Update only some attributes of an entity
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I'm new to Core Data and I would like to update only some attributes of an entity that may or may not yet exist in the store.
What I'm currently doing is inserting a new entity with only a few fields set, but afterwards I find that the other attributes have been reset to nil on entities for which those attributes have already been set.
I am using a merge policy of NSMergeByPropertyObjectTrumpMergePolicy which I believe would overwrite only the attributes I have set on my latest update.
I would like to avoid a complicated approach of first obtaining the entity, and then doing a field-by-field reset using old values.
core-data
asked Nov 22 at 1:14
andrewz
1,74532544
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up vote
0
down vote
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I'm new to Core Data and I would like to update only some attributes of an entity that may or may not yet exist in the store.
What I'm currently doing is inserting a new entity with only a few fields set, but afterwards I find that the other attributes have been reset to nil on entities for which those attributes have already been set.
I am using a merge policy of NSMergeByPropertyObjectTrumpMergePolicy which I believe would overwrite only the attributes I have set on my latest update.
I would like to avoid a complicated approach of first obtaining the entity, and then doing a field-by-field reset using old values.
core-data
asked Nov 22 at 1:14
andrewz
1,74532544
If you are always inserting a new entity, you are creating multiple entities. How do you make sure that you are updating the existing entity? Can you show your code?
– Mike Taverne
Nov 24 at 0:45
I have a constraint on an attribute in the entity that ensures uniqueness based on that attribute,
– andrewz
Nov 24 at 1:22
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I'm new to Core Data and I would like to update only some attributes of an entity that may or may not yet exist in the store.
What I'm currently doing is inserting a new entity with only a few fields set, but afterwards I find that the other attributes have been reset to nil on entities for which those attributes have already been set.
I am using a merge policy of NSMergeByPropertyObjectTrumpMergePolicy which I believe would overwrite only the attributes I have set on my latest update.
I would like to avoid a complicated approach of first obtaining the entity, and then doing a field-by-field reset using old values.
core-data
asked Nov 22 at 1:14
andrewz
1,74532544
I'm new to Core Data and I would like to update only some attributes of an entity that may or may not yet exist in the store.
What I'm currently doing is inserting a new entity with only a few fields set, but afterwards I find that the other attributes have been reset to nil on entities for which those attributes have already been set.
I am using a merge policy of NSMergeByPropertyObjectTrumpMergePolicy which I believe would overwrite only the attributes I have set on my latest update.
I would like to avoid a complicated approach of first obtaining the entity, and then doing a field-by-field reset using old values.
core-data
core-data
asked Nov 22 at 1:14
andrewz
1,74532544
asked Nov 22 at 1:14
andrewz
1,74532544
edited Nov 22 at 1:23
asked Nov 22 at 1:14
andrewz
1,74532544
asked Nov 22 at 1:14
andrewz
1,74532544
asked Nov 22 at 1:14
andrewz
1,74532544
1,74532544
If you are always inserting a new entity, you are creating multiple entities. How do you make sure that you are updating the existing entity? Can you show your code?
– Mike Taverne
Nov 24 at 0:45
I have a constraint on an attribute in the entity that ensures uniqueness based on that attribute,
– andrewz
Nov 24 at 1:22
add a comment |
If you are always inserting a new entity, you are creating multiple entities. How do you make sure that you are updating the existing entity? Can you show your code?
– Mike Taverne
Nov 24 at 0:45
I have a constraint on an attribute in the entity that ensures uniqueness based on that attribute,
– andrewz
Nov 24 at 1:22
If you are always inserting a new entity, you are creating multiple entities. How do you make sure that you are updating the existing entity? Can you show your code?
– Mike Taverne
Nov 24 at 0:45
If you are always inserting a new entity, you are creating multiple entities. How do you make sure that you are updating the existing entity? Can you show your code?
– Mike Taverne
Nov 24 at 0:45
I have a constraint on an attribute in the entity that ensures uniqueness based on that attribute,
– andrewz
Nov 24 at 1:22
I have a constraint on an attribute in the entity that ensures uniqueness based on that attribute,
– andrewz
Nov 24 at 1:22
add a comment |
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If you are always inserting a new entity, you are creating multiple entities. How do you make sure that you are updating the existing entity? Can you show your code?
– Mike Taverne
Nov 24 at 0:45
I have a constraint on an attribute in the entity that ensures uniqueness based on that attribute,
– andrewz
Nov 24 at 1:22