自增长字段id重新排序
ALTER TABLE ` table_name` DROP ` id ` ;
ALTER TABLE ` table_name` ADD 'id' mediumint( 6) PRIMARY KEY NOT NULL AUTO_INCREMENT FIRST;
truncate table 表名
互换表中两列数据
update [ table1] as a, [ table1] as b set a.[ column1] = b.[ column2] , a.[ column2] = b.[ column1] where a.id= b.id;
导出表,导出库,导入数据
mysqldump - u root - p [ database_name] [ table_name] > / xx/ xx/ xxx. sql ;
mysqldump - uroot - p
mysql - u root - p;
use datebase;
source / xx/ xx/ xx. sql ;
将查询结果保存至新表,导出查询结果
insert into tab1 select * from tab2;
create table tab1 as select * from tab2;
SELECT {} from [ table_name] where 条件 into outfile './xx/xx/x.sql' ;
mysqldump - u用户名 - p - c
数据库日期函数
select to_char( sysdate, 'yyyy-mm-dd hh24:mi:ss' ) as nowTime from dual;
select to_char( sysdate, 'yyyy-mm-dd' ) as nowTime from dual;
select to_char( sysdate, 'yyyy' ) as nowYear from dual;
select to_char( sysdate, 'mm' ) as nowMonth from dual;
select to_char( sysdate, 'dd' ) as nowDay from dual;
select to_char( sysdate, 'hh24' ) as nowHour from dual;
select to_char( sysdate, 'mi' ) as nowMinute from dual;
select to_char( sysdate, 'ss' ) as nowSecond from dual;
select {} from table_name where 日期字段 >= to_char( sysdate- 1 , 'yyyy-mm-dd' )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 0 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 1 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 2 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 3 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 4 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 5 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 6 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 7 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 8 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 9 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 10 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 11 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 12 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 13 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 14 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 20 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 21 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 22 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 23 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 24 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 25 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 100 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 101 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 102 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 103 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 104 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 105 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 106 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 107 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 108 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 109 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 110 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 111 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 112 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 113 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 114 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 120 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 121 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 126 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 130 )
Select CONVERT ( varchar ( 100 ) , GETDATE( ) , 131 ) : 18 / 04 / 1427 10 :57 :49 :920 AM
select {} from {} where date_column between '2019-1-1' and '2019-2-1' ;
今天的所有数据:select * from 表名 where DateDiff( dd, datetime 类型字段, getdate( ) ) = 0
昨天的所有数据:select * from 表名 where DateDiff( dd, datetime 类型字段, getdate( ) ) = 1
7 天内的所有数据:select * from 表名 where DateDiff( dd, datetime 类型字段, getdate( ) ) <= 7
30 天内的所有数据:select * from 表名 where DateDiff( dd, datetime 类型字段, getdate( ) ) <= 30
本月的所有数据:select * from 表名 where DateDiff( mm, datetime 类型字段, getdate( ) ) = 0
本年的所有数据:select * from 表名 where DateDiff( yy, datetime 类型字段, getdate( ) ) = 0
select str_to_date( '08/09/2008' , '%m/%d/%Y' ) ;
select str_to_date( '08/09/08' , '%m/%d/%y' ) ;
select str_to_date( '08.09.2008' , '%m.%d.%Y' ) ;
select str_to_date( '08:09:30' , '%h:%i:%s' ) ;
select str_to_date( '08.09.2008 08:09:30' , '%m.%d.%Y %h:%i:%s' ) ;
select date_format( '2008-08-08 22:23:01' , '%Y%m%d%H%i%s' ) ;