1.语法错误：SQL syntax

[Err] 1064 - 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 '(`sno`,`con`,`degree`) values (109,'9-888',99)' at line 1

2.未知列：查看表中是否存在'con'该字段

[Err] 1054 - Unknown column 'con' in 'field list'

3.超过列的值的范围：'degree'列的长度超了

[Err] 1264 - Out of range value for column 'degree' at row 1

4.值数量与字段数量不匹配：

[Err] 1136 - Column count doesn't match value count at row 1

5.存在重复的主键值

[Err] 1062 - Duplicate entry '3-105' for key 'PRIMARY'

6.定义了多个主键

[Err] 1068 - Multiple primary key defined

7.该表已存在

[Err] 1050 - Table 'grade' already exists

8.找不到该表（该表不存在）

[Err] 1051 - Unknown table 'grade'

9.数据库已存在，无法创建

[Err] 1007 - Can't create database 'user'; database exists

10.数据库不存在，不能删除

[Err] 1008 - Can't drop database 'school'; database doesn't exist

11.在where 语句中，'6-166'字段是未知的
 

[Err] 1054 - Unknown column '6-166' in 'where clause'