public ClientJoinExpression(ProjectionExpression projection, IEnumerable<Expression> outerKey, IEnumerable<Expression> innerKey)
: base(DbExpressionType.ClientJoin, projection.Type)
{
this.outerKey = outerKey.ToReadOnly();
this.innerKey = innerKey.ToReadOnly();
this.projection = projection;
}
public OUpdateCommandExpression(IdentifiableExpression identifiable, Expression where, IEnumerable<FieldAssignment> assignments, Expression projector)
: base(identifiable, where, assignments)
{
Projection = new ProjectionExpression(null,
projector,
Aggregator.GetAggregator(projector.Type, typeof(IEnumerable<>).MakeGenericType(projector.Type)));
}
public virtual ProjectionExpression AddOuterJoinTest(ProjectionExpression proj)
{
var test = this.GetOuterJoinTest(proj.Select);
var select = proj.Select;
FieldExpression testCol = null;
// look to see if test expression exists in fields already
foreach (var col in select.Fields)
{
if (test.Equals(col.Expression))
{
var colType = this.TypeSystem.GetStorageType(test.Type);
testCol = new FieldExpression(test.Type, colType, select.Alias, col.Name);
break;
}
}
if (testCol == null)
{
// add expression to projection
testCol = test as FieldExpression;
string colName = (testCol != null) ? testCol.Name : "Test";
colName = proj.Select.Fields.GetAvailableFieldName(colName);
var colType = this.TypeSystem.GetStorageType(test.Type);
select = select.AddField(new FieldDeclaration(colName, test, colType));
testCol = new FieldExpression(test.Type, colType, select.Alias, colName);
}
var newProjector = new OuterJoinedExpression(testCol, proj.Projector);
return new ProjectionExpression(select, newProjector, proj.Aggregator);
}
protected ClientJoinExpression UpdateClientJoin(ClientJoinExpression join, ProjectionExpression projection, IEnumerable<Expression> outerKey, IEnumerable<Expression> innerKey)
{
if (projection != join.Projection || outerKey != join.OuterKey || innerKey != join.InnerKey)
{
return new ClientJoinExpression(projection, outerKey, innerKey);
}
return join;
}
protected virtual UpdateCommandExpression UpdateUpdate(OUpdateCommandExpression update, IdentifiableExpression table, Expression where,
IEnumerable<FieldAssignment> assignments, ProjectionExpression projection)
{
if (table != update.Identifiable || where != update.Where || assignments != update.Assignments || projection.Projector != update.Projection.Projector)
{
return new OUpdateCommandExpression(table, where, assignments, projection.Projector);
}
return update;
}
protected virtual InsertCommandExpression UpdateInsert(OInsertCommandExpression insert, IdentifiableExpression table,
IEnumerable<FieldAssignment> assignments, ProjectionExpression projection)
{
if (table != insert.Identifiable || assignments != insert.Assignments || projection.Projector != insert.Projection.Projector)
{
return new OInsertCommandExpression(table, assignments, projection.Projector);
}
return insert;
}
protected override Expression VisitProjection(ProjectionExpression proj)
{
proj = (ProjectionExpression)base.VisitProjection(proj);
if (proj.Select.From is SelectExpression)
{
List<SelectExpression> redundant = RedundantSubqueryGatherer.Gather(proj.Select);
if (redundant != null)
{
proj = SubqueryRemover.Remove(proj, redundant);
}
}
return proj;
}
protected override Expression VisitProjection(ProjectionExpression proj)
{
if (isTopLevel)
{
isTopLevel = false;
this.currentSelect = proj.Select;
Expression projector = this.Visit(proj.Projector);
if (projector != proj.Projector || this.currentSelect != proj.Select)
{
return new ProjectionExpression(this.currentSelect, projector, proj.Aggregator);
}
return proj;
}
if (proj.IsSingleton && this.CanJoinOnServer(this.currentSelect))
{
IdentifiableAlias newAlias = new IdentifiableAlias();
this.currentSelect = this.currentSelect.AddRedundantSelect(this.language, newAlias);
// remap any references to the outer select to the new alias;
SelectExpression source = (SelectExpression)FieldMapper.Map(proj.Select, newAlias, this.currentSelect.Alias);
// add outer-join test
ProjectionExpression pex = this.language.AddOuterJoinTest(new ProjectionExpression(source, proj.Projector));
var pc = FieldProjector.ProjectFields(this.language, pex.Projector, this.currentSelect.Fields, this.currentSelect.Alias, newAlias, proj.Select.Alias);
JoinExpression join = new JoinExpression(JoinType.OuterApply, this.currentSelect.From, pex.Select, null);
this.currentSelect = new SelectExpression(this.currentSelect.Alias, pc.Fields, join, null);
return this.Visit(pc.Projector);
}
var saveTop = this.isTopLevel;
var saveSelect = this.currentSelect;
this.isTopLevel = true;
this.currentSelect = null;
Expression result = base.VisitProjection(proj);
this.isTopLevel = saveTop;
this.currentSelect = saveSelect;
return result;
}
protected ProjectionExpression UpdateProjection(ProjectionExpression proj, SelectExpression select, Expression projector, LambdaExpression aggregator)
{
if (select != proj.Select || projector != proj.Projector || aggregator != proj.Aggregator)
{
return new ProjectionExpression(select, projector, aggregator);
}
return proj;
}
public static ProjectionExpression Remove(ProjectionExpression projection, IEnumerable<SelectExpression> selectsToRemove)
{
return (ProjectionExpression)new OSubqueryRemover(selectsToRemove).Visit(projection);
}
public static ProjectionExpression Remove(ProjectionExpression projection, params SelectExpression[] selectsToRemove)
{
return Remove(projection, (IEnumerable<SelectExpression>)selectsToRemove);
}
protected override Expression VisitProjection(ProjectionExpression proj)
{
Expression projector = this.Visit(proj.Projector);
return this.UpdateProjection(proj, proj.Select, projector, proj.Aggregator);
}
protected virtual bool CompareProjection(ProjectionExpression a, ProjectionExpression b)
{
if (!this.Compare(a.Select, b.Select))
return false;
var save = this.aliasScope;
try
{
this.aliasScope = new ScopedDictionary<IdentifiableAlias, IdentifiableAlias>(this.aliasScope);
this.aliasScope.Add(a.Select.Alias, b.Select.Alias);
return this.Compare(a.Projector, b.Projector)
&& this.Compare(a.Aggregator, b.Aggregator)
&& a.IsSingleton == b.IsSingleton;
}
finally
{
this.aliasScope = save;
}
}
public override ProjectionExpression GetQueryExpression(IMappedEntity entity)
{
var IdentifiableAlias = new IdentifiableAlias();
var selectAlias = new IdentifiableAlias();
var table = new IdentifiableExpression(IdentifiableAlias, entity, this.mapping.GetTableName(entity));
Expression projector = this.GetEntityExpression(table, entity);
var pc = FieldProjector.ProjectFields(this.translator.Linguist.Language, projector, null, selectAlias, IdentifiableAlias);
var proj = new ProjectionExpression(
new SelectExpression(selectAlias, pc.Fields, table, null),
pc.Projector
);
return (ProjectionExpression)this.Translator.Police.ApplyPolicy(proj, entity.EntityType);
}
protected override Expression VisitProjection(ProjectionExpression projection)
{
// visit mapping in reverse order
Expression projector = this.Visit(projection.Projector);
SelectExpression select = (SelectExpression)this.Visit(projection.Select);
return this.UpdateProjection(projection, select, projector, projection.Aggregator);
}
protected override Expression VisitProjection(ProjectionExpression proj)
{
this.Visit(proj.Projector);
return proj;
}
protected virtual Expression BindGroupBy(Expression source, LambdaExpression keySelector, LambdaExpression elementSelector, LambdaExpression resultSelector)
{
ProjectionExpression projection = this.VisitSequence(source);
this.map[keySelector.Parameters[0]] = projection.Projector;
Expression keyExpr = this.Visit(keySelector.Body);
Expression elemExpr = projection.Projector;
if (elementSelector != null)
{
this.map[elementSelector.Parameters[0]] = projection.Projector;
elemExpr = this.Visit(elementSelector.Body);
}
// Use ProjectFields to get group-by expressions from key expression
ProjectedFields keyProjection = this.ProjectFields(keyExpr, projection.Select.Alias, projection.Select.Alias);
var groupExprs = keyProjection.Fields.Select(c => c.Expression).ToArray();
// make duplicate of source query as basis of element subquery by visiting the source again
ProjectionExpression subqueryBasis = this.VisitSequence(source);
// recompute key fields for group expressions relative to subquery (need these for doing the correlation predicate)
this.map[keySelector.Parameters[0]] = subqueryBasis.Projector;
Expression subqueryKey = this.Visit(keySelector.Body);
// use same projection trick to get group-by expressions based on subquery
ProjectedFields subqueryKeyPC = this.ProjectFields(subqueryKey, subqueryBasis.Select.Alias, subqueryBasis.Select.Alias);
var subqueryGroupExprs = subqueryKeyPC.Fields.Select(c => c.Expression).ToArray();
Expression subqueryCorrelation = this.BuildPredicateWithNullsEqual(subqueryGroupExprs, groupExprs);
// compute element based on duplicated subquery
Expression subqueryElemExpr = subqueryBasis.Projector;
if (elementSelector != null)
{
this.map[elementSelector.Parameters[0]] = subqueryBasis.Projector;
subqueryElemExpr = this.Visit(elementSelector.Body);
}
// build subquery that projects the desired element
var elementAlias = this.GetNextAlias();
ProjectedFields elementPC = this.ProjectFields(subqueryElemExpr, elementAlias, subqueryBasis.Select.Alias);
ProjectionExpression elementSubquery =
new ProjectionExpression(
new SelectExpression(elementAlias, elementPC.Fields, subqueryBasis.Select, subqueryCorrelation),
elementPC.Projector
);
var alias = this.GetNextAlias();
// make it possible to tie aggregates back to this group-by
GroupByInfo info = new GroupByInfo(alias, elemExpr);
this.groupByMap.Add(elementSubquery, info);
Expression resultExpr;
if (resultSelector != null)
{
Expression saveGroupElement = this.currentGroupElement;
this.currentGroupElement = elementSubquery;
// compute result expression based on key & element-subquery
this.map[resultSelector.Parameters[0]] = keyProjection.Projector;
this.map[resultSelector.Parameters[1]] = elementSubquery;
resultExpr = this.Visit(resultSelector.Body);
this.currentGroupElement = saveGroupElement;
}
else
{
// result must be IGrouping<K,E>
resultExpr =
Expression.New(
typeof(Grouping<,>).MakeGenericType(keyExpr.Type, subqueryElemExpr.Type).GetConstructors()[0],
new Expression[] { keyExpr, elementSubquery }
);
resultExpr = Expression.Convert(resultExpr, typeof(IGrouping<,>).MakeGenericType(keyExpr.Type, subqueryElemExpr.Type));
}
ProjectedFields pc = this.ProjectFields(resultExpr, alias, projection.Select.Alias);
// make it possible to tie aggregates back to this group-by
NewExpression newResult = this.GetNewExpression(pc.Projector);
if (newResult != null && newResult.Type.IsGenericType && newResult.Type.GetGenericTypeDefinition() == typeof(Grouping<,>))
{
Expression projectedElementSubquery = newResult.Arguments[1];
this.groupByMap.Add(projectedElementSubquery, info);
}
return new ProjectionExpression(
new SelectExpression(alias, pc.Fields, projection.Select, null, null, groupExprs),
pc.Projector
);
}
protected override Expression VisitProjection(ProjectionExpression proj)
{
SelectExpression save = this.currentSelect;
this.currentSelect = proj.Select;
try
{
if (!this.isTopLevel)
{
if (this.CanJoinOnClient(this.currentSelect))
{
// make a query that combines all the constraints from the outer queries into a single select
SelectExpression newOuterSelect = (SelectExpression)QueryDuplicator.Duplicate(save);
// remap any references to the outer select to the new alias;
SelectExpression newInnerSelect = (SelectExpression)FieldMapper.Map(proj.Select, newOuterSelect.Alias, save.Alias);
// add outer-join test
ProjectionExpression newInnerProjection = this.language.AddOuterJoinTest(new ProjectionExpression(newInnerSelect, proj.Projector));
newInnerSelect = newInnerProjection.Select;
Expression newProjector = newInnerProjection.Projector;
IdentifiableAlias newAlias = new IdentifiableAlias();
var pc = FieldProjector.ProjectFields(this.language, newProjector, null, newAlias, newOuterSelect.Alias, newInnerSelect.Alias);
JoinExpression join = new JoinExpression(JoinType.OuterApply, newOuterSelect, newInnerSelect, null);
SelectExpression joinedSelect = new SelectExpression(newAlias, pc.Fields, join, null, null, null, proj.IsSingleton, null, null, false);
// apply client-join treatment recursively
this.currentSelect = joinedSelect;
newProjector = this.Visit(pc.Projector);
// compute keys (this only works if join condition was a single field comparison)
List<Expression> outerKeys = new List<Expression>();
List<Expression> innerKeys = new List<Expression>();
if (this.GetEquiJoinKeyExpressions(newInnerSelect.Where, newOuterSelect.Alias, outerKeys, innerKeys))
{
// outerKey needs to refer to the outer-scope's alias
var outerKey = outerKeys.Select(k => FieldMapper.Map(k, save.Alias, newOuterSelect.Alias));
// innerKey needs to refer to the new alias for the select with the new join
var innerKey = innerKeys.Select(k => FieldMapper.Map(k, joinedSelect.Alias, ((FieldExpression)k).Alias));
ProjectionExpression newProjection = new ProjectionExpression(joinedSelect, newProjector, proj.Aggregator);
return new ClientJoinExpression(newProjection, outerKey, innerKey);
}
}
else
{
bool saveJoin = this.canJoinOnClient;
this.canJoinOnClient = false;
var result = base.VisitProjection(proj);
this.canJoinOnClient = saveJoin;
return result;
}
}
else
{
this.isTopLevel = false;
}
return base.VisitProjection(proj);
}
finally
{
this.currentSelect = save;
}
}
protected override Expression VisitProjection(ProjectionExpression proj)
{
// treat these like scalar subqueries
if ((proj.Projector is FieldExpression) || this.forDebug)
{
this.Write("(");
this.WriteLine(Indentation.Inner);
this.Visit(proj.Select);
this.Write(")");
this.Indent(Indentation.Outer);
}
else
{
throw new NotSupportedException("Non-scalar projections cannot be translated to SQL.");
}
return proj;
}
protected virtual Expression VisitProjection(ProjectionExpression proj)
{
var select = (SelectExpression)this.Visit(proj.Select);
var projector = this.Visit(proj.Projector);
return this.UpdateProjection(proj, select, projector, proj.Aggregator);
}
protected virtual Expression GetInsertResult(IMappedEntity entity, Expression instance, LambdaExpression selector, Dictionary<MemberInfo, Expression> map)
{
var IdentifiableAlias = new IdentifiableAlias();
var tex = new IdentifiableExpression(IdentifiableAlias, entity, this.mapping.GetTableName(entity));
var aggregator = Aggregator.GetAggregator(selector.Body.Type, typeof(IEnumerable<>).MakeGenericType(selector.Body.Type));
Expression where;
DeclarationCommand genIdCommand = null;
var generatedIds = this.mapping.GetMappedMembers(entity).Where(m => this.mapping.IsPrimaryKey(entity, m) && this.mapping.IsGenerated(entity, m)).ToList();
if (generatedIds.Count > 0)
{
if (map == null || !generatedIds.Any(m => map.ContainsKey(m)))
{
var localMap = new Dictionary<MemberInfo, Expression>();
genIdCommand = this.GetGeneratedIdCommand(entity, generatedIds.ToList(), localMap);
map = localMap;
}
// is this just a retrieval of one generated id member?
var mex = selector.Body as MemberExpression;
if (mex != null && this.mapping.IsPrimaryKey(entity, mex.Member) && this.mapping.IsGenerated(entity, mex.Member))
{
if (genIdCommand != null)
{
// just use the select from the genIdCommand
return new ProjectionExpression(
genIdCommand.Source,
new FieldExpression(mex.Type, genIdCommand.Variables[0].QueryType, genIdCommand.Source.Alias, genIdCommand.Source.Fields[0].Name),
aggregator
);
}
else
{
IdentifiableAlias alias = new IdentifiableAlias();
var colType = this.GetFieldType(entity, mex.Member);
return new ProjectionExpression(
new SelectExpression(alias, new[] { new FieldDeclaration("", map[mex.Member], colType) }, null, null),
new FieldExpression(TypeHelper.GetMemberType(mex.Member), colType, alias, ""),
aggregator
);
}
}
where = generatedIds.Select((m, i) =>
this.GetMemberExpression(tex, entity, m).Equal(map[m])
).Aggregate((x, y) => x.And(y));
}
else
{
where = this.GetIdentityCheck(tex, entity, instance);
}
Expression typeProjector = this.GetEntityExpression(tex, entity);
Expression selection = DbExpressionReplacer.Replace(selector.Body, selector.Parameters[0], typeProjector);
IdentifiableAlias newAlias = new IdentifiableAlias();
var pc = FieldProjector.ProjectFields(this.translator.Linguist.Language, selection, null, newAlias, IdentifiableAlias);
var pe = new ProjectionExpression(
new SelectExpression(newAlias, pc.Fields, tex, where),
pc.Projector,
aggregator
);
if (genIdCommand != null)
{
return new BlockCommandExpression(genIdCommand, pe);
}
return pe;
}
protected virtual Expression VisitProjection(ProjectionExpression projection)
{
this.AddAlias(projection.Select.Alias);
this.Write("Project(");
this.WriteLine(Indentation.Inner);
this.Write("@\"");
this.Visit(projection.Select);
this.Write("\",");
this.WriteLine(Indentation.Same);
this.Visit(projection.Projector);
this.Write(",");
this.WriteLine(Indentation.Same);
this.Visit(projection.Aggregator);
this.WriteLine(Indentation.Outer);
this.Write(")");
return projection;
}
private Expression BindFirst(Expression source, LambdaExpression predicate, string kind, bool isRoot)
{
ProjectionExpression projection = this.VisitSequence(source);
Expression where = null;
if (predicate != null)
{
this.map[predicate.Parameters[0]] = projection.Projector;
where = this.Visit(predicate.Body);
}
bool isFirst = kind.StartsWith("First");
bool isLast = kind.StartsWith("Last");
Expression take = (isFirst || isLast) ? Expression.Constant(1) : null;
if (take != null || where != null)
{
var alias = this.GetNextAlias();
ProjectedFields pc = this.ProjectFields(projection.Projector, alias, projection.Select.Alias);
projection = new ProjectionExpression(
new SelectExpression(alias, pc.Fields, projection.Select, where, null, null, false, null, take, isLast),
pc.Projector
);
}
if (isRoot)
{
Type elementType = projection.Projector.Type;
ParameterExpression p = Expression.Parameter(typeof(IEnumerable<>).MakeGenericType(elementType), "p");
LambdaExpression gator = Expression.Lambda(Expression.Call(typeof(Enumerable), kind, new Type[] { elementType }, p), p);
return new ProjectionExpression(projection.Select, projection.Projector, gator);
}
return projection;
}
public override Expression GetMemberExpression(Expression root, IMappedEntity entity, MemberInfo member)
{
if (this.mapping.IsAssociationRelationship(entity, member))
{
var relatedEntity = this.mapping.GetRelatedEntity(entity, member);
ProjectionExpression projection = this.GetQueryExpression(relatedEntity);
// make where clause for joining back to 'root'
var declaredTypeMembers = this.mapping.GetAssociationKeyMembers(entity, member).ToList();
var associatedMembers = this.mapping.GetAssociationRelatedKeyMembers(entity, member).ToList();
Expression where = null;
for (int i = 0, n = associatedMembers.Count; i < n; i++)
{
Expression equal =
this.GetMemberExpression(projection.Projector, relatedEntity, associatedMembers[i]).Equal(
this.GetMemberExpression(root, entity, declaredTypeMembers[i])
);
where = (where != null) ? where.And(equal) : equal;
}
IdentifiableAlias newAlias = new IdentifiableAlias();
var pc = FieldProjector.ProjectFields(this.translator.Linguist.Language, projection.Projector, null, newAlias, projection.Select.Alias);
LambdaExpression aggregator = Aggregator.GetAggregator(TypeHelper.GetMemberType(member), typeof(IEnumerable<>).MakeGenericType(pc.Projector.Type));
var result = new ProjectionExpression(
new SelectExpression(newAlias, pc.Fields, projection.Select, where),
pc.Projector, aggregator
);
return this.translator.Police.ApplyPolicy(result, member);
}
else
{
AliasedExpression aliasedRoot = root as AliasedExpression;
if (aliasedRoot != null && this.mapping.IsField(entity, member))
{
return new FieldExpression(TypeHelper.GetMemberType(member),
this.GetFieldType(entity, member),
aliasedRoot.Alias,
this.mapping.GetFieldName(entity, member));
}
return QueryBinder.BindMember(root, member);
}
}
protected override Expression ExecuteProjection(ProjectionExpression projection, QueryCommand command, Expression[] values)
{
var saveScope = this.Scope;
ParameterExpression reader = Expression.Parameter(typeof(FieldReader), "r" + nReaders++);
this.Scope = new BuilderScope(this.Scope, reader, projection.Select.Alias, projection.Select.Fields)
{
UseOrdinalMapping = false // orient cannot guarantee ordinally mapped results - must map by name
};
var projector = RedirectProjector(projection.Projector, reader, true);
this.Scope = saveScope;
var entity = EntityFinder.Find(projection.Projector);
if (entity != null && entity.EntityType == typeof(_Thing))
{
entity = new OMappingEntity(typeof(IIdentifiable),_repoType);
}
string methExecute = "Execute";
// call low-level execute directly on supplied DbQueryProvider
Expression result = Expression.Call(this.Executor, methExecute, new Type[] { projector.Body.Type },
Expression.Constant(command),
projector,
Expression.Constant(entity, typeof(MappingEntity)),
Expression.NewArrayInit(typeof(object), values)
);
if (projection.Aggregator != null)
{
if (projector.ReturnType != projection.Aggregator.Parameters[0].Type.GetGenericArguments()[0])
{
// we probably swaped out an Identifiable type for IIdentifiable, so we need to rebuild the projection
// using the interface, otherwise we'll get cast failures downstream
projection = new ProjectionExpression(
projection.Select,
projector,
Aggregator.GetAggregator(projector.ReturnType,
projection.Aggregator.Parameters[0].Type.GetGenericTypeDefinition().MakeGenericType(projector.ReturnType)));
}
// apply aggregator
result = DbExpressionReplacer.Replace(projection.Aggregator.Body, projection.Aggregator.Parameters[0], result);
}
return result;
}
