public virtual ISqlQueryGenerator CreateGenerator() => _sqlQueryGeneratorFactory.CreateGenerator(this);
private IEnumerable <Expression> CreateIncludeRelatedValuesStrategyFactories(
IQuerySource querySource,
IEnumerable <INavigation> navigationPath)
{
var selectExpression
= _queryCompilationContext.FindSelectExpression(querySource);
var targetTableExpression
= selectExpression.GetTableForQuerySource(querySource);
var canProduceInnerJoin = true;
var navigationCount = 0;
foreach (var navigation in navigationPath)
{
var queryIndex = _queryIndexes[navigationCount];
navigationCount++;
var targetEntityType = navigation.GetTargetType();
var targetTableName = _relationalAnnotationProvider.For(targetEntityType).TableName;
var targetTableAlias = targetTableName[0].ToString().ToLower();
if (!navigation.IsCollection())
{
var joinedTableExpression
= new TableExpression(
targetTableName,
_relationalAnnotationProvider.For(targetEntityType).Schema,
targetTableAlias,
querySource);
var valueBufferOffset = selectExpression.Projection.Count;
canProduceInnerJoin
= canProduceInnerJoin &&
(navigation.ForeignKey.IsRequired &&
navigation.PointsToPrincipal());
var joinExpression
= canProduceInnerJoin
? selectExpression
.AddInnerJoin(joinedTableExpression)
: selectExpression
.AddOuterJoin(joinedTableExpression);
var oldPredicate = selectExpression.Predicate;
var materializer
= _materializerFactory
.CreateMaterializer(
targetEntityType,
selectExpression,
(p, se) => se.AddToProjection(
new AliasExpression(
new ColumnExpression(
_relationalAnnotationProvider.For(p).ColumnName,
p,
joinedTableExpression))) - valueBufferOffset,
querySource: null);
if (selectExpression.Predicate != oldPredicate)
{
var newJoinExpression = AdjustJoinExpression(selectExpression, joinExpression);
selectExpression.Predicate = oldPredicate;
selectExpression.RemoveTable(joinExpression);
selectExpression.AddTable(newJoinExpression);
joinExpression = newJoinExpression;
}
joinExpression.Predicate
= BuildJoinEqualityExpression(
navigation,
navigation.PointsToPrincipal() ? targetTableExpression : joinExpression,
navigation.PointsToPrincipal() ? joinExpression : targetTableExpression,
querySource);
targetTableExpression = joinedTableExpression;
yield return
(Expression.Lambda(
Expression.Call(
_queryCompilationContext.QueryMethodProvider
.CreateReferenceIncludeRelatedValuesStrategyMethod,
Expression.Convert(
EntityQueryModelVisitor.QueryContextParameter,
typeof(RelationalQueryContext)),
Expression.Constant(valueBufferOffset),
Expression.Constant(queryIndex),
materializer)));
}
else
{
var principalTable
= selectExpression.Tables.Last(t => t.QuerySource == querySource);
foreach (var property in navigation.ForeignKey.PrincipalKey.Properties)
{
selectExpression
.AddToOrderBy(
_relationalAnnotationProvider.For(property).ColumnName,
property,
principalTable,
OrderingDirection.Asc);
}
var targetSelectExpression = _selectExpressionFactory.Create();
targetTableExpression
= new TableExpression(
targetTableName,
_relationalAnnotationProvider.For(targetEntityType).Schema,
targetTableAlias,
querySource);
targetSelectExpression.AddTable(targetTableExpression);
var materializer
= _materializerFactory
.CreateMaterializer(
targetEntityType,
targetSelectExpression,
(p, se) => se.AddToProjection(
_relationalAnnotationProvider.For(p).ColumnName,
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();
var innerJoinExpression = targetSelectExpression.AddInnerJoin(innerJoinSelectExpression);
LiftOrderBy(innerJoinSelectExpression, targetSelectExpression, innerJoinExpression);
innerJoinExpression.Predicate
= BuildJoinEqualityExpression(
navigation,
targetTableExpression,
innerJoinExpression,
querySource);
selectExpression = targetSelectExpression;
yield return
(Expression.Lambda(
Expression.Call(
_queryCompilationContext.QueryMethodProvider
.CreateCollectionIncludeRelatedValuesStrategyMethod,
Expression.Call(
_queryCompilationContext.QueryMethodProvider.QueryMethod,
EntityQueryModelVisitor.QueryContextParameter,
Expression.Constant(
_commandBuilderFactory.Create(
() => _sqlQueryGeneratorFactory
.CreateGenerator(targetSelectExpression))),
Expression.Constant(_queryCompilationContext.Logger),
Expression.Constant(queryIndex, typeof(int?))),
materializer)));
}
}
}