doucuo4413 2015-09-25 10:46
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MySQL如何仅从第一个表而不是第二个表限制来自JOIN-Query的行数?

I have a two Tables one with Countries and second with Cities.

First Table is Countries

country_id | country_name

Second Table is Cities

country_id | city_id | city_name

I want to limit amount of queries from second Table to 3 Cities. Because one Country have a lot of Cities. I need only 5 Cities.

My Query:

$query = “SELECT c.country_name, p.city_name FROM (SELECT * FROM Cities LIMIT 3) AS p LEFT JOIN Countries as c ON p.county_id = c.county_id”;ter code here

$result = mysqli_query($db, $query);

$my_array = array();

while($row = mysqli_fetch_assoc){
 array_push($my_array, $row);
}

If I fill $my_array i get 3 results from Database

My output:

[0] => Array ( [country_name] => Country 1 [city_name] => City 1 )

[1] => Array ( [country_name] => Country 1 [city_name] => City 2 )

[2] => Array ( [country_name] => Country 1 [city_name] => City 3 )

I need something like this


County 1
-----------------------
City 1 of Country 1
City 2 of Country 1
City 3 of Country 1
City 4 of Country 1
City 5 of Country 1

County 2
-----------------------
City 1 of Country 2
City 2 of Country 2
City 3 of Country 2
City 4 of Country 2
City 5 of Country 2

County 3
-----------------------
City 1 of Country 3
City 2 of Country 3
City 3 of Country 3
City 4 of Country 3
City 5 of Country 3

What I do wrong? I use MySQL 5.6.26

Thank you.

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1条回答 默认 最新

  • dongyou6795 2015-09-25 11:00
    关注

    Like that?

    SELECT city_id, city_name FROM Cities AS p LEFT JOIN Countries AS c ON c.country_id = p.country_id WHERE c.country_id = 'id' LIMIT 0,5
    
    评论

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