How to create a restriction(index) in mongodb?
There is a need, which is I want to make a restriction. A can define B which means the same A cannot have different value B, but the different A can have the same B value.
which can be list as fellows:
field A | field B
1 2
1 3(not allowed )
2 3(allowed)
4 2(allowed)
mongodb
asked Nov 16 '18 at 3:24
Alex XuAlex Xu
94
add a comment |
There is a need, which is I want to make a restriction. A can define B which means the same A cannot have different value B, but the different A can have the same B value.
which can be list as fellows:
field A | field B
1 2
1 3(not allowed )
2 3(allowed)
4 2(allowed)
mongodb
asked Nov 16 '18 at 3:24
Alex XuAlex Xu
94
add a comment |
There is a need, which is I want to make a restriction. A can define B which means the same A cannot have different value B, but the different A can have the same B value.
which can be list as fellows:
field A | field B
1 2
1 3(not allowed )
2 3(allowed)
4 2(allowed)
mongodb
asked Nov 16 '18 at 3:24
Alex XuAlex Xu
94
There is a need, which is I want to make a restriction. A can define B which means the same A cannot have different value B, but the different A can have the same B value.
which can be list as fellows:
field A | field B
1 2
1 3(not allowed )
2 3(allowed)
4 2(allowed)
mongodb
mongodb
asked Nov 16 '18 at 3:24
Alex XuAlex Xu
94
asked Nov 16 '18 at 3:24
Alex XuAlex Xu
94
asked Nov 16 '18 at 3:24
Alex XuAlex Xu
94
asked Nov 16 '18 at 3:24
Alex XuAlex Xu
94
asked Nov 16 '18 at 3:24
Alex XuAlex Xu
94
94
add a comment |
add a comment |
1 Answer
1
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From the docs:
Unique Compound Index
You can also enforce a unique constraint on compound indexes. If you use the unique constraint on a compound index, then MongoDB will enforce uniqueness on the combination of the index key values.
So you can do something like:
db.collection.createIndex( { a: 1, b: 1 }, { unique: true } )
answered Nov 16 '18 at 4:04
BajalBajal
2,39911218
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
From the docs:
Unique Compound Index
You can also enforce a unique constraint on compound indexes. If you use the unique constraint on a compound index, then MongoDB will enforce uniqueness on the combination of the index key values.
So you can do something like:
db.collection.createIndex( { a: 1, b: 1 }, { unique: true } )
answered Nov 16 '18 at 4:04
BajalBajal
2,39911218
add a comment |
From the docs:
Unique Compound Index
You can also enforce a unique constraint on compound indexes. If you use the unique constraint on a compound index, then MongoDB will enforce uniqueness on the combination of the index key values.
So you can do something like:
db.collection.createIndex( { a: 1, b: 1 }, { unique: true } )
answered Nov 16 '18 at 4:04
BajalBajal
2,39911218
add a comment |
From the docs:
Unique Compound Index
You can also enforce a unique constraint on compound indexes. If you use the unique constraint on a compound index, then MongoDB will enforce uniqueness on the combination of the index key values.
So you can do something like:
db.collection.createIndex( { a: 1, b: 1 }, { unique: true } )
answered Nov 16 '18 at 4:04
BajalBajal
2,39911218
From the docs:
Unique Compound Index
You can also enforce a unique constraint on compound indexes. If you use the unique constraint on a compound index, then MongoDB will enforce uniqueness on the combination of the index key values.
So you can do something like:
db.collection.createIndex( { a: 1, b: 1 }, { unique: true } )
answered Nov 16 '18 at 4:04
BajalBajal
2,39911218
answered Nov 16 '18 at 4:04
BajalBajal
2,39911218
answered Nov 16 '18 at 4:04
BajalBajal
2,39911218
answered Nov 16 '18 at 4:04
BajalBajal
2,39911218
2,39911218
add a comment |
add a comment |
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