public static IQueryable <QEntity> LeftJoin <QEntity, QKey, JEntity, JKey>( //LeftJoin == + .DefaultIfEmpty()
this IQueryable <QEntity> query,
LinqToDB.ITable <JEntity> table,
Expression <Func <QEntity, QKey> > queryKey,
Expression <Func <JEntity, JKey> > joinKey,
Expression <Func <QEntity, JEntity> > resultSelectorExpression
)
{
var joinPropertyInfo = ((PropertyInfo)((MemberExpression)joinKey.Body).Member);
var queryParameter = Expression.Parameter(typeof(QEntity), "query");
var joinCollectionParameter = Expression.Parameter(typeof(IQueryable <JEntity>), "joinCollection"); //ex. (l, r) => ...
//join => query.ForeignKeyId == (queryType)join.Id
var wherePredicate = CreateWherePredicate <QEntity, QKey, JEntity>(queryParameter, queryKey, joinPropertyInfo.Name);
var whereCall = CreateWhereCall <JEntity>(joinCollectionParameter, wherePredicate);
var defaultIfEmptyMethodInfo = GetDefaultIfEmpty();
var genericDefaultIfEmptyMethodInfo = defaultIfEmptyMethodInfo.MakeGenericMethod(typeof(JEntity));
var defaultIfEmptyCall = Expression.Call(genericDefaultIfEmptyMethodInfo, whereCall);
//query => Queryable.Where(joinCollection, join => query.ForeignKeyId == (queryType)join.Id)
var collectionSelectorExpression = CreateCollectionSelectorExpression <QEntity, JEntity>(queryParameter, defaultIfEmptyCall);
//(queryCollection, joinCollection) =>
// Queryable.SelectMany(queryCollection, query =>
// Queryable.Where(joinCollection, join => query.ForeignKeyId == (queryType)join.Id),
// (i, j) => i);
var expression = CreateExpression(joinCollectionParameter, collectionSelectorExpression, Bind(resultSelectorExpression));
return(expression.Compile()(query, table));
}
public static IQueryable <QEntity> Join <QEntity, QKey, JEntity, JKey>( //LeftJoin == + .DefaultIfEmpty()
this IQueryable <QEntity> query,
LinqToDB.ITable <JEntity> table,
Expression <Func <QEntity, QKey> > queryKey,
Expression <Func <JEntity, JKey> > joinKey,
Expression <Func <QEntity, JEntity> > resultSelectorExpression
)
{
var joinPropertyInfo = ((PropertyInfo)((MemberExpression)joinKey.Body).Member);
var queryParameter = Expression.Parameter(typeof(QEntity), "query");
var joinCollectionParameter = Expression.Parameter(typeof(IQueryable <JEntity>), "joinCollection"); //ex. (l, r) => ...
//join => query.ForeignKeyId == (queryType)join.Id
var wherePredicate = CreateWherePredicate <QEntity, QKey, JEntity>(queryParameter, queryKey, joinPropertyInfo.Name);
var whereCall = CreateWhereCall <JEntity>(joinCollectionParameter, wherePredicate);
//query => Queryable.Where(joinCollection, join => query.ForeignKeyId == (queryType)join.Id)
var collectionSelectorExpression = CreateCollectionSelectorExpression <QEntity, JEntity>(queryParameter, whereCall);
//var resultBinding = Bind(resultSelectorExpression);
//Bind<User, Street>((u, s) => new User { Address = new Address { Street = s }});
//resultSelectorExpression.ToString().Dump();
//resultBinding.ToString().Dump();
//(queryCollection, joinCollection) =>
// Queryable.SelectMany(queryCollection, query =>
// Queryable.Where(joinCollection, join => query.ForeignKeyId == (queryType)join.Id),
// (i, j) => i);
var expression = CreateExpression(joinCollectionParameter, collectionSelectorExpression, Bind(resultSelectorExpression));
//expression.Dump(1);
return(expression.Compile()(query, table));
}
