[ ORDER BY expression [ ASC | DESC | USING operator ] [ NULLS { FIRST | LAST } ] [, ...] ] [ LIMIT { count | ALL } ] [ OFFSET start [ ROW | ROWS ] ] [ FETCH { FIRST | NEXT } [ count ] { ROW | ROWS } ONLY ] [ FOR { UPDATE | NO KEY UPDATE | SHARE | KEY SH...
OFFSET start { ROW | ROWS } FETCH { FIRST | NEXT } [ count ] { ROW | ROWS } ONLY 其中,OFFSET 表示跳过指定的 start 行数, 默认为 0;FETCH 表示最多返回 count 行结果,默认为 1;ROW 和 ROWS 是同义词,FIRST 和 NEXT 是同义词;ONLY 表示不返回更多的数据。 例如,以下语句返回了分数最高的 2...
SELECTfirst_name,last_name,salaryFROMemployeesorderbysalarydescOFFSET10ROWSfetchfirst10rowsonly; OFFSET表示先忽略掉多少行数据,然后再返回后面的结果。ROWS也可以写成ROW。对于应用程序而言,只需要传入不同的OFFSET偏移量和FETCH数量,就可以在结果中任意导航。使用LIMIT加上OFFSET同样可以实现分页效果: SELECTfirst_name...
postgres=# \helpSELECTCommand:SELECTDescription:retrieve rows from a table or viewSyntax:[WITH[RECURSIVE]with_query[,...]]SELECT[ALL|DISTINCT[ON(expression[,...])]][*|expression[[AS]output_name][,...]][FROMfrom_item[,...]][WHEREcondition][GROUPBYgrouping_element[,...]][HAVINGcondition[...
FETCHFIRST3ROWSONLY; id --- 1 2 3 (3rows) Many of you may never have used or seen this kind of syntax before, but this is actually the “correct” way to handleLIMIT. However, there is more: What happens ifNULLis used inside yourLIMITclause? The result might surprise you: 1...
我们先看一下完整的FETCH和LIMIT语法: SELECT column1, column2, ... FROM table [WHERE conditions] [ORDER BY column1 ASC, column2 DESC, ...] [OFFSET m {ROW | ROWS}] [FETCH { FIRST | NEXT } [ num_rows] { ROW | ROWS } ONLY]; SELECT column1, column2, ... FROM table [WHERE ...
[ FETCH { FIRST|NEXT} [ count ] { ROW |ROWS } ONLY ] [FOR{ UPDATE |NOKEY UPDATE | SHARE | KEY SHARE } [ OF table_name [, ...] ] [ NOWAIT | SKIP LOCKED ] [...] ] from_item 可以是以下选项之一: [ ONLY ] table_name [* ] [ [ AS ] alias [ ( column_alias [, .....
--1CREATEFUNCTIONnew_emp()RETURNSempAS$$SELECTtext’None’ASname,--注意类型转换1000.0ASsalary,25ASage, point ’(2,2)’AScubicle; $$ LANGUAGE SQL;--字段顺序和类型要和返回类型(此处是emp)保持一致--2CREATEFUNCTIONnew_emp()RETURNSempAS$$SELECTROW(’None’,1000.0,25, ’(2,2)’)::emp; ...
1. 2. 1.2.Oracle12C+ Oracle11g之前很难用,Oracle12C+与MySQL用法格式一样了,只是语法关键字不一样,而且比较啰嗦 语法 OFFSET是偏移量,常数,不写默认为0,常用于分页。 FETCH NEXT 1 ROWS 等同于 FETCH FIRST 1 ROW。 only只返回指定的量,with ties 返回和最后一条数据相同的数据。
{ FIRST | LAST } ] [, ...] ] [ LIMIT { count | ALL } ] [ OFFSET start [ ROW | ROWS ] ] [ FETCH { FIRST | NEXT } [ count ] { ROW | ROWS } ONLY ] [ FOR { UPDATE | NO KEY UPDATE | SHARE | KEY SHARE } [ OF table_name [, ...] ] [ NOWAIT | SKIP LOCKED ]...