mysql中整數(shù)數(shù)據(jù)類型tinyint詳解
1.1 tinyint類型說(shuō)明
數(shù)據(jù)類型 | 顯示長(zhǎng)度 | 占用字節(jié) | 有符號(hào) | 無(wú)符號(hào) |
---|---|---|---|---|
tinyint | 加上unsigned/zerofill:3 不加unsigned/zerofill:4 |
1(8bit) | -128至127 | 0至255 |
#### 格式 id tinyint(M) [unsigned] [zerofill] 字段名 數(shù)據(jù)類型(顯示長(zhǎng)度,不指定指定) 無(wú)符號(hào) 無(wú)符號(hào)且前導(dǎo)零填充 #### 關(guān)于tinyint最大數(shù)值是怎樣得來(lái)的 tinyint占用1字節(jié),1字節(jié)占用8位,經(jīng)過(guò)換算(2的8次方減1)就是255; #### 關(guān)于加上unsigned后的說(shuō)明 加上unsigned屬性后就是無(wú)符號(hào)(范圍是0~255的整數(shù),因?yàn)槭钦麛?shù),不會(huì)有符號(hào)"-",所以就是無(wú)符號(hào)) #### 關(guān)于加上zerofill后的說(shuō)明 zerofill屬性會(huì)把unsigned屬性也給帶上,這樣就是無(wú)符號(hào)(范圍是0~255,顯示長(zhǎng)度就是3),同時(shí)還會(huì) 進(jìn)行前導(dǎo)零填充(沒(méi)有達(dá)到顯示長(zhǎng)度的數(shù)值,例如:你插入1,顯示的是001)。 #### 不加unsigned和zerofill的說(shuō)明 字段后面不加上這兩個(gè)屬性中的任何一個(gè),就表示是有符號(hào)(范圍是-128~127,因?yàn)橛蟹?hào)"-",所有是有符號(hào))。
1.2 實(shí)踐環(huán)境說(shuō)明
#### 數(shù)據(jù)庫(kù)版本和默認(rèn)的存儲(chǔ)引擎 mysql> select @@version,@@default_storage_engine; +------------+--------------------------+ | @@version | @@default_storage_engine | +------------+--------------------------+ | 5.7.28-log | InnoDB | +------------+--------------------------+ 1 row in set (0.00 sec) #### 創(chuàng)建chenliang庫(kù) 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) #### 進(jìn)入chenliang庫(kù),并查看是否成功進(jìn)入到庫(kù)下面 mysql> use chenliang; Database changed mysql> select database(); +------------+ | database() | +------------+ | chenliang | +------------+ 1 row in set (0.01 sec) #### 查看事務(wù)是否自動(dòng)提交 mysql> select @@global.autocommit; +---------------------+ | @@global.autocommit | +---------------------+ | 1 | +---------------------+ 1 row in set (0.00 sec)
1.3 加unsigned屬性
1.3.1 SQL模式開(kāi)啟嚴(yán)格模式
SQL_MODE中開(kāi)啟了嚴(yán)格模式,即SQL_MODE參數(shù)中包含STRICT_TRANS_TABLES參數(shù)
#### 設(shè)置會(huì)話模式下的sql_mode中包含strict_trans_tables 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) #### 創(chuàng)建test1測(cè)試表(這里指定了UNSIGNED,也就是無(wú)符號(hào)) mysql> CREATE TABLE IF NOT EXISTS test1( -> id tinyint UNSIGNED -> )engine=innodb character set utf8 collate utf8_general_ci; Query OK, 0 rows affected (0.06 sec) ## id字段類型是tinyint unsigned,范圍就是0~255,其長(zhǎng)度是3;因?yàn)?55的長(zhǎng)度是3; #### 查看test1表的表結(jié)構(gòu) mysql> desc test1; +-------+---------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+---------------------+------+-----+---------+-------+ | id | tinyint(3) unsigned | YES | | NULL | | +-------+---------------------+------+-----+---------+-------+ 1 row in set (0.03 sec) #### 測(cè)試插入范圍0~255范圍整數(shù)和不在該范圍內(nèi)的整數(shù) mysql> insert into test1 values(-1); # 插入數(shù)值-1,錯(cuò)誤(不在0~255范圍內(nèi)) ERROR 1264 (22003): Out of range value for column 'id' at row 1 mysql> insert into test1 values(0); # 插入數(shù)值0,正常(在0~255范圍內(nèi)) Query OK, 1 row affected (0.06 sec) mysql> insert into test1 values(255); # 插入數(shù)值255,正常(在0~255范圍內(nèi)) Query OK, 1 row affected (0.05 sec) mysql> insert into test1 values(256); # 插入數(shù)值256,錯(cuò)誤(不在0~255范圍內(nèi)) ERROR 1264 (22003): Out of range value for column 'id' at row 1 mysql> select * from test1; +------+ | id | +------+ | 0 | | 255 | +------+ 2 rows in set (0.00 sec)
1.3.2 SQL模式未開(kāi)啟嚴(yán)格模式
SQL_MODE未開(kāi)啟嚴(yán)格模式,即SQL_MODE參數(shù)中不包含STRICT_TRANS_TABLES參數(shù)
#### 設(shè)置會(huì)話模式下sql_mode中不包含strit_trans_tables變量 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) #### 創(chuàng)建test11表(這里指定了UNSIGNED,也就是無(wú)符號(hào)) mysql> create table if not exists test11( -> id tinyint unsigned -> )engine=innodb character set utf8 collate utf8_general_ci; Query OK, 0 rows affected (0.00 sec) ## id字段類型是tinyint unsigned,范圍就是0~255,其長(zhǎng)度是3;因?yàn)?55的長(zhǎng)度是3; #### 查看test11表的表結(jié)構(gòu) mysql> desc test11; +-------+---------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+---------------------+------+-----+---------+-------+ | id | tinyint(3) unsigned | YES | | NULL | | +-------+---------------------+------+-----+---------+-------+ 1 row in set (0.00 sec) #### 測(cè)試插入范圍0~255范圍整數(shù)和不在該范圍內(nèi)的整數(shù) mysql> insert into test11(id) values(-1); Query OK, 1 row affected, 1 warning (0.00 sec) ## 不在范圍內(nèi),插入沒(méi)有報(bào)錯(cuò)(因?yàn)閟ql_mode中沒(méi)有開(kāi)啟嚴(yán)格模式) ## 插入到表中的數(shù)據(jù)不是-1,而是0 mysql> insert into test11(id) values(0); Query OK, 1 row affected (0.01 sec) ## 沒(méi)報(bào)錯(cuò),因?yàn)樵诜秶鷥?nèi),插入到表中的也是0 mysql> insert into test11(id) values(255); Query OK, 1 row affected (0.01 sec) ## 沒(méi)報(bào)錯(cuò),因?yàn)樵诜秶鷥?nèi),插入到表中的也是255 mysql> insert into test11(id) values(256); Query OK, 1 row affected, 1 warning (0.00 sec) ## 不在范圍內(nèi),插入沒(méi)有報(bào)錯(cuò)(因?yàn)閟ql_mode中沒(méi)有開(kāi)啟嚴(yán)格模式) ## 插入到表中的數(shù)據(jù)不是256,而是255 mysql> select * from test11; +------+ | id | +------+ | 0 | | 0 | | 255 | | 255 | +------+ 4 rows in set (0.00 sec)
1.4 加zerofill屬性
1.4.1 SQL模式開(kāi)啟嚴(yán)格模式
SQL_MODE中開(kāi)啟了嚴(yán)格模式,即SQL_MODE參數(shù)中包含STRICT_TRANS_TABLES參數(shù)
## 設(shè)置會(huì)話模式下的sql_mode中包含strict_trans_tables 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) ## 創(chuàng)建test2測(cè)試表(這里指定了zerofill,會(huì)前導(dǎo)零填充,同時(shí)還會(huì)帶上unsigned) mysql> CREATE TABLE IF NOT EXISTS test2( -> id tinyint zerofill -> )engine=innodb character set utf8 collate utf8_general_ci; Query OK, 0 rows affected (0.01 sec) ## id字段類型是tinyint zerofill,范圍就是0~255,其長(zhǎng)度是3;因?yàn)?55的長(zhǎng)度是3; ## 查看test2表的表結(jié)構(gòu) mysql> desc test2; +-------+------------------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+------------------------------+------+-----+---------+-------+ | id | tinyint(3) unsigned zerofill | YES | | NULL | | +-------+------------------------------+------+-----+---------+-------+ 1 row in set (0.00 sec) ## 測(cè)試插入范圍0~255范圍整數(shù)和不在該范圍內(nèi)的整數(shù) mysql> insert into test2 values(-1); # 插入數(shù)值-1,錯(cuò)誤(不在0~255范圍內(nèi)) ERROR 1264 (22003): Out of range value for column 'id' at row 1 mysql> insert into test2 values(0); # 插入數(shù)值0,正常(在0~255范圍內(nèi)) Query OK, 1 row affected (0.06 sec) mysql> insert into test2 values(255); # 插入數(shù)值255,正常(在0~255范圍內(nèi)) Query OK, 1 row affected (0.05 sec) mysql> insert into test2 values(256); # 插入數(shù)值256,錯(cuò)誤(不在0~255范圍內(nèi)) ERROR 1264 (22003): Out of range value for column 'id' at row 1 mysql> select * from test2; +------+ | id | +------+ | 000 | | 255 | +------+ 2 rows in set (0.00 sec)
1.4.2 SQL模式未開(kāi)啟嚴(yán)格模式
SQL_MODE未開(kāi)啟嚴(yán)格模式,即SQL_MODE參數(shù)中不包含STRICT_TRANS_TABLES參數(shù)
## 設(shè)置會(huì)話模式下sql_mode中不包含strit_trans_tables變量 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) ## 創(chuàng)建test22表(這里指定了zerofill,會(huì)前導(dǎo)零填充,同時(shí)還會(huì)帶上unsigned) mysql> create table if not exists test22( -> id tinyint zerofill -> )engine=innodb character set utf8 collate utf8_general_ci; Query OK, 0 rows affected (0.00 sec) ## id字段類型是tinyint unsigned,范圍就是0~255,其長(zhǎng)度是3;因?yàn)?55的長(zhǎng)度是3; ## 查看test22表的表結(jié)構(gòu) mysql> desc test22; +-------+------------------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+------------------------------+------+-----+---------+-------+ | id | tinyint(3) unsigned zerofill | YES | | NULL | | +-------+------------------------------+------+-----+---------+-------+ 1 row in set (0.00 sec) ## 測(cè)試插入范圍0~255范圍整數(shù)和不在該范圍內(nèi)的整數(shù) mysql> insert into test22(id) values(-1); Query OK, 1 row affected, 1 warning (0.00 sec) ## 不在范圍,插入沒(méi)報(bào)錯(cuò)(因?yàn)閟ql_mode中沒(méi)有開(kāi)啟嚴(yán)格模式); ## 但到表中的不是-1,而是0,但因?yàn)橛衵erofill參數(shù),所以顯示時(shí)會(huì)前導(dǎo)零序填充; mysql> insert into test22(id) values(0); Query OK, 1 row affected (0.01 sec) ## 沒(méi)報(bào)錯(cuò),因?yàn)樵诜秶鷥?nèi),插入到表中的也是0 mysql> insert into test22(id) values(255); Query OK, 1 row affected (0.01 sec) ## 沒(méi)報(bào)錯(cuò),因?yàn)樵诜秶鷥?nèi),插入到表中的也是255 mysql> insert into test22(id) values(256); Query OK, 1 row affected, 1 warning (0.00 sec) ## 不在范圍,插入沒(méi)報(bào)錯(cuò)(sql_mode中沒(méi)有開(kāi)啟嚴(yán)格模式) ## 但到表中的數(shù)據(jù)不是256,而是255 mysql> select * from test22; +------+ | id | +------+ | 000 | | 000 | | 255 | | 255 | +------+ 4 rows in set (0.00 sec)
1.5 不加unsigned和zerofill屬性
1.5.1 SQL模式開(kāi)啟嚴(yán)格模式
SQL_MODE中開(kāi)啟了嚴(yán)格模式,即SQL_MODE參數(shù)中包含STRICT_TRANS_TABLES參數(shù)
## 設(shè)置會(huì)話模式下的sql_mode中包含strict_trans_tables 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) ## 創(chuàng)建test3表(不加unsigned和zerofill) mysql> CREATE TABLE test3( -> id tinyint -> )engine=innodb character set utf8 collate utf8_general_ci; Query OK, 0 rows affected (0.06 sec) ## id字段的類型為tinyint,其范圍是-128至127,其顯示長(zhǎng)度是4,因?yàn)橐@示符號(hào)("-") ## 查看test3表的表結(jié)構(gòu) mysql> desc test3; +-------+------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+------------+------+-----+---------+-------+ | id | tinyint(4) | YES | | NULL | | +-------+------------+------+-----+---------+-------+ 1 row in set (0.01 sec) ## 測(cè)試插入-128~127范圍的整數(shù)和不在該范圍內(nèi)的整數(shù) mysql> insert into test3(id) values(-129); # 插入數(shù)值-129,錯(cuò)誤,不在范圍內(nèi) ERROR 1264 (22003): Out of range value for column 'id' at row 1 mysql> insert into test3(id) values(-128); # 插入數(shù)值-128,正確,在范圍內(nèi) Query OK, 1 row affected (0.00 sec) mysql> insert into test3(id) values(127); # 插入數(shù)值127,正確,在范圍內(nèi) Query OK, 1 row affected (0.01 sec) mysql> insert into test3(id) values(128); # 插入數(shù)值128,錯(cuò)誤,不在范圍內(nèi) ERROR 1264 (22003): Out of range value for column 'id' at row 1 mysql> select * from test3; +------+ | id | +------+ | -128 | | 127 | +------+ 2 rows in set (0.00 sec)
1.5.2 SQL模式未開(kāi)啟嚴(yán)格模式
SQL_MODE中未開(kāi)啟嚴(yán)格模式,即SQL_MODE參數(shù)中不包含STRICT_TRANS_TABLES參數(shù)
## 設(shè)置會(huì)話模式下sql_mode中不包含strit_trans_tables變量 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) ## 創(chuàng)建test33表(不加unsigned和zerofill) mysql> CREATE TABLE test33( -> id tinyint -> )engine=innodb character set utf8 collate utf8_general_ci; Query OK, 0 rows affected (0.00 sec) ## id字段的類型為tinyint,其范圍是-128至127,其顯示長(zhǎng)度是4,因?yàn)橐@示符號(hào)("-") ## 查看test33表的表結(jié)構(gòu) mysql> desc test33; +-------+------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+------------+------+-----+---------+-------+ | id | tinyint(4) | YES | | NULL | | +-------+------------+------+-----+---------+-------+ 1 row in set (0.00 sec) ## 測(cè)試插入-128~127范圍的整數(shù)和不在該范圍內(nèi)的整數(shù) mysql> insert into test33(id) values(-129); Query OK, 1 row affected, 1 warning (0.00 sec) ## 不在范圍內(nèi),插入未報(bào)錯(cuò),因?yàn)閟ql_mode中沒(méi)有開(kāi)啟嚴(yán)格模式 ## 插入到表中的不是-129,而是-128; mysql> insert into test33(id) values(-128); Query OK, 1 row affected (0.01 sec) ## 在范圍內(nèi),插入不報(bào)錯(cuò),插入的是多少就是多少 mysql> insert into test33(id) values(127); Query OK, 1 row affected (0.00 sec) ## 在范圍內(nèi),插入不報(bào)錯(cuò),插入的是多少就是多少 mysql> insert into test33(id) values(128); Query OK, 1 row affected, 1 warning (0.01 sec) ## 不在范圍內(nèi),插入未報(bào)錯(cuò),因?yàn)閟ql_mode中沒(méi)有開(kāi)啟嚴(yán)格模式 ## 插入到表中的不是128,而是127; mysql> select * from test33; +------+ | id | +------+ | -128 | | -128 | | 127 | | 127 | +------+ 4 rows in set (0.00 sec)
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