Difference between Top and Limit Keyword in SQL

A quick Question. Suppose I have the following two queries:

SELECT TOP 2 * FROM Persons;

and

SELECT * FROM Persons limit 2;

I want to know the difference between the execution of the above 2 queries? Basically, I want to know when should I use the limit keyword and when it is ap开发者_JAVA技巧propriate to use the top keyword. Also, How does the database return results based on the above 2 queries.

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If you are using SQL Server use TOP. if you are using MySQL or PostgreSQL use LIMIT!

AFAIK there is no product that currently supports both. Here's one list of current implementations and here's another (covers more products but in less detail)

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As stated in my comment for Martin Smith's answer above, there are products that support both, LIMIT and TOP (as you can see here). The difference is that TOP only selects the first n records, but LIMIT allows the definition of an offset to retrieve a specific range of records:

SELECT * FROM ... LIMIT 5 OFFSET 10

This statement selects the 5 records, after skipping 10 records and this isn't possible with TOP.

The example I posted is only checked against the DBS I linked above. I didn't check a SQL standard, because of a lack of time.

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TOP & LIMIT both work on amazon Redshift

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limit works on MySQL and PostgreSQL, top works on SQL Server, rownum works on Oracle.

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There is no difference. The TOP and LIMIT keywords function identically, and will return the same thing.

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The DISTINCT command and the TOP command can't work together.

The DISTINCT command and the LIMIT command do work together.

So if you are using DISTINCT you must use LIMIT.

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The difference between top and limit is, top only work with single table where as limit can work with join as well

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one big mistake, LIMIT is slowly because select is return full and then database server return only limited data. When it is posible used to TOP.