Question

是否有MYSQL LIMIT关键字的ANSI SQL替代？

LIMIT关键字限制SELECT返回的行数，例如：

SELECT * FROM People WHERE Age > 18 LIMIT 2;

返回2行。

SELECT * FROM People WHERE Age > 18 LIMIT 10, 2;

在前10行后返回2行。

Answer 1

this shows the different ways:

-- DB2
select * from table fetch first 10 rows only 
-- Informix 
select first 10 * from table 
-- Microsoft SQL Server and Access 
select top 10 * from table 
-- MySQL and PostgreSQL 
select * from table limit 10 
-- Oracle 
select * from (select * from table) where rownum <= 10

Answer 2

不在SQL：1999。

您可以在以后的标准中使用两种可能的方法，在当今的DBMS中通常支持水平较低。

在SQL：2008中，您可以使用DB / 2语法：

SELECT * FROM things
ORDER BY smell
FETCH FIRST n ROWS ONLY

这仅适用于“LIMIT n”而不适用于扩展的“LIMIT m，n”偏移语法。在SQL：2003中，您可以使用窗口函数，它可以支持扩展语法但是是超级PITA：

SELECT * FROM (
    SELECT *, ROW_NUMBER() OVER (ORDER BY smell) AS rn,
    FROM things
)
WHERE rn<=n -- or rn BETWEEN m+1 AND m+n

您今天通常会使用特定于DBMS的方法。

Answer 3

另见http://en.wikipedia.org/wiki/Select_(SQL)#FETCH_FIRST_clause

SELECT * FROM T LIMIT 10 OFFSET 20 -- Netezza, MySQL, PostgreSQL (also supports the standard, since version 8.4), SQLite, HSQLDB, H2

SELECT * from T WHERE ROWNUM <= 10 -- Oracle (also supports the standard, since Oracle8i)

SELECT FIRST 10 * from T -- Ingres

SELECT FIRST 10 * FROM T order by a -- Informix

SELECT SKIP 20 FIRST 10 * FROM T order by c, d -- Informix (row numbers are filtered after order by is evaluated. SKIP clause was introduced in a v10.00.xC4 fixpack)

SELECT TOP 10 * FROM T -- MS SQL Server, Sybase ASE, MS Access

SELECT TOP 10 START AT 20 * FROM T -- Sybase SQL Anywhere (also supports the standard, since version 9.0.1)

SELECT FIRST 10 SKIP 20 * FROM T -- Interbase, Firebird

SELECT * FROM T ROWS 20 TO 30 -- Firebird (since version 2.1)

SELECT * FROM T
WHERE ID_T > 10 FETCH FIRST 10 ROWS ONLY -- DB2

SELECT * FROM T
WHERE ID_T > 20 FETCH FIRST 10 ROWS ONLY -- DB2 (new rows are filtered after comparing with key column of table T)

Answer 4

我不相信。我所知道的所有数据库都使用特定于供应商的关键字来实现该功能。

Answer 5

添加到@ jle的answer：

SQLite支持LIMIT（MySQL / PostgreSQL）
InterBase / Firebird支持SELECT FIRST和SKIP（如Informix）

另见Emulate MySQL LIMIT clause in Microsoft SQL Server 2000

Answer 6

HSQL / H2使用像MySQL这样的LIMIT

Answer 7

让我在这里链接一个相关的SO问题，great answer by Lukas Eder和另一个good answer by bobince：

How universal is the LIMIT statement in SQL?

编辑：一些更好的参考链接，值得在类似案例中查看：

The jOOQ user manual page on the LIMIT clause

Lukas Eder's answer。

是否有MYSQL LIMIT关键字的ANSI SQL替代品？

7 个答案: