protected override Expression VisitProjection(ProjectionExpression proj)
{
this.Visit(proj.Projector);
return(proj);
}
public override ProjectionExpression GetQueryExpression(MappingEntity entity)
{
var tables = this.mapping.GetTables(entity);
if (tables.Count <= 1)
{
return(base.GetQueryExpression(entity));
}
var aliases = new Dictionary <string, TableAlias>();
MappingTable rootTable = tables.Single(ta => !this.mapping.IsExtensionTable(ta));
var tex = new TableExpression(new TableAlias(), entity, this.mapping.GetTableName(rootTable));
aliases.Add(this.mapping.GetAlias(rootTable), tex.Alias);
Expression source = tex;
foreach (MappingTable table in tables.Where(t => this.mapping.IsExtensionTable(t)))
{
TableAlias joinedTableAlias = new TableAlias();
string extensionAlias = this.mapping.GetAlias(table);
aliases.Add(extensionAlias, joinedTableAlias);
List <string> keyColumns = this.mapping.GetExtensionKeyColumnNames(table).ToList();
List <MemberInfo> relatedMembers = this.mapping.GetExtensionRelatedMembers(table).ToList();
string relatedAlias = this.mapping.GetExtensionRelatedAlias(table);
TableAlias relatedTableAlias;
aliases.TryGetValue(relatedAlias, out relatedTableAlias);
TableExpression joinedTex = new TableExpression(joinedTableAlias, entity, this.mapping.GetTableName(table));
Expression cond = null;
for (int i = 0, n = keyColumns.Count; i < n; i++)
{
var memberType = TypeHelper.GetMemberType(relatedMembers[i]);
var colType = this.GetColumnType(entity, relatedMembers[i]);
var relatedColumn = new ColumnExpression(memberType, colType, relatedTableAlias, this.mapping.GetColumnName(entity, relatedMembers[i]));
var joinedColumn = new ColumnExpression(memberType, colType, joinedTableAlias, keyColumns[i]);
var eq = joinedColumn.Equal(relatedColumn);
cond = (cond != null) ? cond.And(eq) : eq;
}
source = new JoinExpression(JoinType.SingletonLeftOuter, source, joinedTex, cond);
}
var columns = new List <ColumnDeclaration>();
this.GetColumns(entity, aliases, columns);
SelectExpression root = new SelectExpression(new TableAlias(), columns, source, null);
var existingAliases = aliases.Values.ToArray();
Expression projector = this.GetEntityExpression(root, entity);
var selectAlias = new TableAlias();
var pc = ColumnProjector.ProjectColumns(this.Translator.Linguist.Language, projector, null, selectAlias, root.Alias);
var proj = new ProjectionExpression(
new SelectExpression(selectAlias, pc.Columns, root, null),
pc.Projector
);
return((ProjectionExpression)this.Translator.Police.ApplyPolicy(proj, entity.ElementType));
}
protected override Expression VisitProjection(ProjectionExpression proj)
{
this.found = proj;
return(proj);
}
protected override Expression VisitProjection(ProjectionExpression proj)
{
SelectExpression select = (SelectExpression)this.Visit(proj.Select);
return(this.UpdateProjection(proj, select, proj.Projector, proj.Aggregator));
}
protected virtual Expression GetInsertResult(MappingEntity entity, Expression instance, LambdaExpression selector, Dictionary <MemberInfo, Expression> map)
{
var tableAlias = new TableAlias();
var tex = new TableExpression(tableAlias, 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 ColumnExpression(mex.Type, genIdCommand.Variables[0].QueryType, genIdCommand.Source.Alias, genIdCommand.Source.Columns[0].Name),
aggregator
));
}
else
{
TableAlias alias = new TableAlias();
var colType = this.GetColumnType(entity, mex.Member);
return(new ProjectionExpression(
new SelectExpression(alias, new[] { new ColumnDeclaration("", map[mex.Member], colType) }, null, null),
new ColumnExpression(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);
TableAlias newAlias = new TableAlias();
var pc = ColumnProjector.ProjectColumns(this.translator.Linguist.Language, selection, null, newAlias, tableAlias);
var pe = new ProjectionExpression(
new SelectExpression(newAlias, pc.Columns, tex, where),
pc.Projector,
aggregator
);
if (genIdCommand != null)
{
return(new BlockCommand(genIdCommand, pe));
}
return(pe);
}
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)ColumnMapper.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;
TableAlias newAlias = new TableAlias();
var pc = ColumnProjector.ProjectColumns(this.language, newProjector, null, newAlias, newOuterSelect.Alias, newInnerSelect.Alias);
JoinExpression join = new JoinExpression(JoinType.OuterApply, newOuterSelect, newInnerSelect, null);
SelectExpression joinedSelect = new SelectExpression(newAlias, pc.Columns, 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 column 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 => ColumnMapper.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 => ColumnMapper.Map(k, joinedSelect.Alias, ((ColumnExpression)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;
}
}
