|
end as ttt
from table_name ; ------使用case函数
select table1.col1,table2.col2 from table1
[CROSS JOIN table2] | -----笛卡儿连接
[NATURAL JOIN table2] | -----用两个表中的同名列连接
[JOIN table2 USING (column_name)] | -----用两个表中的同名列中的某一列或几列连接
[JOIN table2
ON (table1.col1=table2.col2)] |
[LEFT|RIGHT|FULL OUTER JOIN table2 ------相当于(+)=,=(+)连接,全外连接
ON (table1.col1=table2.col2)]; ------SQL 1999中的JOIN语法;
example:
select col1,col2 from table1 t1
join table2 t2
on t1.col1=t2.col2 and t1.col3=t2.col1
join table3 t3
on t2.col1=t3.col3;
select * from table_name where col1 < any (select col2 from table_name2 where continue group by col3);
select * from table_name where col1 < all (select col2 from table_name2 where continue group by col3);
insert into (select col1,col2,col3 form table_name where col1>; 50 with check option) values (value1,value2,value3);
上一页 [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] ... 下一页 >> 更多精彩：学习网->http://www.haohao888.com.cn 网络编程->http://www.51wlpc.com 电脑设备->http://www.xpmaster.cn
|
