MySQL 5.7 模式(SQL_MODE)詳細說明

5.7 默認模式:
ONLY_FULL_GROUP_BY, STRICT_TRANS_TABLES, NO_ZERO_IN_DATE, NO_ZERO_DATE, 
ERROR_FOR_DIVISION_BY_ZERO, NO_AUTO_CREATE_USER, NO_ENGINE_SUBSTITUTION,
 
5.7.4 廢棄:ERROR_FOR_DIVISION_BY_ZERO
5.7.5 默認:ONLY_FULL_GROUP_BY , STRICT_TRANS_TABLES
5.7.7 默認:NO_AUTO_CREATE_USER
5.7.8 默認:ERROR_FOR_DIVISION_BY_ZERO, NO_ZERO_DATE, NO_ZERO_IN_DATE
 
 
命令行啓動服務設置: --sql-mode="modes"
配置文件中的設置: sql-mode="modes" 
 
對於多個的模式用逗號隔開。清除模式則設置爲空字符:
--sql-mode="" 
sql-mode="" 
 
在服務運行時改變模式,有全局和會話級別:
SET GLOBAL sql_mode = 'modes';
SET SESSION sql_mode = 'modes';
 
全局模式在線設置需要超級權限(SUPER),新的連接纔會生效;會話級別模式每個客戶端都可設置。
 
查看當前模式:
SELECT @@GLOBAL.sql_mode;
SELECT @@SESSION.sql_mode;
SELECT @@sql_mode; 
 
在未了解各種模式的影響下,表分區後建議不要再變更模式,同步複製的實例也建議模式保持一致。

======================================================================
【ANSI】
等價於 REAL_AS_FLOAT, PIPES_AS_CONCAT, ANSI_QUOTES, IGNORE_SPACE. ONLY_FULL_GROUP_BY(MySQL 5.7.5)
======================================================================
REAL_AS_FLOAT :REALFLOAT 的同義詞(默認情況, REALDOUBLE 的同義詞).
PIPES_AS_CONCAT : 管道符(||) 作爲連接符.(默認使用函數 CONCAT 連接字符)
ANSI_QUOTES :標準引號, 雙引號不作爲字符串引號,作爲關鍵字標識符引號
IGNORE_SPACE :對於內置函數與其他字符間的空格,忽略空格
 
------------------------------
【ANSI_QUOTES】
------------------------------
create table max(id int); #報錯 (相同)
create table max (id int); #不報錯 (相同)
create table `max`(id int); #不報錯 (相同)
create table 'max'(id int); #報錯 (相同)
 
create table "max"(id int);  #報錯 sql_mode='';
create table "max"(id int);  #不報錯 sql_mode='ANSI_QUOTES';
 
SELECT "AAA"; #不報錯 sql_mode='';
SELECT "AAA"; #報錯  sql_mode='ANSI_QUOTES';
------------------------------
【IGNORE_SPACE】
------------------------------
create table max(id int); #報錯 (相同)
 
create table max (id int);  #不報錯 sql_mode='';
create table max (id int);  #報錯 sql_mode='IGNORE_SPACE';
 
------------------------------
【PIPES_AS_CONCAT】
------------------------------
SET sql_mode='PIPES_AS_CONCAT';
 
select 'aa' || 'bb';
select CONCAT('aa' , 'bb');
 
======================================================================
【STRICT_TRANS_TABLES】
對事務型表操作,插入表時如果第一行數據不符合約束則終止執行並回滾。
======================================================================
create table test(value int(1));
SET sql_mode=''; #默認只要第一個值
 
insert into test(value) values('a'),(1),(2147483647); #不報錯
insert into test(value) values(1),('a'),(2147483647); #不報錯
select * from test;
+------------+
| value      |
+------------+
|          1 |
|          0 |
| 2147483647 |
+------------+
 
#後面刪除表不再說明!
drop table test; 
create table test(value int(1));
 
SET sql_mode='STRICT_TRANS_TABLES'; #每個值都判斷
 
insert into test(value) values('a'),(1),(2147483647); #報錯,第一行'a'錯誤。
insert into test(value) values(1),('a'),(2147483647); #報錯,第二行'a'錯誤。
 
======================================================================
【TRADITIONAL】
======================================================================
MySQL 5.7.4 以前版本 和 MySQL 5.7.8 及以上版本:
STRICT_TRANS_TABLES, STRICT_ALL_TABLES, NO_AUTO_CREATE_USER
, NO_ENGINE_SUBSTITUTION,NO_ZERO_IN_DATE, NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO.
 
MySQL 5.7.45.7.7 版本:
STRICT_TRANS_TABLES, STRICT_ALL_TABLES, NO_AUTO_CREATE_USER, NO_ENGINE_SUBSTITUTION. 
(STRICT_ALL_TABLES / STRICT_TRANS_TABLES 包含 NO_ZERO_IN_DATE, NO_ZERO_DATE, ERROR_FOR_DIVISION_BY_ZERO)
 
------------------------------
【STRICT_ALL_TABLES】
包括: ERROR_FOR_DIVISION_BY_ZERO, NO_ZERO_DATE, NO_ZERO_IN_DATE
------------------------------
 
------------------------------
【NO_AUTO_CREATE_USER】禁止使用 GRANT 創建密碼爲空的用戶。
------------------------------
標準寫法:
create user user01@'localhost' identified by 'user01'; 
grant all on test.* to user01@'localhost';  
flush privileges;  
 
 
SET sql_mode='';
 
#不報錯(無需要設置密碼)
grant all on test.* to user01@'localhost';  
 
 
SET sql_mode='NO_AUTO_CREATE_USER';
 
#報錯 ERROR 1133 (42000): Can't find any matching row in the user table
grant all on test.* to user02@'localhost';  
 
#正確,需要設置密碼
grant all on test.* to user02@'localhost' identified by 'user02'; 
 
------------------------------
【NO_ENGINE_SUBSTITUTION】
默認情況創建或修改表的存儲引擎不支持時,自動轉爲默認的INNODB;
使用該模式後,存儲引擎不支持時則報錯。
------------------------------
#查看所有存儲引擎
show engines;
 
SET sql_mode='';
create table test(id int) ENGINE=FEDERATED;
select table_name,engine from information_schema.tables where table_schema='test' and table_name='test';
+------------+--------+
| table_name | engine |
+------------+--------+
| test       | InnoDB |
+------------+--------+
 
SET sql_mode='NO_ENGINE_SUBSTITUTION';
create table test(id int) ENGINE=FEDERATED;
直接報錯:ERROR 1286 (42000): Unknown storage engine 'FEDERATED'
 
------------------------------
【NO_ZERO_IN_DATE】日期格式(月日)是否支持'00'.
------------------------------
create table test(value date);
SET sql_mode='';
insert into test(value) values('2018-00-00'); #結果爲 '2018-00-00'
 
SET sql_mode='NO_ZERO_IN_DATE';
insert into test(value) values('2017-00-00'); #不符合,轉爲 '0000-00-00'
 
 
------------------------------
【NO_ZERO_DATE】 不允許插入 '0000-00-00' 日期
------------------------------
create table test(value date);
 
SET sql_mode='';
insert into test(value) values('0000-00-00'); #無警告 warning
 
SET sql_mode='STRICT_TRANS_TABLES';
insert into test(value) values('0000-00-00'); #無警告 warning
 
SET sql_mode='NO_ZERO_DATE';
insert into test(value) values('0000-00-00'); #有警告 warning
 
SET sql_mode='NO_ZERO_DATE,STRICT_TRANS_TABLES';
insert into test(value) values('0000-00-00'); #報錯終止
 
------------------------------
【ERROR_FOR_DIVISION_BY_ZERO】 0爲除數時報錯
------------------------------
create table test(value int);
 
SET sql_mode='';  
select 10/0;  #無警告 warning
insert into test(value) values(10/0);   #無警告 warning
 
SET sql_mode='STRICT_TRANS_TABLES'; 
select 10/0;   #無警告 warning
insert into test(value) values(10/0);  #無警告 warning
 
SET sql_mode='ERROR_FOR_DIVISION_BY_ZERO'; 
select 10/0;  #有警告 warning
insert into test(value) values(10/0);  #有警告 warning
 
SET sql_mode='ERROR_FOR_DIVISION_BY_ZERO,STRICT_TRANS_TABLES';
select 10/0; #有警告 warning
insert into test(value) values(10/0); #報錯:ERROR 1365 (22012): Division by 0
 
======================================================================
【ALLOW_INVALID_DATES】
檢查日期格式合法性(DATEDATETIME,TIMESTAMP )
======================================================================
--	drop table test;
create table test(createdate date,name varchar(10));
 
SET sql_mode='';
select @@sql_mode;
 
#月日超出了範圍,則變爲: 0000-00-00
insert into test values ('2018-02-32','a');
insert into test values ('2018-13-01','b');
select * from test;
+------------+------+
| createdate | name |
+------------+------+
| 0000-00-00 | a    |
| 0000-00-00 | b    |
+------------+------+
 
SET sql_mode='ALLOW_INVALID_DATES';
select @@sql_mode;
 
insert into test values ('2018-02-32','d');
insert into test values ('2018-13-01','e');
select * from test;
+------------+------+
| createdate | name |
+------------+------+
| 0000-00-00 | a    |
| 0000-00-00 | b    |
| 0000-00-00 | d    |
| 0000-00-00 | e    |
+------------+------+
 
# ALLOW_INVALID_DATES 似乎沒有起作用,啓用嚴格模式 STRICT_TRANS_TABLES 或 STRICT_ALL_TABLES
#啓用後插入不合法日期,提示錯誤並終止。即嚴格模式下不允許插入非法值。
 
SET sql_mode='ALLOW_INVALID_DATES,STRICT_TRANS_TABLES';
insert into test values ('2018-02-32','f');
ERROR 1292 (22007): Incorrect date value: '2018-02-32' for column 'createdate' at row
 
SET sql_mode='STRICT_TRANS_TABLES';
insert into test values ('2018-02-32','g');
ERROR 1292 (22007): Incorrect date value: '2018-02-32' for column 'createdate' at row 1
 
#其他正常插入
insert into test values ('0000-00-00','h');
 
======================================================================
【NO_AUTO_VALUE_ON_ZERO】
運行序列中插入 "0",如果 id 不約束唯一, 可插入多個。插入 NULL 值默認都會自增。
======================================================================
--	drop table test;
create table test(id int not null auto_increment,name varchar(10),key(id));
 
SET sql_mode='';
 
insert into test values (1,'a');
insert into test values (0,'b');
insert into test values (null,'c');
select * from test;
+----+------+
| id | name |
+----+------+
|  1 | a    |
|  2 | b    |
|  3 | c    |
+----+------+
 
# 運行序列中插入 "0",如果 id 不約束唯一, 可插入多個
SET sql_mode='NO_AUTO_VALUE_ON_ZERO';
 
insert into test values (0,'d');
insert into test values (null,'e');
select * from test;
+----+------+
| id | name |
+----+------+
|  0 | d    |
|  1 | a    |
|  2 | b    |
|  3 | c    |
|  4 | e    |
+----+------+
 
======================================================================
【HIGH_NOT_PRECEDENCE】
未使用模式 HIGH_NOT_PRECEDENCE, "not id between 2 and 4" 相當於 "not (id between 2 and 4)"
使用模式   HIGH_NOT_PRECEDENCE, "not id between 2 and 4" 相當於 "(not id) between 2 and 4".
======================================================================
--	drop table test;
create table test(id int);
insert into test values (1),(2),(3),(4),(5);
 
SET sql_mode='';
 
SELECT NOT 1 BETWEEN -5 AND 5; #結果爲0
select * from test where not id between 2 and 4;   #結果爲:1、5
select * from test where not (id between 2 and 4); #結果爲:1、5
select * from test where (not id) between 2 and 4; #結果爲空
 
SET sql_mode='HIGH_NOT_PRECEDENCE';
 
SELECT NOT 1 BETWEEN -5 AND 5; #結果爲1
select * from test where not id between 2 and 4;   #結果爲空
select * from test where not (id between 2 and 4); #結果爲:1、5
select * from test where (not id) between 2 and 4; #結果爲空
 
======================================================================
【NO_BACKSLASH_ESCAPES】反斜槓"\"爲普通字符而不是轉義字符。
======================================================================
SET sql_mode='';
select '\\';
 
SET sql_mode='NO_BACKSLASH_ESCAPES';
select '\\';
 
======================================================================
【NO_UNSIGNED_SUBTRACTION】
UNSIGNED 類型如果得到一個負值,則報錯。(儘量不要 UNSIGNED)
======================================================================
SET sql_mode='';
select cast(0 as unsigned) - 1;
錯誤:ERROR 1690 (22003): BIGINT UNSIGNED value is out of range in '(cast(0 as unsigned) - 1)'
 
#若想得到負值而不報錯, 啓用該模式
SET sql_mode='NO_UNSIGNED_SUBTRACTION';
select cast(0 as unsigned) - 1;
+-------------------------+
| cast(0 as unsigned) - 1 |
+-------------------------+
|                      -1 |
+-------------------------+
 
 
======================================================================
【ONLY_FULL_GROUP_BY】
聚合語句安裝標準寫法,如 oracle sqlserver 一樣。
======================================================================
--	drop table test;
create table test(name varchar(10),value int);
insert into test values ('a',45),('a',42),('b',85),('c',65),('c',39);
 
#默認情況是可能會寫出無意義或錯誤的聚合語句:
SET sql_mode='';
select * from test group by name;
select value,sum(value) from test group by name;
 
#使用該模式後,寫法標準
SET sql_mode='ONLY_FULL_GROUP_BY';
select name,sum(value) from test group by name;
 
======================================================================
【PAD_CHAR_TO_FULL_LENGTH】
對於 charnchar 類型,默認以空字符填充,查詢時自動去掉空字符。
啓用該模式後,查詢時空字符保留。
======================================================================
--	drop table test;
create table test(c1 char(10),c2 nchar(10));
insert into test values ('aaa','bbb');
 
SET sql_mode='';
select length(c1),length(c2),char_length(c1),char_length(c2) from test;
+------------+------------+-----------------+-----------------+
| length(c1) | length(c2) | char_length(c1) | char_length(c2) |
+------------+------------+-----------------+-----------------+
|          3 |          3 |               3 |               3 |
+------------+------------+-----------------+-----------------+
 
SET sql_mode='PAD_CHAR_TO_FULL_LENGTH';
select length(c1),length(c2),char_length(c1),char_length(c2) from test;
+------------+------------+-----------------+-----------------+
| length(c1) | length(c2) | char_length(c1) | char_length(c2) |
+------------+------------+-----------------+-----------------+
|         10 |         10 |              10 |              10 |
+------------+------------+-----------------+-----------------+
 
 
======================================================================
【NO_DIR_IN_CREATE】
創建表分區時,忽略命令 INDEX DIRECTORY 和 DATA DIRECTORY。用於副本示例中的選項。
======================================================================
 
SET sql_mode='';
 
create table test(id int)
partition by range(id)(
	partition p0 values less than (5),
	partition p1 values less than maxvalue
);
 
 
SET sql_mode='NO_DIR_IN_CREATE';
 
create table test(id int)
ENGINE=MyISAM
partition by range(id)(
	partition p0 values less than (5)
		DATA DIRECTORY = 'E:/AAA/P0/data'  
		INDEX DIRECTORY = 'E:/AAA/P0/idx', 
	partition p1 values less than maxvalue
		DATA DIRECTORY = 'E:/AAA/P1/data'  
		INDEX DIRECTORY = 'E:/AAA/P1/idx'
);
 
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