Searching on String Fields

Marten supports a subset of the common sub/string searches:

public void string_fields(IDocumentSession session)
{
    session.Query<Target>().Where(x => x.String.StartsWith("A"));
    session.Query<Target>().Where(x => x.String.EndsWith("Suffix"));

    session.Query<Target>().Where(x => x.String.Contains("something"));
    session.Query<Target>().Where(x => x.String.Equals("The same thing"));
}

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Marten also supports case insensitive substring searches:

public void case_insensitive_string_fields(IDocumentSession session)
{
    session.Query<Target>().Where(x => x.String.StartsWith("A", StringComparison.OrdinalIgnoreCase));
    session.Query<Target>().Where(x => x.String.EndsWith("SuFfiX", StringComparison.OrdinalIgnoreCase));

    // using Marten.Util
    session.Query<Target>().Where(x => x.String.Contains("soMeThiNg", StringComparison.OrdinalIgnoreCase));

    session.Query<Target>().Where(x => x.String.Equals("ThE SaMe ThInG", StringComparison.OrdinalIgnoreCase));

}

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A shorthand for case-insensitive string matching is provided through EqualsIgnoreCase (string extension method in JasperFx.Core):

(await query.Query<User>().SingleAsync(x => x.UserName.EqualsIgnoreCase("abc"))).Id.ShouldBe(user1.Id);
(await query.Query<User>().SingleAsync(x => x.UserName.EqualsIgnoreCase("aBc"))).Id.ShouldBe(user1.Id);

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Marten translates EqualsIgnoreCase to a PostgreSQL case-insensitive pattern-match (~~*, equivalent to ILIKE) rather than a .NET culture-aware comparison.