问题
Does OData specify whether filter conditions on string fields are to be evaluated case-sensitively or case-insensitively?
Example: (from the docs)
/Suppliers?$filter=Address/City eq 'Redmond'
Is this expected to be case-sensitive or not?
If I want to offer both options, how can this be expressed? There is a tolower() function that can be used like:
/Suppliers?$filter=tolower(Address/City) eq 'redmond'
or
/Suppliers?$filter=tolower(Address/City) eq tolower('Redmond')
Isn't there a more concise way to express case-insensitive matching?
回答1:
The "eq" operator is supposed to be case sensitive. Usage of tolower (or toupper) is the currently recommended way of doing this.
回答2:
It is now possible to do case insensitive compare by setting EnableCaseInsensitive = true on the ODataUriResolver. I used this with Microsoft.AspNetCore.OData 7.1.0.
var oDataUriParser = new ODataUriParser(model, uri)
{
Resolver = new ODataUriResolver { EnableCaseInsensitive = true}
};
Source: https://github.com/OData/WebApi/issues/812
回答3:
I would expect this is depended on your database collation setting, as the odata service is just performing a query. If Vitek's answer is correct, then odata is doing some post query filtering on the result set, and that should be strange, right?
回答4:
It doesn't depend on database. Even if you perform query against database in case in-sensitive way then OData will do his own additional filtering and filter your data out.
来源：https://stackoverflow.com/questions/13495905/odata-query-filter-conditions-and-case-sensitivity