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Mysql ?? ??? ??, ??, ??

??? ???? ?? ???? ?? ??? ???? ??????. ? ????? ?? ??? ???? ?? ?? ??? ?????.

money?? ??? ??? ??????.

???? ???? ???? ??? ????.

CREATE TABLE money (
     id INT NOT NULL AUTO_INCREMENT ,
     username VARCHAR(50) NOT NULL ,
     balance FLOAT NOT NULL ,
     province VARCHAR(20) NOT NULL ,
     age TINYINT UNSIGNED NOT NULL ,
     sex TINYINT NOT NULL ,
     PRIMARY KEY (id(10))
) ENGINE = InnoDB CHARACTER SET utf8;

??? ??? ???? ??? ?? ?????:

idusernamebalanceprovinceagesex
1 ???? 120.02???291
2???260.23??40 0
3????150.86 Shandong40 1
4Jing Boran810Liaoning271
5Li Bingbing 20.15???? 430
6?? 313Shandong631
7Yang Mi123Beijing 300
8??? 456Beijing29 1
9Liu Yan23.4Hunan360
10Zhao Benshan3456??? 631
11王峰 34.32Beijing441
12Guo Degang 212Tianjin431

??:
balance? ??? ?????.
province? ??? ?????.

?? ??

Category??? ??
?? ??select * from table;
??? * from Money;
?? ?? ? ?? ???? ?? ??? ?? ?? ??

??: "*"? ?? ??? ???? ???? ?? ??????. ? ?? ?? ??? ?????.

mysql> select * from Money;
+----+---- ---- ---+---------+---------+-----+
| ??? | ?? |
+----+------------+----------+------------+--- ---+ -----+
| 120.02 | ??? | 40 | 1 |
| 810 | ??? | 20.15 | ?? 6 | | ?? | 30 | 456 | ?? | 36 | ??? | 1 |
| 34.32 | ??? 1 | --------+------ -----+------------+------+------+
12? ? ?? (0.00?)

?? ?? ??




????


??? ?? 語(yǔ) ?? ?? ????? ?? ?? ID, ??? ??, ?? ??; ??? ??, ?? ?? ?? 
           ?? 
          mysql> ID, ??? ??, ?? ??;
          +----+----------+----------+
          | ID |
           +----+------------+
          | 1 | ???? | 260.23 |
          | ? ??? | 
          | 5 | ??? | 313 |
          | 8 | 
          | 23.4 | 10 | ???? | 34.32 |
          | 212 | ---+------- --+
          ??? 12? ?(0.00?)

          ???? ?? ???? ?? ?? ?? ?? ??




          category
          ??? ??
          +------+| 27 || | 63 || 30 || 36 || 44 |8?(0.00?)??? ?? whereselect field from Table where ??;
           basic syntax afectax tail?? ??? ??? ??????; ??? ??? ?? ?? ?? ??;| 29 |
          +---------+
          ??? ?? 
          ?? ??

          Example

          select * from Money where age = 29;



          ?? ??

          ?? ??? 29? ?? ??? ?????. ?? ???



          mysql> ?? = 29? ??? * ??;
          +----+----------+---------+--------- - +------+----+
          | ??? | ?? |
          +--------+--- - ----+--------+----+
          | 1 | ???? 120.02 | ??? | | 456 | ??? | 29 | 1 |
          +----+----------+--------+- - ---+------+
          2? ??(0.00?)
          where? ?? ? ?? ??
          ?? ?????? ?? ???? ?? ??? ?????. ?? ??? where ?? ??? ??? '='???. 
          ?? >, <, >=, <=, !=; 
          symbolExplanation>>? ?? ?? ???? ??? ?? ????. ; <?? ?? >=?? ??? ?? <=?? ??? ??  !=??? = ?? 
          ?? ???
          ?? ??? or ? ?? ?? ???? ???? ?? ?? ?? ??? ??? ?? ????
          SymbolExplan ationoror andand
           
           
           ?? ??? ?? ???????. 
          Type???? ??? * ? ID? <10?????? ??? 10?? ?? ID? ???? ??='Hubei'
          mysql> '???';
          
 +------+------------+---------+----------+------+----- +
          
 | ??? | ?? |
 +------+------------+---------+----------+------+----- +
          
 1 | ???? 120.02 |
 +------+------------+---------+----------+------+----- +
          
 1?(0.00?)


          ?? ?? ??
          Category??? ???? ???? ?? ???? ????? ?? ???  ?? ???? ????? ID, ??? ??, ?? ??;?? ???? ???? ID, ??? ??, ?? ??? ???? ??? ?? ?????? ??
          ??? ???? ???: 
           
          mysql> ?? ???? ????? ID, ??? ??, ?? ??;+----+------------+---------+
          ???  ?? 
          asc????, ?? ??? ? ???(???) 
          desc ????, ?? ???? ?? ?? ? ?? ??? order by? ?????. ??? desc ? asc? ?? ??? ??????. desc? ???? ?????? ???? ?? ????, asc? ?????? ???? ?? ?????. ???? ?? ??? ???? ?????? ?????. 
          | ??? ?? |
          +---------+---------+
          | 10 | ???? | 810 |
           | 8 | ?? | 260.23 |
          | 1 | ???? | 11 | ?? | 23.4 |
          | 20.15 | -+-- -------+
          ?? ? 12? ?(0.00?)

          ?? ?? ??

          order by ??? ??? ?? ?? ?? ??? ? ? ??? ??? ?? ??? ??? ?????. ??? ????. ??? ?? ??? ?? ??? ?? ??? ?? ?? ??? ? ?? ?? ??? ?? ?????. 




          Category

          ??? ??


          ?? ??
          ????? ?? ?? ?? 1 ?? ??? ?? ??,... ...Field n desc|asc;?? ??
          * ??: ? ?? ??? ?? ??? ???? ?? ??. ? ?? ?? ?? ??? ???? ????. ? ?? ? ?? ??? ???? ????. *
          mysql> ?? ??, ?? ?????? ??? ??, ??? ??, ??? ?????.
          
 +----+------------+---------+
          
 | ??? | ?? |
          
 +----+------------+---------+
          
 10 | ???? |
 4 | ??? 810 |
          
 8 | 456 |
          
 6 | ?? 313 |
          
 2 | ??? 260.23 |
          
 12 | ??? |
 3 | ???? 150.86 |
          
 7 |?? 123 |
          
 1 | ???? 120.02 |
          
 11 | ?? 34.32 |
          
 9 | ??? |
 5 | ??? 20.15 |
          
 +----+------------+---------+
          
 ??? 12? ?(0.00?)


          ?? ?? ??
          ?? ?? ??? ?? ??? ?? ??? ?? ??? ????? ?? ???? ???? ?? ?? ?? ?????. 
          ?   id, ??? ??, ??? ?? desc, age asc? ?????? ?? 
           ?? ???? id, ??? ??, ?? ??? ???? ??? ?? ?????? ?????. ??? ?? ????? age? ???? ?????? ?????
          ??????? ???? ???? ???? ?? ??;Example ?? 5?? ID, ??? ??, ?? ??;  ? ?? ?? 5?? ??? ??
          mysql> ?? ?? 5?? * ??;
          +----+------------+----------+---------- - +------+------+
          | ??? | ?? |
          +-------+--- - ----+----------+-----+
          | 1 | ???? 120.02 | ? | ????? | 43 | 0 | ---+--- ---+
          5? ??(0.00?)

          ?? ?? ?? ? ??


          Category
           
          ??? ???? ???? ?? ?? ??? ??? ?? ??? ?? QuantityExampleselect id,username, Balance from Money order by Balance desc Limit 5;?? ?????? ??, ?? 5?? ??? ??? ??+----+------------+---------+| ??? | ??? ?? | ?? |+---------+---------+
            mysql> ID, ??? ??, ????? ?? ?? ?? 5;
          | 810 |
           | 6 | ?? | 260.23 |
          +-------+ ------ -+
          5? ??(0.00?)

          ?? ?? ?? ??

          0?? ???? 3?? ???? ???? ?????. ? ?? ????? 3? ???? ? ???? ????. 6?? ????? 4?? ???? ????? ??? ?? ???? 

          ?? ?? ?? ?? ??? ???? ???. 

          ????
          ??? ??
          ??? ??
          ??: ? ?? ???? 0???. 
          mysql> ID, ??? ??, ?? ?? 0,3;
          ? ?????.
 +----+------------+---------+
          
 | ??? | ?? |
          
 +----+------------+---------+
          
 1 | ???? 120.02 |
          
 2 | ??? 260.23 |
          
 3 | ???? 150.86 |
          
 +----+------------+---------+
          
 3? ?? (0.00?)
          3??? 3? ? ???? ? ????? 
          mysql> ID, ??? ??, ?? ?? 3,3;
          ? ?????.
 +----+------------+---------+
          
 | ??? | ?? |
          
 +----+------------+---------+
          
 4 | ??? 810 |
          
 5 | ??? 20.15 |
          
 6 | ?? 313 |
          
 +----+------------+---------+
          
 3? ??(0.00?)
          ? ????? ?? ?????? ???? ?????. 
          ???? 10?? ???? ??? ??: 
          ??? 1? ?? 0,10
          ??? 2? ?? 10,10
          ??? 3? ?? 20,10
          ?... ...
          ?? ?? ?? 
          1. ? ??? ?? ?? ??? ??? ?? ???? 
          2. ??? ????? ?? ?? ??? ???? ???? ??? ?????? 
          3. ???? ??? ?? ??? ?? ??? ??? ?? ???? 
          4. ?? ???? ??? ?? ??? ??? ?? ???? 
          ?? ????? ???? ? ?? ?? ??? ????. 
          ?? ??????? ?? ?? ?? ???, ??
          ?? ?? 0, 3?? ID, ??? ??, ?? ?? ; 
          ? ?? ????? ? ?? ???? ?????
           
           ??  ?? 
          sumsum 
          count?? ?? 
          max ??? 
          min???
          avgAverage
          ??: ?? ?? mysql ??? ??? ? ??? ?? ?? ????. ??? ?? ????? ???? ?? ?? ?? ?? ?????? ?? ???? ??? ?? ?? ?? ??? ??? ????. MySQL ??? ???? ?? ?? ??? ??? ??? ?? ?? ?? ??? ???? ??? ?? ??? ??? ??? ????. 
          ??????? ??
          ?? ??select function(field) from table
          Exampleselect count(id) from Money 
           
          ?? ?  ?? ???? ? ID ?? ?????
          mysql> ??? ??(id) ??;
          
 +----------+
          
 | ??(ID) |
          
 +----------+
          
 12 |
          
 +----------+
          
 1? ??(0.00?)
          ??? ??? ??? ?? ????! as ???? ?????. 
          mysql> ??? ??? count(id)? ?????.
          
 +---------+
          
 |?? |
          
 +---------+
          
 12 |
          
 +---------+
          
 1? ??(0.00?)
          ?? ?? ??
          mysql> ??? ??(??) ??;
          
 +---------+
          
 ??(??) |
          
 +---------+
          
 498.24833393096924 |
          
 +---------+
          
 1? ??(0.00?)
          ?? ??
          mysql> ??? ??(??) ??;
          
 +------+
          
 | ??(??) |
          
 +------+
          
 5978.980007171631 |
          
 +------+
          
 1? ??(0.00?)
          ?? ?? ??
          mysql> ??? ??(??) ??;
          
 +-------------+
          
 |??(??) |
          
 +-------------+
          
 3456 |
          
 +-------------+
          
 1? ??(0.00?)
          ?? ?? ??
          mysql> ??? ??(??) ??;
          
 +---------+
          
 |??(??) |
          
 +---------+
          
 20.149999618530273 |
          
 +---------+
          
 1? ??(0.00?)
          group by
          ???? ??? ??? ???? ???? ? ?? ? ????. ??? ??? ?????. ?, ??? ?????. ??? 
           ?? ? ???? ???
          mysql> ??? ?? ???? * ??;
          +----+------------+---------+--------- -+----+------+
          | ??? | ?? |
          +------+--- ------+--------+-----+
          | 7 | ??? 30 | Guo Degang | ?? | 0 |
          | 4 | ??? | 20.15 | --------------+-- -------+------------+------+------+
           
          ??? ???(??) ? ?:

          mysql> deptno ??, emp ???? deptno?? ??(1);
          +---------+------------+
          | ????(1) |
          +-------+
          | 1 | 1 |
          | 5 | 4 |
          +---------+--- -------+
          4? ??(0.04?)

          ? ?? ?? ???? ?????

           
          mysql> ??? ?? ???? ??(??), ?? ??;
          
 +------+------------+
          
 | ???(?) |
          
 +------+------------+
          
 3 | ??? |
          
 | 1 1 | ?? |
          
 3 |?? |
          
 1 1 |
 |??? |
          
 2 | ??? |
          
 | ????? |
          
 +------+------------+
          
 7? ??(0.00?)


          ??? ??

          ??? ??? ??? ?? ???? ????. ? ?? ???? ?? ???? ?????. 

           ?? ??? ???? ???? ??? ??? ?? ? ??? ???? ????. 
           
          Category??? ??
          ?? ??select * from table group by field with Rollup
          Exampleselect count(province),province from Money Group by Province with ?? ; 
          ?? ???? ?? ?? ??? ???
          ? ??? ??? ?? ?? ??? ?? ?? ?? ?? ?? 12?? NULL? ??? ????. 
          mysql> ??? ?? ??? ?? ???? ??(??) ??;
          
 +------+------------+
          
 | ???(?) |
          
 +------+------------+
          
 3 | ??? |
          
 | 1 1 | ?? |
          
 3 |?? |
          
 1 1 |
 |??? |
          
 2 | ??? |
          
 | ????? |
          
 12 |NULL |
          
 +------+------------+
          
 8? ??(0.00?)
          ?? ?? ??? ??????.
          having ?? where? ????? ? ? ??? ???? ????. 
          having? ??? ???? ??? ??? ??? ???? 
          Category??? ???? ??select * ????? ??? ?? ???? ???Examplecount(province)? ??? ?? ???? ? ???? >2;?? ???? ????? ??? ???? ??? ??? 2?? ? ???? ??? ?????
          mysql> ??? count(province)? ????, ???? ? ???? ??? >2;
          
 +---------+----------+
          
 | ?? |
          
 +---------+----------+
          
 3 | ??? |
          
 3 |?? |
          
 +---------+----------+
          
 2? ??(0.00?)
          SQL ?? ????
          ? ???? ??? ?? ?? ?? ??????. 
          ?? ?? ???? ? ? ?? ?????. ?? SQL ?? ???? ?? ??? ??? ????. 
          SELECT 
          
 [?? 1 [?? 1], [??(?? 2),]...?? n] 
          
 FROM ??? ??
          
 [WHERE ?? ??]
          
 [GROUP BY ??]
          
 [HAVING where_continition]
          
 [????]
          
 [?? ??]
          ??: []? ? ??? ?? ??? ??? ? ????. 
          ?? ??? ??? ?? ?????. 
          Keywords Description
          selectSelected columns
          fromtable
           
           ???? ??
           
           group by?? ??? ??? ?? grouping ??
          order bysort attribute
          limit?? ??? ??, ??? ?? ????
          ????? ?????. , ?? ??? ??(id, ??? ??, ??, ??)? ?????. id>1?? ??? 50?? ?? ???. ????? ??? ?????. ?????? ??? ID? ????, 3?? ??? ????? ?????. 
          ????? ??? ?? SQL ?? ???? ?? ??? ??? ????. 
          mysql> ?? 3;
          
 +------+------------+---------+----------+
          
 | ??? | ?? |
 +------+------------+---------+----------+
          
 12 | ??? 212 |
 7 | ?? |
 4 | ??? 810 |
          
 +------+------------+---------+----------+
          
 3? ?? (0.00?)


          					
				
			???? ??
			

			
          

				
          
			        
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          <?php
echo "Hello Mysql";
?>
          

				
			
          
			
          
			


		



















          
    

          














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