Nhibernate QueryOver collation without hard coded column name

Question

So I have the following sql

SELECT * FROM table Where Name COLLATE LATIN1_GENERAL_CI_AI LIKE \'myText%\'

which I want to implement using QueryOver

At

Answer 1

I've implemented it this way. Not sure if there is any better way...

I. The like expression, profiting from the existing Like expression

public class LikeCollationExpression : LikeExpression
{
    const string CollationDefinition = " COLLATE {0} ";
    const string Latin_CI_AI = "LATIN1_GENERAL_CI_AI";

    // just a set of constructors
    public LikeCollationExpression(string propertyName, string value, char? escapeChar, bool ignoreCase) : base(propertyName, value, escapeChar, ignoreCase) { }
    public LikeCollationExpression(IProjection projection, string value, MatchMode matchMode) : base(projection, value, matchMode) { }
    public LikeCollationExpression(string propertyName, string value) : base(propertyName, value) { }
    public LikeCollationExpression(string propertyName, string value, MatchMode matchMode) : base(propertyName, value, matchMode) { }
    public LikeCollationExpression(string propertyName, string value, MatchMode matchMode, char? escapeChar, bool ignoreCase) : base(propertyName, value, matchMode, escapeChar, ignoreCase) { }

    // here we call the base and append the COLLATE
    public override SqlString ToSqlString(ICriteria criteria, ICriteriaQuery criteriaQuery, IDictionary<string, IFilter> enabledFilters)
    {
        // base LIKE
        var result = base.ToSqlString(criteria, criteriaQuery, enabledFilters);

        var sqlStringBuilder = new SqlStringBuilder(result);

        // extend it with collate
        sqlStringBuilder.Add(string.Format(CollationDefinition, Latin_CI_AI ));

        return sqlStringBuilder.ToSqlString();
    }
}

II. the custom extension method

public static class QueryOverExt
{
    // here: WhereLikeCiAi() 
    public static IQueryOver<TRoot, TSubType> WhereLikeCiAi<TRoot, TSubType>(
        this IQueryOver<TRoot, TSubType> query
        , Expression<Func<TSubType, object>> expression
        , string value
        , MatchMode matchMode)
    {
        var name = ExpressionProcessor.FindMemberExpression(expression.Body);
        query
            .UnderlyingCriteria
            .Add
            (
                new LikeCollationExpression(name, value, matchMode)
            );
        return query;
    }
}

III. the usage anyhwere in the QueryOverAPI

...
query.WhereLikeCiAi(c => c.Name, "searchedString", MatchMode.Anywhere);