SQL SELECT 语句

王朝asp·作者佚名  2006-01-08
窄屏简体版  字體: |||超大  

SELECT

从数据库中检索行,并允许从一个或多个表中选择一个或多个行或列。虽然 SELECT 语句的完整语法较复杂,但是其主要的子句可归纳如下:

SELECT select_list

[ INTO new_table ]

FROM table_source

[ WHERE search_condition ]

[ GROUP BY group_by_expression ]

[ HAVING search_condition ]

[ ORDER BY order_expression [ ASC | DESC ] ]

可以在查询之间使用 UNION 运算符,以将查询的结果组合成单个结果集。

语法

SELECT statement ::=

< query_expression >

[ ORDER BY { order_by_expression | column_position [ ASC | DESC ] }

[ ,...n ] ]

[ COMPUTE

{ { AVG | COUNT | MAX | MIN | SUM } ( expression ) } [ ,...n ]

[ BY expression [ ,...n ] ]

]

[ FOR { BROWSE | XML { RAW | AUTO | EXPLICIT }

[ , XMLDATA ]

[ , ELEMENTS ]

[ , BINARY base64 ]

}

]

[ OPTION ( < query_hint > [ ,...n ]) ]

< query expression > ::=

{ < query specification > | ( < query expression > ) }

[ UNION [ ALL ] < query specification | ( < query expression > ) [...n ] ]

< query specification > ::=

SELECT [ ALL | DISTINCT ]

[ { TOP integer | TOP integer PERCENT } [ WITH TIES ] ]

< select_list >

[ INTO new_table ]

[ FROM { < table_source > } [ ,...n ] ]

[ WHERE < search_condition > ]

[ GROUP BY [ ALL ] group_by_expression [ ,...n ]

[ WITH { CUBE | ROLLUP } ]

]

[HAVING <search_condition>]

 
 
 
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