Removing aliases from a SQL select statement

private string RemoveAliases(string sqlSelectString)

{

    sqlSelectString = sqlSelectString.ToLower();

    

    const string ALIAS_INDICATOR = " as ";

    int aliasIndex;

    int commaIndex;

    string modifiedSqlString;

    do

    {

        modifiedSqlString = sqlSelectString;

        aliasIndex = sqlSelectString.IndexOf(ALIAS_INDICATOR, System.StringComparison.Ordinal);

        if (aliasIndex != -1)

        {

            string columnTextExpressionAlias = sqlSelectString.Substring(aliasIndex);

            commaIndex = columnTextExpressionAlias.IndexOf(",", System.StringComparison.Ordinal);

            if (commaIndex != -1)

            {

                sqlSelectString = sqlSelectString.Remove(aliasIndex, commaIndex);

            }

            else

            {

                sqlSelectString = sqlSelectString.Remove(aliasIndex, columnTextExpressionAlias.Length);

            }

        }

    }

    while (sqlSelectString != modifiedSqlString);

    return sqlSelectString;

}