mysql - How to retrieve multiple tags from a database? -


alright, have done research , found out normalized articles , tags table should this:

articles table:  article_id | article_text  tags table: tag_id | tag_text  article-tag table: article_id | tag_id

now, try this: let's searching 3 tags example, "asp.net", ".net", "c#". easy retrieve articles has these tags. don't want this. want retrieve articles has exactly these 3 tags or any 2 or 1 of them not articles 4 or more tags including them. don't want search result "asp.net", ".net", "c#", "ruby". want following tagged articles:

"asp.net", ".net", "c#"  .net", "c#"  "asp.net", ".net"  "asp.net", "c#"  "c#"  "asp.net"  ".net"

what right mysql query that?

i'm thinking self join might way. if querying 3 tags, join article-tag table 3 times, example. i'm not sure how scale, though.

update: approach need second query exclude matches > 3 tags.


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