《與mysql零距離接觸》視屏學習筆記

1、數據表的增刪改查操作(crud)：

對於表：

      增：create  table  XXXX

      刪：drop table XXXX

      改：alter table XXXX rename to XXXX

      查：select * from XXXX

對於行：

      增：insert  into  XXXX(xxxx) values (xxxx)

               insert into XXXX set xxxx=xx , xxxx=xx

      刪：delete from XXXX where xxxx

      改：update table set xxxx=xxxx where xxxx=xxxx

      查：select xxxx from XXXX

 對於列：

      增：alter  table  XXXX add xxxx()

      刪：alter table XXXX drop xxxx

      改：alter table XXXX change xxxx xxxx xxxx

               alter table XXXX modify xxxx xxxx

      查：show columns from XXXX

2、運算符與函數

字元函數

Concat()                  select concat('hha','-','hdf')

Concat_ws()           select concat_ws('=','A','B','C')

Format()                  select format(125060.752,2)

Lower()                    select lower('HIIHO')

Upper()                    select upper('fsfds')

Left()                        select left('fsfds',2)

Right()                      select right('fsfds',2)

Length()                   select length(' fsfds ')

Ltrim()                      select ltrim(' fsfds ')

Rtrim()                     select rtrim(' fsfds ')

Trim()                       select trim(' fsfds ')

                                  select trim(leading '?' from ' fs?fds ')

                                  select trim(trailing '?' from ' fs?fds ')

                                  select trim(both '?' from ' fs?fds ')

Substring()              select substring(' fsfds ',2,3)

                                  select substring(' fsfds ',2)

Like                           select 'myufsd' like 'm%'

                                  select * from test where first_name like '%1%%' escape '1'

                                  %代表任意個字元

                                   _代表任意一個字元

Replace()                 select replace('fsgasgsfa','s','t')

3、數值運算符

Div                             整數除法

4、比較運算符合函數

Not  between   and

Not  in

5、時間和日期函數

Now()

Curdate()

Curtime()

Date_add()

Datediff()

Date_format()

6、信息函數

Connection_id()

Datebase()

Last_insert_id()

User()

Version()

7聚合函數

。。。

8、加密函數

Md5()

Password()