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Pure MySQL? ? ??? ??? ? ???? (?? ';' ??? ?? ??)
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Nov 01, 2024 am 12:03 AM

Can I Join Tables in MySQL Based on Values Separated by Semicolons?

Pure MySQL? ? ??? ??? ? ???? (?? ';' ??? ?? ??)

??:

';'? ???? ???? ?? ???? ?? ???? ????. (????)? ?? ?? ?????. ??? ???? ?? PHP? ?? ??? ??? ? ????. MySQL? ???? ?? ??? ? ?? ??? ?????

??:

?, ';'? ??? ? ????. ?? MySQL? ???? ?? ?? ?????. ??? ?? ??? ?? ??? ?????.

??? ???? ??? ??

??? ';' ??? ???? ??? ??? ????. ?? ?? ??? ???? ??? ? ????.

  1. ??? ???? 1?? ?? ?? ???? ??? ???? ?? ????? ???? ?????.
  2. COUNT_IN_SET ? VALUE_IN_SET? ?????. ??? ???? ?? ?? ???? ??? ?? ? ??? ???? ?????.
  3. ?? ??? ???? user_resource ???? ?? ??? ???? ?????. ??? ?? ??? ???? ? ??? ?? ?? ?????.

User_resource ???? ????? ??

<code class="sql">SELECT user_resource.user, 
       user_resource.resources,
       COUNT_IN_SET(user_resource.resources, ';') AS resources_count, 
       isequence.id AS resources_index,
       VALUE_IN_SET(user_resource.resources, ';', isequence.id) AS resources_value
FROM 
     user_resource 
     JOIN  integerseries AS isequence 
       ON  isequence.id <= COUNT_IN_SET(user_resource.resources, ';')
ORDER BY
       user_resource.user, isequence.id</code>

??? ???? ???? ??? ?? ??? ???

user_resource ???? ????? ??? ???? ???? ??? ??? ?? ? ????.

<code class="sql">SELECT user_resource.user, 
       resource.data

FROM user_resource 
     JOIN integerseries AS isequence 
       ON isequence.id <= COUNT_IN_SET(user_resource.resources, ';')

     JOIN resource 
       ON resource.id = VALUE_IN_SET(user_resource.resources, ';', isequence.id)      
ORDER BY
       user_resource.user,  resource.data</code>

?? ?? ? ??

user_resource ???:

user resources
user1 1;2;4
user2 2
user3 3;4

resource ???:

id data
1 data1
2 data2
3 data3
4 data4
5 data5

Normalizeduser_resource ???:

user resources resources_count resources_index resources_value
user1 1;2;4 3 1 1
user1 1;2;4 3 2 2
user1 1;2;4 3 3 4
user2 2 1 1 2
user3 3;4 2 1 3
user3 3;4 2 2 4

??(??? ??):

user data
user1 data1
user1 data2
user1 data4
user2 data2

? ??? ?????? ??? ?? ???? MySQL?? ???? ??? ? ?????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!

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