private IEnumerable<Expression> CreateIncludeRelatedValuesStrategyFactories(
IQuerySource querySource,
IEnumerable<INavigation> navigationPath)
{
var selectExpression
= _queryCompilationContext.FindSelectExpression(querySource);
var targetTableExpression
= selectExpression.FindTableForQuerySource(querySource);
var readerIndex = 0;
var canProduceInnerJoin = true;
foreach (var navigation in navigationPath)
{
var targetEntityType = navigation.GetTargetType();
var targetTableName = _queryCompilationContext.GetTableName(targetEntityType);
var targetTableAlias = targetTableName[0].ToString().ToLower();
if (!navigation.IsCollection())
{
var joinedTableExpression
= new TableExpression(
targetTableName,
_queryCompilationContext.GetSchema(targetEntityType),
targetTableAlias,
querySource);
var valueBufferOffset = selectExpression.Projection.Count;
canProduceInnerJoin
= canProduceInnerJoin
&& (navigation.ForeignKey.IsRequired
&& navigation.PointsToPrincipal());
var joinExpression
= canProduceInnerJoin
? selectExpression
.AddInnerJoin(joinedTableExpression)
: selectExpression
.AddOuterJoin(joinedTableExpression);
var materializer
= new MaterializerFactory(
_queryCompilationContext.EntityMaterializerSource)
.CreateMaterializer(
targetEntityType,
selectExpression,
projectionAdder:
(p, se) => se.AddToProjection(
new AliasExpression(
new ColumnExpression(
_queryCompilationContext.GetColumnName(p),
p,
joinedTableExpression))) - valueBufferOffset,
querySource: null);
joinExpression.Predicate
= BuildJoinEqualityExpression(
navigation,
(navigation.PointsToPrincipal()
? targetEntityType
: navigation.EntityType)
.GetPrimaryKey().Properties,
navigation.PointsToPrincipal() ? targetTableExpression : joinExpression,
navigation.PointsToPrincipal() ? joinExpression : targetTableExpression);
targetTableExpression = joinedTableExpression;
yield return
Expression.Lambda(
Expression.Call(
_queryCompilationContext.QueryMethodProvider
.CreateReferenceIncludeRelatedValuesStrategyMethod,
Expression.Convert(
EntityQueryModelVisitor.QueryContextParameter,
typeof(RelationalQueryContext)),
Expression.Constant(valueBufferOffset),
Expression.Constant(readerIndex),
materializer));
}
else
{
var principalTable
= selectExpression.Tables.Last(t => t.QuerySource == querySource);
foreach (var property in navigation.EntityType.GetPrimaryKey().Properties)
{
selectExpression
.AddToOrderBy(
_queryCompilationContext.GetColumnName(property),
property,
principalTable,
OrderingDirection.Asc);
}
var targetSelectExpression = new SelectExpression();
targetTableExpression
= new TableExpression(
targetTableName,
_queryCompilationContext.GetSchema(targetEntityType),
targetTableAlias,
querySource);
targetSelectExpression.AddTable(targetTableExpression);
var materializer
= new MaterializerFactory(
_queryCompilationContext.EntityMaterializerSource)
.CreateMaterializer(
targetEntityType,
targetSelectExpression,
(p, se) => se.AddToProjection(
_queryCompilationContext.GetColumnName(p),
p,
querySource),
querySource: null);
var innerJoinSelectExpression
= selectExpression.Clone(
selectExpression.OrderBy.Select(o => o.Expression).Last(o => o.IsAliasWithColumnExpression())
.TryGetColumnExpression().TableAlias);
innerJoinSelectExpression.IsDistinct = true;
innerJoinSelectExpression.ClearProjection();
foreach (var expression
in innerJoinSelectExpression.OrderBy
.Select(o => o.Expression))
{
innerJoinSelectExpression.AddToProjection(expression);
}
innerJoinSelectExpression.ClearOrderBy();
var primaryKeyProperties = navigation.EntityType.GetPrimaryKey().Properties;
var innerJoinExpression
= targetSelectExpression.AddInnerJoin(innerJoinSelectExpression);
targetSelectExpression.UpdateOrderByColumnBinding(selectExpression.OrderBy, innerJoinExpression);
innerJoinExpression.Predicate
= BuildJoinEqualityExpression(
navigation,
primaryKeyProperties,
targetTableExpression,
innerJoinExpression);
selectExpression = targetSelectExpression;
readerIndex++;
yield return
Expression.Lambda(
Expression.Call(
_queryCompilationContext.QueryMethodProvider
.CreateCollectionIncludeRelatedValuesStrategyMethod,
Expression.Call(
_queryCompilationContext.QueryMethodProvider.QueryMethod,
EntityQueryModelVisitor.QueryContextParameter,
Expression.Constant(
new CommandBuilder(
() => _queryCompilationContext.CreateSqlQueryGenerator(targetSelectExpression),
_queryCompilationContext.ValueBufferFactoryFactory))),
materializer));
}
}
}
