/// <summary>
/// Creates a <see cref="DbOrderByExpression"/> that represents ordering the result set.
/// </summary>
/// <param name="dbSelectQuery">The target <see cref="DbQuery{TQueryExpression}"/>.</param>
/// <param name="expressionSelector">A function used to specify an element in the 'ORDER BY' clause.</param>
/// <param name="orderByExpressionType">Specifies the sort order direction.</param>
/// <returns></returns>
public static DbQuery<DbSelectExpression> OrderBy(this DbQuery<DbSelectExpression> dbSelectQuery, Func<DbExpressionFactory, DbExpression> expressionSelector, DbOrderByExpressionType orderByExpressionType)
{
var dbExpression = (DbExpression)DbExpressionFactory.MakeOrderBy(orderByExpressionType, expressionSelector(DbExpressionFactory));
if (!dbSelectQuery.QueryExpression.OrderByExpression.IsNull())
dbExpression = DbExpressionFactory.List(new[] { dbSelectQuery.QueryExpression.FromExpression, dbExpression });
dbSelectQuery.QueryExpression.OrderByExpression = dbExpression;
return dbSelectQuery;
}
/// <summary>
/// Creates a new <see cref="DbOrderByExpression"/> that represents ordering the result set.
/// </summary>
/// <param name="orderByExpressionType">The <see cref="DbOrderByExpressionType"/> that specifies the ordering direction.</param>
/// <param name="expression">The <see cref="DbExpression"/> representing an element in the 'ORDER BY' clause.</param>
/// <returns>A <see cref="DbOrderByExpression"/> instance.</returns>
public DbOrderByExpression MakeOrderBy(DbOrderByExpressionType orderByExpressionType, DbExpression expression)
{
var dbOrderByExpression = new DbOrderByExpression
{ OrderByExpressionType = orderByExpressionType, Expression = expression };
return dbOrderByExpression;
}
/// <summary>
/// Creates a <see cref="DbOrderByExpression"/> that represents ordering the result set.
/// </summary>
/// <param name="dbSelectQuery">The target <see cref="DbQuery{TQueryExpression}"/>.</param>
/// <param name="expressionSelector">A function used to specify an element in the 'ORDER BY' clause.</param>
/// <param name="orderByExpressionType">Specifies the sort order direction.</param>
/// <returns></returns>
public static DbQuery <DbSelectExpression> OrderBy(this DbQuery <DbSelectExpression> dbSelectQuery, Func <DbExpressionFactory, DbExpression> expressionSelector, DbOrderByExpressionType orderByExpressionType)
{
var dbExpression = (DbExpression)DbExpressionFactory.MakeOrderBy(orderByExpressionType, expressionSelector(DbExpressionFactory));
if (!dbSelectQuery.QueryExpression.OrderByExpression.IsNull())
{
dbExpression = DbExpressionFactory.List(new[] { dbSelectQuery.QueryExpression.OrderByExpression, dbExpression });
}
dbSelectQuery.QueryExpression.OrderByExpression = dbExpression;
return(dbSelectQuery);
}
