哪些数据库供应商支持Aggregate Rank()函数?

据我所知,目前(2018年4月),只有两个数据库作为聚合实现了此功能:

神谕 --&燃气轮机;演示--> http://sqlfiddle.com/#!4/74fa70/2

SELECT rank( 2 ) within group (order by x) as rank_x FROM qwe;

SELECT rank( 2 ) within group (order by y) as rank_y FROM qwe;

SELECT rank( 2, 7 ) within group (order by x,y)  as rank_x_y FROM qwe;

| RANK_X |
|--------|
|      5 |

| RANK_Y |
|--------|
|      2 |

| RANK_X_Y |
|----------|
|        7 |

PostgreSQL --&燃气轮机;演示--> http://sqlfiddle.com/#!17/74fa7/5

从qwe中选择group(order by x)中的rank(2)作为rank\u x;

从qwe中选择group(order by y)中的rank(2)作为rank\u y;

从qwe中选择组内的秩(2,7)(按x,y排序)作为秩x\u y;

|秩\u X|
|--------|
|5|

|排名Y|
|--------|
|2|

|排名\u X\u Y|
|----------|
|7|

分析版本 rank() over ,除了Oracle和PostgreSQL之外,SQL Server、DB2、MySql(将在即将发布的版本中)中也已实现。

这两个演示基于以下示例数据:

CREATE TABLE qwe(
  x int, y int
 );

insert into qwe values(1,1);
insert into qwe values(1,2);
insert into qwe values(1,3);
insert into qwe values(1,4);
insert into qwe values(2,5);
insert into qwe values(2,6);
insert into qwe values(3,7);