Question

mysql int 长度11和10的区别

Answer 1

总结，int(M) zerofill，加上zerofill后M才表现出有点点效果，比如 int(3) zerofill,你插入到数据库里的是10,则实际插入为010,也就是在前面补充加了一个0.如果int(3)和int(10)不加zerofill,则它们没有什么区别．M不是用来限制int个数的．int(M)的最大值和最小值与undesigned有关，最下面那副图有说明．
mysql> create table t (t int(3) zerofill);
Query OK, 0 rows affected (0.00 sec)

mysql> insert into t set t = 10;
Query OK, 1 row affected (0.00 sec)

mysql> select * from t;
+——+
| t |
+——+
| 010 |
+——+
1 row in set (0.11 sec)

Zerofill with default width, the same as int(10):

mysql> create table t (t int zerofill);
Query OK, 0 rows affected (0.02 sec)

mysql> insert into t set t = 10;
Query OK, 1 row affected (0.02 sec)

mysql> select * from t;
+————+
| t |
+————+
| 0000000010 |
+————+
1 row in set (0.08 sec)

Without zerofill:

mysql> create table t (t int);
Query OK, 0 rows affected (0.01 sec)

mysql> insert into t set t = 10;
Query OK, 1 row affected (0.01 sec)

mysql> select * from t;
+——+
| t |
+——+
| 10 |
+——+
1 row in set (0.00 sec)