String Comparison exception within Entity Framework FirstOrDefault
I'm querying a table using Entity Framework. The first bit of code was what I wrote, the second bit was what ReSharper suggested I refactor it too. The first one gracefully returns null as it should if the key doesn't exist, but the second throws an exception.
This was attempted with 0-1 records in the table (all of the columns are marked as NOT NULL)
Code that works:
context.brandlink.FirstOrDefault(x => x.ManufacturerKey.ToLower() == manufacturerKey.ToLower());
and code that doesn't work:
context.brandlink.FirstOrDefault(x => String.Equals(x.ManufacturerKey, manufacturerKey, StringComparison.InvariantCultureIgnoreCase));
Exception thrown:
Incorrect number of arguments supplied for call to method 'Boolean
Equals(System.String, System.String, System.StringComparison)'
So my question is: what is the difference between the two expressions?
c# entity-framework string-comparison
edited Mar 11 '16 at 21:39
marc_s
583k13011241270
asked Mar 11 '16 at 21:14
NickNick
3422418
add a comment |
I'm querying a table using Entity Framework. The first bit of code was what I wrote, the second bit was what ReSharper suggested I refactor it too. The first one gracefully returns null as it should if the key doesn't exist, but the second throws an exception.
This was attempted with 0-1 records in the table (all of the columns are marked as NOT NULL)
Code that works:
context.brandlink.FirstOrDefault(x => x.ManufacturerKey.ToLower() == manufacturerKey.ToLower());
and code that doesn't work:
context.brandlink.FirstOrDefault(x => String.Equals(x.ManufacturerKey, manufacturerKey, StringComparison.InvariantCultureIgnoreCase));
Exception thrown:
Incorrect number of arguments supplied for call to method 'Boolean
Equals(System.String, System.String, System.StringComparison)'
So my question is: what is the difference between the two expressions?
c# entity-framework string-comparison
edited Mar 11 '16 at 21:39
marc_s
583k13011241270
asked Mar 11 '16 at 21:14
NickNick
3422418
add a comment |
I'm querying a table using Entity Framework. The first bit of code was what I wrote, the second bit was what ReSharper suggested I refactor it too. The first one gracefully returns null as it should if the key doesn't exist, but the second throws an exception.
This was attempted with 0-1 records in the table (all of the columns are marked as NOT NULL)
Code that works:
context.brandlink.FirstOrDefault(x => x.ManufacturerKey.ToLower() == manufacturerKey.ToLower());
and code that doesn't work:
context.brandlink.FirstOrDefault(x => String.Equals(x.ManufacturerKey, manufacturerKey, StringComparison.InvariantCultureIgnoreCase));
Exception thrown:
Incorrect number of arguments supplied for call to method 'Boolean
Equals(System.String, System.String, System.StringComparison)'
So my question is: what is the difference between the two expressions?
c# entity-framework string-comparison
edited Mar 11 '16 at 21:39
marc_s
583k13011241270
asked Mar 11 '16 at 21:14
NickNick
3422418
I'm querying a table using Entity Framework. The first bit of code was what I wrote, the second bit was what ReSharper suggested I refactor it too. The first one gracefully returns null as it should if the key doesn't exist, but the second throws an exception.
This was attempted with 0-1 records in the table (all of the columns are marked as NOT NULL)
Code that works:
context.brandlink.FirstOrDefault(x => x.ManufacturerKey.ToLower() == manufacturerKey.ToLower());
and code that doesn't work:
context.brandlink.FirstOrDefault(x => String.Equals(x.ManufacturerKey, manufacturerKey, StringComparison.InvariantCultureIgnoreCase));
Exception thrown:
Incorrect number of arguments supplied for call to method 'Boolean
Equals(System.String, System.String, System.StringComparison)'
So my question is: what is the difference between the two expressions?
c# entity-framework string-comparison
c# entity-framework string-comparison
edited Mar 11 '16 at 21:39
marc_s
583k13011241270
asked Mar 11 '16 at 21:14
NickNick
3422418
edited Mar 11 '16 at 21:39
marc_s
583k13011241270
asked Mar 11 '16 at 21:14
NickNick
3422418
edited Mar 11 '16 at 21:39
marc_s
583k13011241270
edited Mar 11 '16 at 21:39
marc_s
583k13011241270
edited Mar 11 '16 at 21:39
marc_s
583k13011241270
583k13011241270
asked Mar 11 '16 at 21:14
NickNick
3422418
asked Mar 11 '16 at 21:14
NickNick
3422418
asked Mar 11 '16 at 21:14
NickNick
3422418
3422418
add a comment |
add a comment |
1 Answer
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So my question is: what is the difference between the two expressions?
The diffence is that the later is using the CLR String.Equals Method (String, String, StringComparison) which is not supported by EF according to CLR Method to Canonical Function Mapping while all the methods used in the former (string.ToLower and string equality operator) are supported.
In general you cannot control the sting comparisons for EF queries from code because they are controlled by the database.
answered Mar 11 '16 at 21:39
Ivan StoevIvan Stoev
108k786140
add a comment |
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1 Answer
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active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
So my question is: what is the difference between the two expressions?
The diffence is that the later is using the CLR String.Equals Method (String, String, StringComparison) which is not supported by EF according to CLR Method to Canonical Function Mapping while all the methods used in the former (string.ToLower and string equality operator) are supported.
In general you cannot control the sting comparisons for EF queries from code because they are controlled by the database.
answered Mar 11 '16 at 21:39
Ivan StoevIvan Stoev
108k786140
add a comment |
So my question is: what is the difference between the two expressions?
The diffence is that the later is using the CLR String.Equals Method (String, String, StringComparison) which is not supported by EF according to CLR Method to Canonical Function Mapping while all the methods used in the former (string.ToLower and string equality operator) are supported.
In general you cannot control the sting comparisons for EF queries from code because they are controlled by the database.
answered Mar 11 '16 at 21:39
Ivan StoevIvan Stoev
108k786140
add a comment |
So my question is: what is the difference between the two expressions?
The diffence is that the later is using the CLR String.Equals Method (String, String, StringComparison) which is not supported by EF according to CLR Method to Canonical Function Mapping while all the methods used in the former (string.ToLower and string equality operator) are supported.
In general you cannot control the sting comparisons for EF queries from code because they are controlled by the database.
answered Mar 11 '16 at 21:39
Ivan StoevIvan Stoev
108k786140
So my question is: what is the difference between the two expressions?
The diffence is that the later is using the CLR String.Equals Method (String, String, StringComparison) which is not supported by EF according to CLR Method to Canonical Function Mapping while all the methods used in the former (string.ToLower and string equality operator) are supported.
In general you cannot control the sting comparisons for EF queries from code because they are controlled by the database.
answered Mar 11 '16 at 21:39
Ivan StoevIvan Stoev
108k786140
answered Mar 11 '16 at 21:39
Ivan StoevIvan Stoev
108k786140
answered Mar 11 '16 at 21:39
Ivan StoevIvan Stoev
108k786140
answered Mar 11 '16 at 21:39
Ivan StoevIvan Stoev
108k786140
108k786140
add a comment |
add a comment |
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