private SqlNode VisitLinkedTable(LinkedTableExpression linkedTable)
{
return TranslateConstantTable(linkedTable.Table, linkedTable.Link);
}
internal SqlNode TranslateLink(SqlLink link, List<SqlExpression> keyExpressions, bool asExpression) {
MetaDataMember mm = link.Member;
if (mm.IsAssociation) {
// Create the row source.
MetaType otherType = mm.Association.OtherType;
Type tableType = otherType.InheritanceRoot.Type;
ITable table = this.services.Context.GetTable(tableType);
Expression source = new LinkedTableExpression(link, table, typeof(IQueryable<>).MakeGenericType(otherType.Type));
// Build key expression nodes.
Expression[] keyExprs = new Expression[keyExpressions.Count];
for (int i = 0; i < keyExpressions.Count; ++i) {
MetaDataMember metaMember = mm.Association.OtherKey[i];
Type memberType = TypeSystem.GetMemberType(metaMember.Member);
keyExprs[i] = InternalExpression.Known(keyExpressions[i], memberType);
}
Expression lex = link.Expression != null
? (Expression)InternalExpression.Known(link.Expression)
: (Expression)Expression.Constant(null, link.Member.Member.DeclaringType);
Expression expr = TranslateAssociation(this.services.Context, mm.Association, source, keyExprs, lex);
// Convert
QueryConverter qc = new QueryConverter(this.services, this.typeProvider, this, this.sql);
SqlSelect sel = (SqlSelect)qc.ConvertInner(expr, link.SourceExpression);
// Turn it into an expression is necessary
SqlNode result = sel;
if (asExpression) {
if (mm.Association.IsMany) {
result = new SqlSubSelect(SqlNodeType.Multiset, link.ClrType, link.SqlType, sel);
}
else {
result = new SqlSubSelect(SqlNodeType.Element, link.ClrType, link.SqlType, sel);
}
}
return result;
}
else {
System.Diagnostics.Debug.Assert(link.Expansion != null);
System.Diagnostics.Debug.Assert(link.KeyExpressions == keyExpressions);
// deferred expression already defined...
return link.Expansion;
}
}