> INSERT INTO student VALUES(3,"王二","男",98);
Query OK, 1 row affected
Query OK, 1 row affected
mysql> SELECT *FROM student;
+----+------+-----+-------+
| id | name | sex | grade |
+----+------+-----+-------+
| 1 | 张三 | 男 | 89 |
| 2 | 李四 | 男 | 80 |
| 3 | 王二 | 男 | 98 |
+----+------+-----+-------+
3 rows in set
+----+------+-----+-------+
| id | name | sex | grade |
+----+------+-----+-------+
| 1 | 张三 | 男 | 89 |
| 2 | 李四 | 男 | 80 |
| 3 | 王二 | 男 | 98 |
+----+------+-----+-------+
3 rows in set
2.3第三种添加方法 //字段可以不全部添加完,只添加其中几个
eg4:
mysql> INSERT INTO student(id,name,grade)VALUES(4,"麻子",89);
Query OK, 1 row affected
Query OK, 1 row affected
mysql> SELECT * FROM student;
+----+------+------+-------+
| id | name | sex | grade |
+----+------+------+-------+
| 1 | 张三 | 男 | 89 |
| 2 | 李四 | 男 | 80 |
| 3 | 王二 | 男 | 98 |
| 4 | 麻子 | NULL | 89 |
+----+------+------+-------+
4 rows in set
+----+------+------+-------+
| id | name | sex | grade |
+----+------+------+-------+
| 1 | 张三 | 男 | 89 |
| 2 | 李四 | 男 | 80 |
| 3 | 王二 | 男 | 98 |
| 4 | 麻子 | NULL | 89 |
+----+------+------+-------+
4 rows in set
eg5:
mysql> INSERT INTO student(id,sex,grade)VALUES(5,"男",78);
Query OK, 1 row affected
Query OK, 1 row affected
mysql> SELECT *FROM student;
+----+------+------+-------+
| id | name | sex | grade |
+----+------+------+-------+
| 1 | 张三 | 男 | 89 |
| 2 | 李四 | 男 | 80 |
| 3 | 王二 | 男 | 98 |
| 4 | 麻子 | NULL | 89 |
| 5 | | 男 | 78 |
+----+------+------+-------+
5 rows in set
+----+------+------+-------+
| id | name | sex | grade |
+----+------+------+-------+
| 1 | 张三 | 男 | 89 |
| 2 | 李四 | 男 | 80 |
| 3 | 王二 | 男 | 98 |
| 4 | 麻子 | NULL | 89 |
| 5 | | 男 | 78 |
+----+------+------+-------+
5 rows in set