protected override Expression VisitJoin(SqlJoinExpression join)
{
join = (SqlJoinExpression)base.VisitJoin(join);
if (join.JoinType == SqlJoinType.CrossApply || join.JoinType == SqlJoinType.OuterApply)
{
if (join.Right is SqlTableExpression)
{
return(new SqlJoinExpression(join.Type, SqlJoinType.Cross, join.Left, join.Right, null));
}
else
{
if (@join.Right is SqlSelectExpression @select && select.Take == null && select.Skip == null && !SqlAggregateChecker.HasAggregates(select) && (select.GroupBy == null || select.GroupBy.Count == 0))
{
var selectWithoutWhere = select.ChangeWhere(null);
var referencedAliases = SqlReferencedAliasGatherer.Gather(selectWithoutWhere);
var declaredAliases = SqlDeclaredAliasGatherer.Gather(join.Left);
referencedAliases.IntersectWith(declaredAliases);
if (referencedAliases.Count == 0)
{
var where = select.Where;
select = selectWithoutWhere;
var pc = ColumnProjector.ProjectColumns(new Nominator(Nominator.CanBeColumn), where, select.Columns, select.Alias, SqlDeclaredAliasGatherer.Gather(select.From));
select = select.ChangeColumns(pc.Columns);
where = pc.Projector;
var joinType = (where == null) ? SqlJoinType.Cross : (join.JoinType == SqlJoinType.CrossApply ? SqlJoinType.Inner : SqlJoinType.Left);
return(new SqlJoinExpression(typeof(void), joinType, join.Left, select, where));
}
}
}
}
return(join);
}
public virtual ProjectionExpression GetQueryExpression(IEntityMapping mapping)
{
Expression projector;
TableAlias selectAlias;
ProjectedColumns pc;
ProjectionExpression proj;
var tableAlias = new TableAlias();
selectAlias = new TableAlias();
var table = new TableExpression(tableAlias, mapping);
projector = this.GetEntityExpression(table, mapping);
pc = ColumnProjector.ProjectColumns(projector, null, selectAlias, tableAlias);
proj = new ProjectionExpression(
new SelectExpression(selectAlias, pc.Columns, table, null),
pc.Projector
);
return((ProjectionExpression)ApplyPolicy(proj, mapping.EntityType));
}
protected internal override Expression VisitProjection(ProjectionExpression proj)
{
Expression projector;
SelectExpression select = proj.Select;
using (binder.SetCurrentSource(proj.Select))
projector = this.Visit(proj.Projector);
Alias alias = binder.aliasGenerator.NextSelectAlias();
ProjectedColumns pc = ColumnProjector.ProjectColumns(projector, alias);
projector = pc.Projector;
select = new SelectExpression(alias, false, null, pc.Columns, select, null, null, null, 0);
if (projector != proj.Projector)
{
return(new ProjectionExpression(select, projector, proj.UniqueFunction, proj.Type));
}
return(proj);
}
public virtual Expression GetInsertResult(IEntityMapping mapping, Expression instance, LambdaExpression selector, Dictionary <MemberInfo, Expression> map)
{
var tableAlias = new TableAlias();
var tex = new TableExpression(tableAlias, mapping);
var aggregator = Aggregator.GetAggregator(selector.Body.Type, typeof(IEnumerable <>).MakeGenericType(selector.Body.Type));
Expression where = null;
DeclarationCommand genIdCommand = null;
var generatedIds = mapping.PrimaryKeys.Where(m => m.IsPrimaryKey && m.IsGenerated).ToList();
if (generatedIds.Count > 0)
{
if (map == null || !generatedIds.Any(m => map.ContainsKey(m.Member)))
{
var localMap = new Dictionary <MemberInfo, Expression>();
genIdCommand = this.GetGeneratedIdCommand(mapping, generatedIds, localMap);
map = localMap;
}
// is this just a retrieval of one generated id member?
var mex = selector.Body as MemberExpression;
if (mex != null)
{
var id = mapping.Get(mex.Member);
if (id != null && id.IsPrimaryKey && id.IsGenerated)
{
if (genIdCommand != null)
{
// just use the select from the genIdCommand
return(new ProjectionExpression(
genIdCommand.Source,
new ColumnExpression(mex.Type, genIdCommand.Variables[0].SqlType, genIdCommand.Source.Alias, genIdCommand.Source.Columns[0].Name),
aggregator
));
}
else
{
TableAlias alias = new TableAlias();
var colType = id.SqlType;
return(new ProjectionExpression(
new SelectExpression(alias, new[] { new ColumnDeclaration("", map[mex.Member], colType) }, null, null),
new ColumnExpression(mex.Member.GetMemberType(), colType, alias, ""),
aggregator
));
}
}
where = generatedIds.Select((m, i) =>
this.GetMemberExpression(tex, mapping, m.Member).Equal(map[m.Member])
).Aggregate((x, y) => x.And(y));
}
}
else
{
where = this.GetIdentityCheck(tex, mapping, instance);
}
Expression typeProjector = this.GetEntityExpression(tex, mapping);
Expression selection = DbExpressionReplacer.Replace(selector.Body, selector.Parameters[0], typeProjector);
TableAlias newAlias = new TableAlias();
var pc = ColumnProjector.ProjectColumns(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);
}
/// <summary>
/// Get an expression for a mapped property relative to a root expression.
/// The root is either a TableExpression or an expression defining an entity instance.
/// </summary>
/// <param name="root"></param>
/// <param name="member"></param>
/// <returns></returns>
public virtual Expression GetMemberExpression(Expression root, MemberInfo member)
{
if (IsRelationship(member))
{
Type rowType = GetRelatedType(member);
ProjectionExpression projection = GetTableQuery(rowType);
// make where clause for joining back to 'root'
List <MemberInfo> declaredTypeMembers;
List <MemberInfo> associatedMembers;
GetAssociationKeys(member, out declaredTypeMembers, out associatedMembers);
Expression where = null;
for (int i = 0, n = associatedMembers.Count; i < n; i++)
{
Expression equal = Expression.Equal(
GetMemberExpression(projection.Projector, associatedMembers[i]),
GetMemberExpression(root, declaredTypeMembers[i])
);
where = (where != null) ? Expression.And(where, equal) : equal;
}
TableAlias newAlias = new TableAlias();
var pc = ColumnProjector.ProjectColumns(this.Language.CanBeColumn,
projection.Projector,
null,
newAlias,
projection.Source.Alias);
LambdaExpression aggregator = GetAggregator(TypeHelper.GetMemberType(member),
typeof(IEnumerable <>).MakeGenericType(
pc.Projector.Type));
return(new ProjectionExpression(
new SelectExpression(newAlias, pc.Columns, projection.Source, where),
pc.Projector,
aggregator
));
}
var tableExpression = root as TableExpression;
if (tableExpression != null)
{
if (IsColumn(member))
{
IColumn column = null;
if (tableExpression.Table != null)
{
column = tableExpression.Table.GetColumnByPropertyName(member.Name);
}
var columnName = column != null?GetColumnName(column) : GetColumnName(member);
return(!string.IsNullOrEmpty(columnName)
? new ColumnExpression(column,
TypeHelper.GetMemberType(member),
tableExpression.Alias,
columnName)
: root);
}
return(this.GetTypeProjection(root, TypeHelper.GetMemberType(member)));
}
return(QueryBinder.BindMember(root, member));
}
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;
}
}
