public static DQueryable <T> SelectMany <T>(this DQueryable <T> query, CollectionElementToken cet)
{
Type elementType = cet.Parent.Type.ElementType();
var collectionSelector = Expression.Lambda(typeof(Func <,>).MakeGenericType(typeof(object), typeof(IEnumerable <>).MakeGenericType(elementType)),
Expression.Call(miDefaultIfEmptyE.MakeGenericMethod(elementType),
cet.Parent.BuildExpression(query.Context)),
query.Context.Parameter);
var elementParameter = cet.CreateParameter();
var properties = query.Context.Replacemens.Values.And(cet.CreateExpression(elementParameter));
var ctor = TupleReflection.TupleChainConstructor(properties);
var resultSelector = Expression.Lambda(Expression.Convert(ctor, typeof(object)), query.Context.Parameter, elementParameter);
var resultQuery = query.Query.Provider.CreateQuery <object>(Expression.Call(null, miSelectMany.MakeGenericMethod(typeof(object), elementType, typeof(object)),
new Expression[] { query.Query.Expression, Expression.Quote(collectionSelector), Expression.Quote(resultSelector) }));
var parameter = Expression.Parameter(typeof(object));
var newReplacements = query.Context.Replacemens.Keys.And(cet).Select((a, i) => new
{
Token = a,
Expression = TupleReflection.TupleChainProperty(Expression.Convert(parameter, ctor.Type), i)
}).ToDictionary(a => a.Token, a => a.Expression);
return(new DQueryable <T>(resultQuery,
new BuildExpressionContext(ctor.Type, parameter, newReplacements)));
}
internal Func <object, PrimaryKey?> GetPrimaryKeyNullableGetter(IColumn column)
{
var access = TupleReflection.TupleChainProperty(Expression.Convert(originObject, tupleType), table.Columns.Values.IndexOf(column));
var primaryKey = WrapPrimaryKey(access);
return(Expression.Lambda <Func <object, PrimaryKey?> >(primaryKey, originObject).Compile());
}
static Expression <Func <object, object> > TupleConstructor(BuildExpressionContext context, HashSet <QueryToken> tokens, out BuildExpressionContext newContext)
{
string str = tokens.Select(t => QueryUtils.CanColumn(t)).NotNull().ToString("\r\n");
if (str == null)
{
throw new ApplicationException(str);
}
List <Expression> expressions = tokens.Select(t => t.BuildExpression(context)).ToList();
Expression ctor = TupleReflection.TupleChainConstructor(expressions);
var pe = Expression.Parameter(typeof(object));
newContext = new BuildExpressionContext(
ctor.Type, pe,
tokens.Select((t, i) => new { Token = t, Expr = TupleReflection.TupleChainProperty(Expression.Convert(pe, ctor.Type), i) }).ToDictionary(t => t.Token, t => t.Expr));
return(Expression.Lambda <Func <object, object> >(
(Expression)Expression.Convert(ctor, typeof(object)), context.Parameter));
}
static LambdaExpression ResultSelectSelectorAndContext(BuildExpressionContext context, HashSet <QueryToken> keyTokens, HashSet <AggregateToken> aggregateTokens, Type keyTupleType, out BuildExpressionContext newContext)
{
Dictionary <QueryToken, Expression> resultExpressions = new Dictionary <QueryToken, Expression>();
ParameterExpression pk = Expression.Parameter(keyTupleType, "key");
resultExpressions.AddRange(keyTokens.Select((kt, i) => KVP.Create(kt,
TupleReflection.TupleChainProperty(pk, i))));
ParameterExpression pe = Expression.Parameter(typeof(IEnumerable <object>), "e");
resultExpressions.AddRange(aggregateTokens.Select(at => KVP.Create((QueryToken)at,
BuildAggregateExpression(pe, at, context))));
var resultConstructor = TupleReflection.TupleChainConstructor(resultExpressions.Values);
ParameterExpression pg = Expression.Parameter(typeof(object), "gr");
newContext = new BuildExpressionContext(resultConstructor.Type, pg,
resultExpressions.Keys.Select((t, i) => KVP.Create(t, TupleReflection.TupleChainProperty(Expression.Convert(pg, resultConstructor.Type), i))).ToDictionary());
return(Expression.Lambda(Expression.Convert(resultConstructor, typeof(object)), pk, pe));
}
public Expression GetTupleProperty(IColumn column)
{
return(TupleReflection.TupleChainProperty(origin, table.Columns.Values.IndexOf(column)));
}