CODEWITHSUNDEEP
sqliteentity-framework-core
Henrik Ilgen
Henrik Ilgen

Reputation: 1967

Compare strings ignoring case

I am trying to find entities (Tags) in the database via their Name property, where it is important to ignore the case (When database is searched and the Database contains a Tag with the name Database, that one should be returned). Right now, my code looks like this:

public IEnumerable<db.Tag> FindByNames(IEnumerable<string> tagNames)
{
    return this.DatabaseContext.Tags
        .Where(tag => tagNames.Contains(tag.Name));
}

Obviously, this one is case sensitive. I have tried to provide StringComparer.OrdinalIgnoreCase as comparer to the Contains method, but got a warning during execution that the expression could not be translated and would be executed in code rather than in the database (I don't remember the exact message, I will edit as soon as I am back on my development machine). I can live with that if I have to, but it would be nice to know how to let the database do the work in this case. Is it possible?

Upvotes: 2

Views: 961

Answers (1)

natemcmaster
natemcmaster

Reputation: 26773

No change should be necessary. SQLite's "LIKE" is already case-insensitive.

The default behavior of the LIKE operator is to ignore case for ASCII characters.

(cref https://www.sqlite.org/pragma.html#pragma_case_sensitive_like and Case sensitive and insensitive like in SQLite)

Of course, you can always use .FromSql() to get the exact query you want. Example:

context.Tags.FromSql("SELECT * FROM tags WHERE name LIKE '%{0}%'", tagName)

Upvotes: 1

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