The question you're asking appears subjective and is likely to be closed.
I wasn't surprised when I saw above horrible warning while I was filling in title field.
I read almost every thread talking about friends of friends or mutual friends but I'm not sure I found the right solution that I want to do.
I'm sorry I'm not good at English nor SQL.
How can I find the right answer while being not good at both of languages?
I decided I have to ask. I won't let myself down for down-votes or any duplication warnings.
As I want the answer, I'll write down as sincerely as possible for any further similar problems can be helped.
I have a table for friend relations.
FRIEND (TABLE)
-----------------------------------
PLAYER_ID(PK,FK) FRIEND_ID(PK,FK)
-----------------------------------
1 2 // 1 knows 2
2 1 // 2 knows 1
1 3 // 1 knows 3
2 3 // 2 knows 3
2 4 // 2 knows 4
2 5 // 2 knows 5 // updated
3 5 // 3 knows 5 // updated
1 100
1 200
1 300
100 400
200 400
300 400
Both composite primary keys are also foreign keys from PLAYER table.
I asked and got answered from such nice people for "people know each other".
SQL view for acquaintance from table.
And I have a view like this.
ACQUAINTANCE (VIEW)
-----------------------------------
PLAYER_ID(PK,FK) FRIEND_ID(PK,FK)
-----------------------------------
1 2