Sql queries 10 pieces of data for each category

a table 

a_id name 
1    1

2    2

3    3

4    4

5    5

b table 

b_id name a_id
1    a    1

2    b    1

3    c    1

4    d    2

5    e    2

how to write the sql statement to query 10 pieces of data for each category

find an array structure similar to the following: 

array(
    array(
        "a_id"=>1,
        "a_name"=>1
        "b_list"=>array{
            array(
                "b_id"=>1,
                "b_name"=>a,
                "a_id"=>1,
            ),
            
            array(
                "b_id"=>1,
                "b_name"=>a,
                "a_id"=>1,
            ),
        }
    },
    array(
        "a_id"=>1,
        "a_name"=>1
        "b_list"=>array{
            array(
                "b_id"=>1,
                "b_name"=>a,
                "a_id"=>1,
            ),
            
            array(
                "b_id"=>1,
                "b_name"=>a,
                "a_id"=>1,
            ),
        }
    },
);

I"m not sure if this structure can be checked by mysql. How efficient is it? I want to toss about (A V A)

.
Php mysqli
Mar.24,2022

A way of using grouping and trickery
SELECT * FROM b WHERE b.id in (
SELECT GROUP_CONCAT (b.id) FROM an INNER JOIN b on a.id = b.aid GROUP BY a.id HAVING COUNT (*) < 11
)

The idea of

is to get 10 id of the b table of the group, then look it up in the model text, and finally get 10

of each group.

if it is up to date, sort it using

UNION query?

Previous: Is the model layer in the PHP framework equivalent to model+dao+service? in other languages?

Next: Use the typescript+vue project to get a red alert in the vscode editor?

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b315ee-2b0f0.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b315ee-2b0f0.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?