Normaly a pair has 2 players, but if there is an odd number of players ate the club, one 'pair' has 3 players.

Table, members:

pair, player_id

1 1
1 2
2 3
2 4
3 5
3 6
4 7
4 8
5 9
5 10
6 11
6 12
6 13

table players:

id name

1 Smith
2 Brown
3 Johnson
4 Wild
5 Hammer
6 Bolt
7 Pink
8 Bush
9 Novak
10 King
11 Holmes
12 Watson
13 Gold

Required result of select is:

Pair, Names
1, Smith - Brown
2, Johnson - Wild
3, Hammer - Bolt
4, Pink - Bush
5, Novak - King
6, Holmes - Watson - Gold

Normaly a pair has 2 players, but if there is an odd number of players at the club, one 'pair' has 3 players.

Table, members:

pair, player_id

1 1
1 2
2 3
2 4
3 5
3 6
4 7
4 8
5 9
5 10
6 11
6 12
6 13

table players:

id name

1 Smith
2 Brown
3 Johnson
4 Wild
5 Hammer
6 Bolt
7 Pink
8 Bush
9 Novak
10 King
11 Holmes
12 Watson
13 Gold

Required result of select is:

Pair, Names
1, Smith - Brown
2, Johnson - Wild
3, Hammer - Bolt
4, Pink - Bush
5, Novak - King
6, Holmes - Watson - Gold

Normaly pair have 2 players, but if in club is any odd number of players, one pair have 3 players.

How define select, if have table members with too columns

pair, player_id

1 1
1 2
2 3
2 4
3 5
3 6
4 7
4 8
5 9
5 10
6 11
6 12
6 13

table players with id , name

1 Smith
2 Brown
3 Johnson
4 Wild
5 Hammer
6 Bolt
7 Pink
8 Bush
9 Novak
10 King
11 Holmes
12 Watson
13 Gold

An result of select is

1 Smith - Brown
2 Johnson - Wild
3 Hammer - Bolt
4 Pink - Bush
5 Novak - King
6 Holmes - Watson - Gold

Normaly a pair has 2 players, but if there is an odd number of players ate the club, one 'pair' has 3 players.

Table, members:

pair, player_id

1 1
1 2
2 3
2 4
3 5
3 6
4 7
4 8
5 9
5 10
6 11
6 12
6 13

table players:

id name

1 Smith
2 Brown
3 Johnson
4 Wild
5 Hammer
6 Bolt
7 Pink
8 Bush
9 Novak
10 King
11 Holmes
12 Watson
13 Gold

Required result of select is:

Pair, Names
1, Smith - Brown
2, Johnson - Wild
3, Hammer - Bolt
4, Pink - Bush
5, Novak - King
6, Holmes - Watson - Gold