SQLÓï¾ä

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    1£©´´½¨Êý¾Ý¿â£¨create£©£ºcreate database database-name;
           eg. create database test;
    2£©É¾³ýÊý¾Ý¿â£ºdrop database dbname;
          eg.drop database test;
    3£©´´½¨ÐÂ±í£ºcreate table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..);
         eg.¸ù¾ÝÒÑÓÐµÄ±í´´½¨Ð±íµÄÀý×Ó£ºcreate table tab_new like tab_old£»create table tab_new as select col1,col2… from tab_old definition only;
    4£©É¾³ý±í£ºdrop table tabname;
    5£©Ôö¼ÓÁУºalter table tabname add column col type;
    6£©Ìí¼ÓÖ÷¼ü£º alter table tabname add primary key(col) ;
    7£©É¾³ýÖ÷¼ü£ºalter table tabname drop primary key(col) ;
    8£©´´½¨Ë÷Òý£ºcreate [unique] index idxname on tabname(col….) ;
    9£©É¾³ýË÷Òý£ºdrop index idxname;  ×¢£ºË÷ÒýÊDz»¿É¸ü¸ÄµÄ£¬Ïë¸ü¸Ä±ØÐëɾ³ýÖØн¨£»
   10£©´´½¨ÊÓͼ£ºcreate view viewname as select statement;
2. Êý¾Ý²Ù×ÝÓïÑÔ£¨DML£©
    1£©²éѯÓï¾ä£¨select£©
   eg1. select * from table1 where field1 like '%value1%';
   eg2. select * from table1 order by field1,field2 [desc];
   eg3. select count as totalcount from table1;
  eg4. select sum(field1) as sumvalue from table1;
  eg5. select avg(field1) as avgvalue from table1;
  eg6. select max(field1) as maxvalue from table1;
  eg7. select min(field1) as minvalue from table1;
  eg8. select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c;£¨×¢£º´ËΪ×óÍâÁ¬½Ó£¬½á¹û¼¯ÖаüÀ¨Á¬½Ó±íµÄÆ¥ÅäÐУ¬Ò²°üÀ¨×óÁ¬½Ó±íµÄËùÓÐÐУ©
   2£©²åÈëÓï¾ä£¨insert£©
  insert into table1(field1,field2) values(value1,value2);
  3£©É¾³ýÓï¾