标签：测试表 mic ble nod http desc sele 符号 补充
一、smallint类型说明
id smallint(M) [UNSIGNED] [ZEROFILL] 字段名 字段类型(显示长度,生产中创建表时不指定) [无符号] [前导填充] unsigned： 01：smallint(M)后面加上unsigned,就是无符号,只可以插入正整数,其范围就是0~65535; 02：2字节就是16位,那么2的16次方减1就是65535; 03：因为加了unsigned就是正整数,也就是无符号,所以范围是0~65535; 04：65535长度是5;不指定长度,例:smallint unsigned,其显示的长度就是smallint(5), 但当插入的正整数长度达不到长度5时,不会自动补充,1显示1;65535显示65535; zerofill： 01：smallint(M)后面加上zerofill参数,会把unsigned带上,也就是无符号,只可插入正整 数,其范围 0~65535 02：2字节就是16位,那么2的16次方减1就是65535; 03：因为会带上unsigned,所以也是无符号,只可插入正整数,范围是0~65535; 04：65535的长度是5,不长度时,例; smallint zerofill,其长度就是smallint(5),当你插入 的正整数长度达不到长度5时,会前导0填充,1显示00001,65535显示65535; 不加unsigned和zerofill 不在smallint后加上unsigned或zerofill,其默认是有符号,也就是可以插入正整数和负整 数,且最大范围的长度是5,但是因为要显示符号("-"),所以显示的是tinyint(6),虽然显示的 长度是6,但对于插入的数据的长度不够长度6时,也不会自动前导零填充; 特别说明 01：在为字段指定类型的时,一般不指定其的长度,例如：samallint或samllint unsigned 02：插入的数据若超出范围,能否插入成功,这个得根据sql_mode中是否开启严格模式,即sql_mode 参数中是否包含STRICT_TRANS_TABLES变量;
二、实践环境准备
-- 数据库版本和默认的存储引擎 mysql> select @@version,@@default_storage_engine; +------------+--------------------------+ | @@version | @@default_storage_engine | +------------+--------------------------+ | 5.7.28-log | InnoDB | +------------+--------------------------+ 1 row in set (0.00 sec) -- 创建chenliang库 mysql> create database if not exists chenliang; Query OK, 1 row affected (0.03 sec) mysql> show databases like "chenliang"; +----------------------+ | Database (chenliang) | +----------------------+ | chenliang | +----------------------+ 1 row in set (0.03 sec) -- 进入chenliang库 mysql> use chenliang; Database changed mysql> select database(); +------------+ | database() | +------------+ | chenliang | +------------+ 1 row in set (0.01 sec) -- 查看事务是否自动提交 mysql> select @@global.autocommit; +---------------------+ | @@global.autocommit | +---------------------+ | 1 | +---------------------+ 1 row in set (0.00 sec)
三、测试1【加unsigned参数】
SQL_MODE中开启了严格模式,即SQL_MODE参数中包含STRICT_TRANS_TABLES参数
-- 设置会话模式下sql_mode中包含strict_trans_tables变量
mysql> set session sql_mode="STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION";
Query OK, 0 rows affected (0.00 sec)
mysql> select @@sql_mode\G
*************************** 1. row ***************************
@@sql_mode: STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
1 row in set (0.00 sec)
-- 创建test1测试表（这里指定了UNSIGNED，也就是无符号）
mysql> CREATE TABLE IF NOT EXISTS test1(
-> id smallint UNSIGNED
-> );
Query OK, 0 rows affected (0.03 sec)
-- PS
-- test1表的id字段指定了unsigned参数,那么id字段的范围就是0~65535
-- 显示长度为smallint(5),因为65535的长度是5
-- 查看test1表的表结构
mysql> desc test1;
+-------+----------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------------------+------+-----+---------+-------+
| id | smallint(5) unsigned | YES | | NULL | |
+-------+----------------------+------+-----+---------+-------+
1 row in set (0.00 sec)
-- 测试插入范围0~65535的整数和不在该范围内的整数
mysql> insert into test1(id) values(-1); # 插入数值-1,报错,不在范围内
ERROR 1264 (22003): Out of range value for column ‘id‘ at row 1
mysql> insert into test1(id) values(0); # 插入数值0,正确,在范围内
Query OK, 1 row affected (0.00 sec)
mysql> insert into test1(id) values(65535); # 插入数值65535,正确,在范围内
Query OK, 1 row affected (0.01 sec)
mysql> insert into test1(id) values(65536); # 插入数值65536,报错,不在范围内
ERROR 1264 (22003): Out of range value for column ‘id‘ at row 1
mysql> select * from test1;
+-------+
| id |
+-------+
| 0 |
| 65535 |
+-------+
2 rows in set (0.00 sec)
SQL_MODE末开启严格模式,即SQL_MODE参数中不包含STRICT_TRANS_TABLES参数
-- 设置会话模式下sql_mode中不开启严格模式,即不包含strict_trans_tables变量
mysql> set session sql_mode="NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION";
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> select @@sql_mode\G
*************************** 1. row ***************************
@@sql_mode: NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
1 row in set (0.00 sec)
## 创建test11表(这里加了unsigned参数哈,也就是无符号)
mysql> create table if not exists test11(
-> id smallint unsigned
-> );
Query OK, 0 rows affected (0.01 sec)
-- PS
-- test11表的id字段指定了unsigned参数,那么id字段的范围就是0~65535
-- 显示长度为smallint(5),因为65535的长度是5
-- 查看test11表的表结构
mysql> desc test11;
+-------+----------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------------------+------+-----+---------+-------+
| id | smallint(5) unsigned | YES | | NULL | |
+-------+----------------------+------+-----+---------+-------+
1 row in set (0.00 sec)
-- 测试插入范围0~65535的整数和不在该范围内的整数
mysql> insert into test11(id) values(-1);
Query OK, 1 row affected, 1 warning (0.01 sec)
-- 不在范围内,插入未报错(因为sql_mode中没有开启严格模式)
-- 插入到表中的数据不是-1,而是0
mysql> insert into test11(id) values(0);
Query OK, 1 row affected (0.00 sec)
-- 在范围内,插入未报错,插入的是多少就是多少
mysql> insert into test11(id) values(65535);
Query OK, 1 row affected (0.00 sec)
-- 在范围内,插入未报错,插入的是多少就是多少
mysql> insert into test11(id) values(65536);
Query OK, 1 row affected, 1 warning (0.00 sec)
-- 不在范围内,插入未报错(因为sql_mode中没有开启严格模式)
-- 插入到表中的数据不是65536,而是65535
mysql> select * from test11;
+-------+
| id |
+-------+
| 0 |
| 0 |
| 65535 |
| 65535 |
+-------+
4 rows in set (0.00 sec)
四、测试2【加zerofill参数】
SQL_MODE中开启了严格模式,即SQL_MODE参数中包含STRICT_TRANS_TABLES参数
-- 设置会话模式下sql_mode中包含strict_trans_tables变量
mysql> set session sql_mode="STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION";
Query OK, 0 rows affected (0.00 sec)
mysql> select @@sql_mode\G
*************************** 1. row ***************************
@@sql_mode: STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
1 row in set (0.00 sec)
-- 创建test2表，（这里指定了zerofill,也就是前导零填充）
mysql> create table if not exists test2(
-> id smallint zerofill
-> );
Query OK, 0 rows affected (0.12 sec)
-- PS
-- id字段指定了zerofill参数,它会把unsigned参数也带上,那么id字段的范围0~65535;
-- 显示长度是smallint(5),因为65535的长度是5;
-- 查看test2表的表结构
mysql> desc test2;
+-------+-------------------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------------------------+------+-----+---------+-------+
| id | smallint(5) unsigned zerofill | YES | | NULL | |
+-------+-------------------------------+------+-----+---------+-------+
1 row in set (0.00 sec)
-- 测试插入范围0~65535的整数和不在该范围内的整数
mysql> insert into test2(id) values(-1); # 插入数值-1,报错,不在范围内
ERROR 1264 (22003): Out of range value for column ‘id‘ at row 1
mysql> insert into test2(id) values(0); # 插入数值0,正确,在范围内
Query OK, 1 row affected (0.00 sec)
mysql> insert into test2(id) values(65535); # 插入数值65535,正确,在范围内
Query OK, 1 row affected (0.01 sec)
mysql> insert into test2(id) values(65536); # 插入数值65536,报错,不在范围内
ERROR 1264 (22003): Out of range value for column ‘id‘ at row 1
mysql> select * from test2;
+-------+
| id |
+-------+
| 00000 |
| 65535 |
+-------+
2 rows in set (0.00 sec)
SQL_MODE未开启严格模式,即SQL_MODE参数中不包含STRICT_TRANS_TABLES变量
-- 设置会话模式下sql_mode中不开启严格模式,即不包含strict_trans_tables变量
mysql> set session sql_mode="NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION";
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> select @@sql_mode\G
*************************** 1. row ***************************
@@sql_mode: NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
1 row in set (0.00 sec)
-- 创建test22表(这里加上zerofill参数,前导零填充,同时也会把unsigned参数也带上)
mysql> create table if not exists test22(
-> id smallint zerofill
-> );
Query OK, 0 rows affected (0.01 sec)
-- PS
-- id字段指定了zerofill参数,它会把unsigned参数也带上,那么id字段的范围0~65535;
-- 显示长度是smallint(5),因为65535的长度是5;
mysql> desc test22;
+-------+-------------------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------------------------+------+-----+---------+-------+
| id | smallint(5) unsigned zerofill | YES | | NULL | |
+-------+-------------------------------+------+-----+---------+-------+
1 row in set (0.01 sec)
-- 测试插入范围0~65535的整数和不在该范围内的整数
mysql> insert into test22(id) values(-1);
Query OK, 1 row affected, 1 warning (0.00 sec)
-- 不在范围内,插入未报错（因为sql_mode中未开启严格模式）
-- 插入到表中的数据不是-1,而是0,但显示的时候会前导零填充,因为有zerofill参数
mysql> insert into test22(id) values(0);
Query OK, 1 row affected (0.01 sec)
-- 在范围内,插入未报错,插入是什么就是什么,
-- 但因为有zerofill参数,显示时就会前导零填充
mysql> insert into test22(id) values(65535);
Query OK, 1 row affected (0.00 sec)
-- 在范围内,插入未报错,插入是什么就是什么
mysql> insert into test22(id) values(65536);
Query OK, 1 row affected, 1 warning (0.00 sec)
-- 不在范围内,插入未报错（因为sql_mode中未开启严格模式）
-- 插入到表中的数据不是65536,而是65535
mysql> select * from test22;
+-------+
| id |
+-------+
| 00000 |
| 00000 |
| 65535 |
| 65535 |
+-------+
4 rows in set (0.00 sec)
五、测试3【不加unsigned和zerofill参数】
SQL_MODE中开启了严格模式,即SQL_MODE参数中包含STRICT_TRANS_TABLES参数
-- 设置会话模式下sql_mode中包含strict_trans_tables变量
mysql> set session sql_mode="STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION";
Query OK, 0 rows affected (0.00 sec)
mysql> select @@sql_mode\G
*************************** 1. row ***************************
@@sql_mode: STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
1 row in set (0.00 sec)
-- 创建test3表（不加unsigned和zerofill）
mysql> create table if not exists test3(
-> id smallint
-> );
Query OK, 0 rows affected (0.08 sec)
-- PS
-- test3表的id字段没指定unsigned和zerofill参数,那么id字段范围就是-32768~32767
-- 因为要显示符号("-"),可以显示长度是smallint(6)
-- 查看test3表的表结构
mysql> desc test3;
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id | smallint(6) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
1 row in set (0.01 sec)
-- 测试插入-32768~32767范围内的整数和不在该范围内的整数
mysql> insert into test3(id) values(-32769); #插入数值-32769,错误,不在范围内
ERROR 1264 (22003): Out of range value for column ‘id‘ at row 1
mysql> insert into test3(id) values(-32768); #插入数值-32768,正确,在范围内
Query OK, 1 row affected (0.01 sec)
mysql> insert into test3(id) values(32767); #插入数值32767,正确,在范围内
Query OK, 1 row affected (0.00 sec)
mysql> insert into test3(id) values(32768); #插入数值32768,错误,不在范围内
ERROR 1264 (22003): Out of range value for column ‘id‘ at row 1
mysql> select * from test3;
+--------+
| id |
+--------+
| -32768 |
| 32767 |
+--------+
2 rows in set (0.00 sec)
SQL_MODE未开启严格模式,即SQL_MODE参数中不包含STRICT_TRANS_TABLES变量
-- 设置会话模式下sql_mode中不开启严格模式,即不包含strict_trans_tables变量
mysql> set session sql_mode="NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION";
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> select @@sql_mode\G
*************************** 1. row ***************************
@@sql_mode: NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
1 row in set (0.00 sec)
-- 创建test33表(不加zerofill和unsigned参数)
mysql> create table if not exists test33(
-> id smallint
-> );
Query OK, 0 rows affected (0.00 sec)
-- PS
-- test33表的id字段没指定unsigned和zerofill参数,那么id字段范围就是-32768~32767
-- 因为要显示符号("-"),可以显示长度是smallint(6)
mysql> desc test33;
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id | smallint(6) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
1 row in set (0.00 sec)
-- 测试插入-32768~32767范围内的整数和不在该范围内的整数
mysql> insert into test33(id) values(-32769);
Query OK, 1 row affected, 1 warning (0.00 sec)
-- 不在范围内,插入未报错(因为sql_mode中没有开启严格格式)
-- 插入的数据不是-32769,而是-32768
mysql> insert into test33(id) values(-32768);
Query OK, 1 row affected (0.01 sec)
-- 在范围内,插入不会报错,插入的是什么就是什么
mysql> insert into test33(id) values(32767);
Query OK, 1 row affected (0.00 sec)
-- 在范围内,插入不会报错,插入的是什么就是什么
mysql> insert into test33(id) values(32768);
Query OK, 1 row affected, 1 warning (0.00 sec)
-- 不在范围内,插入未报错(因为sql_mode中没有开启严格格式)
-- 插入的数据不是32768,而是32767
mysql> select * from test33;
+--------+
| id |
+--------+
| -32768 |
| -32768 |
| 32767 |
| 32767 |
+--------+
4 rows in set (0.00 sec)
标签：测试表 mic ble nod http desc sele 符号 补充
原文地址：https://www.cnblogs.com/chenliangc/p/11107232.html
