internal DbGroupByExpression(
TypeUsage collectionOfRowResultType,
DbGroupExpressionBinding input,
DbExpressionList groupKeys,
ReadOnlyCollection <DbAggregate> aggregates)
: base(DbExpressionKind.GroupBy, collectionOfRowResultType, true)
{
this._input = input;
this._keys = groupKeys;
this._aggregates = aggregates;
}
internal DbGroupByExpression(
TypeUsage collectionOfRowResultType,
DbGroupExpressionBinding input,
DbExpressionList groupKeys,
ReadOnlyCollection <DbAggregate> aggregates)
: base(DbExpressionKind.GroupBy, collectionOfRowResultType)
{
DebugCheck.NotNull(input);
DebugCheck.NotNull(groupKeys);
DebugCheck.NotNull(aggregates);
Debug.Assert(groupKeys.Count > 0 || aggregates.Count > 0, "At least one key or aggregate is required");
_input = input;
_keys = groupKeys;
_aggregates = aggregates;
}
protected virtual DbGroupExpressionBinding VisitGroupExpressionBinding(DbGroupExpressionBinding binding)
{
var result = binding;
if (binding != null)
{
var newInput = VisitExpression(binding.Expression);
if (!ReferenceEquals(binding.Expression, newInput))
{
result = CqtBuilder.GroupBindAs(newInput, binding.VariableName, binding.GroupVariableName);
RebindVariable(binding.Variable, result.Variable);
RebindVariable(binding.GroupVariable, result.GroupVariable);
}
}
return(result);
}
/// <summary>
/// Convenience method for post-processing after a DbGroupExpressionBinding has been visited.
/// </summary>
/// <param name="binding"> The previously visited DbGroupExpressionBinding. </param>
protected virtual void VisitGroupExpressionBindingPost(DbGroupExpressionBinding binding)
{
}
/// <summary>
/// Convenience method to visit the specified <see cref="DbGroupExpressionBinding" />.
/// </summary>
/// <param name="binding"> The DbGroupExpressionBinding to visit. </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="binding" />
/// is null
/// </exception>
protected virtual void VisitGroupExpressionBindingPre(DbGroupExpressionBinding binding)
{
Check.NotNull(binding, "binding");
VisitExpression(binding.Expression);
}
/// <summary>
/// Convenience method for post-processing after a DbGroupExpressionBinding has been visited.
/// </summary>
/// <param name="binding"> The previously visited DbGroupExpressionBinding. </param>
protected virtual void VisitGroupExpressionBindingPost(DbGroupExpressionBinding binding)
{
}
/// <summary>
/// Convenience method to visit the specified <see cref="DbGroupExpressionBinding" />.
/// </summary>
/// <param name="binding"> The DbGroupExpressionBinding to visit. </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="binding" />
/// is null
/// </exception>
protected virtual void VisitGroupExpressionBindingPre(DbGroupExpressionBinding binding)
{
Check.NotNull(binding, "binding");
VisitExpression(binding.Expression);
}
// Utility translator method for lambda expressions that are part of group by. Given a lambda expression and its translated
// inputs, translates the lambda expression, assuming the input needs to be used as a grouping input
private DbExpression TranslateLambda(LambdaExpression lambda, DbExpression input, out DbGroupExpressionBinding binding)
{
input = NormalizeSetSource(input);
// create binding context for this lambda expression
var alias = _aliasGenerator.Next();
binding = input.GroupBindAs(alias, string.Format(CultureInfo.InvariantCulture, "Group{0}", alias));
return TranslateLambda(lambda, binding.Variable);
}
protected virtual void VisitGroupExpressionBindingPre(DbGroupExpressionBinding binding)
{
if (binding == null) throw new ArgumentException("binding");
VisitExpression(binding.Expression);
}
/// <summary>
/// Convenience method to visit the specified <see cref="DbGroupExpressionBinding"/>.
/// </summary>
/// <param name="binding">The DbGroupExpressionBinding to visit.</param>
/// <exception cref="ArgumentNullException"><paramref name="binding"/> is null</exception>
protected virtual void VisitGroupExpressionBindingPre(DbGroupExpressionBinding binding)
{
ADP1.CheckArgumentNull(binding, "binding");
VisitExpression(binding.Expression);
}
/// <summary>
/// Convenience method to visit the specified <see cref="T:System.Data.Entity.Core.Common.CommandTrees.DbGroupExpressionBinding" />.
/// </summary>
/// <param name="binding"> The DbGroupExpressionBinding to visit. </param>
/// <exception cref="T:System.ArgumentNullException">
/// <paramref name="binding" />
/// is null
/// </exception>
protected virtual void VisitGroupExpressionBindingPre(DbGroupExpressionBinding binding)
{
Check.NotNull <DbGroupExpressionBinding>(binding, nameof(binding));
this.VisitExpression(binding.Expression);
}
