如何限制 PostgreSQLSELECT 中的行

You can use LIMIT just like in MySQL, for example:

SELECT * FROM users LIMIT 5;

Use the LIMIT clause or FETCH FIRST 10 ROWS

You could always add the OFFSET clause along with LIMIT clause.

You may need to pick up a set of records from a particular offset. Here is an example which picks up 3 records starting from 3rd position:

testdb=# SELECT * FROM COMPANY LIMIT 3 OFFSET 2;

This would produce the following result:

 id | name  | age | address   | salary
----+-------+-----+-----------+--------
3 | Teddy |  23 | Norway    |  20000
4 | Mark  |  25 | Rich-Mond |  65000
5 | David |  27 | Texas     |  85000

Full explanation and more examples check HERE

Apart from limit you could use Fetch First as well. Your question already had the answer

Select * from users FETCH FIRST 5 ROWS ONLY

On PostgreSQL, there are two ways to achieve this goal.

SQL Standard

The first option is to use the SQL:2008 standard way of limiting a result set using the FETCH FIRST N ROWS ONLY syntax:

SELECT
title
FROM
post
ORDER BY
id DESC
FETCH FIRST 50 ROWS ONLY

The SQL:2008 standard syntax is supported since PostgreSQL 8.4.

PostgreSQL 8.3 or older

For PostgreSQL 8.3 or older versions, you need the LIMIT clause to restrict the result set size:

SELECT
title
FROM
post
ORDER BY
id DESC
LIMIT 50