private void GenerateAggregate(SqlGenerator sql, SqlAggregateExpression aggregate)
{
sql.Add(GenerateAggregateName(aggregate.Function));
sql.Add("(");
GenerateFields(sql, aggregate.Arguments);
sql.Add(")");
}
protected override Expression VisitAggregate(SqlAggregateExpression sqlAggregate)
{
if (sqlAggregate.AggregateType == SqlAggregateType.Average && sqlAggregate.Argument.Type.IsIntegerType())
{
return(sqlAggregate.ChangeArgument(Expression.Convert(sqlAggregate.Argument, typeof(double))));
}
return(base.VisitAggregate(sqlAggregate));
}
protected static SqlAggregateExpression UpdateAggregate(SqlAggregateExpression sqlAggregate, Type type, SqlAggregateType aggType, Expression arg, bool isDistinct)
{
if (type != sqlAggregate.Type || aggType != sqlAggregate.AggregateType || arg != sqlAggregate.Argument || isDistinct != sqlAggregate.IsDistinct)
{
return(new SqlAggregateExpression(type, aggType, arg, isDistinct));
}
return(sqlAggregate);
}
protected override Expression VisitSelect(SqlSelectExpression selectExpression)
{
if (selectExpression.Columns.Count == 1 &&
selectExpression.From.NodeType == (ExpressionType)SqlExpressionType.Select &&
selectExpression.Columns[0].Expression.NodeType == (ExpressionType)SqlExpressionType.Aggregate)
{
var from = (SqlSelectExpression)selectExpression.From;
var aggregateExpression = (SqlAggregateExpression)selectExpression.Columns[0].Expression;
if (from.Columns.Count > 1 ||
aggregateExpression.IsDistinct ||
from.Distinct ||
from.Take != null ||
from.Skip != null ||
from.GroupBy != null
/* Don't fold a from with an orderby into the outer select if it has a count or other aggregate */
|| from.OrderBy != null && from.OrderBy.Count > 0 && SqlAggregateChecker.HasAggregates(selectExpression))
{
return(base.VisitSelect(selectExpression));
}
var newColumns = new List <SqlColumnDeclaration>();
if (from.Columns.Count == 1)
{
foreach (var column in from.Columns)
{
if (column.Expression.NodeType != (ExpressionType)SqlExpressionType.Column)
{
return(base.VisitSelect(selectExpression));
}
var newAggregate = new SqlAggregateExpression
(
aggregateExpression.Type,
aggregateExpression.AggregateType,
column.Expression,
aggregateExpression.IsDistinct
);
newColumns.Add(new SqlColumnDeclaration(column.Name, newAggregate));
}
}
else
{
newColumns.Add(selectExpression.Columns[0]);
}
var where = this.Visit(from.Where);
return(from.ChangeWhereAndColumns(where, newColumns.ToReadOnlyList(), from.ForUpdate || selectExpression.ForUpdate));
}
return(base.VisitSelect(selectExpression));
}
protected override Expression VisitAggregate(SqlAggregateExpression sqlAggregate)
{
if (this.currentProjection != null && sqlAggregate.AggregateType == SqlAggregateType.Sum && sqlAggregate.Type.IsNullableType())
{
var defaultValue = this.currentProjection.DefaultValueExpression ?? Expression.Constant(Nullable.GetUnderlyingType(sqlAggregate.Type).GetDefaultValue());
return(new SqlFunctionCallExpression(sqlAggregate.Type, SqlFunction.Coalesce, sqlAggregate, defaultValue));
}
return(sqlAggregate);
}
protected override Expression VisitAggregate(SqlAggregateExpression sqlAggregate)
{
this.Write(GetAggregateName(sqlAggregate.AggregateType));
this.Write("(");
if (sqlAggregate.IsDistinct)
{
this.Write("DISTINCT ");
}
if (sqlAggregate.Argument != null)
{
this.Visit(sqlAggregate.Argument);
}
else if (this.RequiresAsteriskWhenNoArgument(sqlAggregate.AggregateType))
{
this.Write("*");
}
this.Write(")");
return(sqlAggregate);
}
protected override Expression VisitAggregate(SqlAggregateExpression sqlAggregate)
{
this.output.Append(sqlAggregate.ToString());
return(sqlAggregate);
}
protected override Expression VisitAggregate(SqlAggregateExpression aggregate)
{
this.aggregatesFound.Add(aggregate);
return(base.VisitAggregate(aggregate));
}
protected virtual Expression VisitAggregate(SqlAggregateExpression sqlAggregate)
{
var arg = this.Visit(sqlAggregate.Argument);
return(UpdateAggregate(sqlAggregate, sqlAggregate.Type, sqlAggregate.AggregateType, arg, sqlAggregate.IsDistinct));
}
protected override Expression VisitAggregate(SqlAggregateExpression sqlAggregate)
{
this.hasAggregate = true;
return(sqlAggregate);
}
