public override Evaluant.NLinq.Expressions.QueryBodyClause Visit(NLinq.Expressions.FromClause expression)
{
TableAlias alias;
if (entityIdentifierAliases.TryGetValue(expression.Identifier.Text, out alias))
{
if (alias != ((EntityIdentifier)expression.Identifier).Entity.Alias)
throw new NotSupportedException("The same identifier refers to a different Alias");
}
else
entityIdentifierAliases.Add(expression.Identifier.Text, ((EntityIdentifier)expression.Identifier).Entity.Alias);
if (expression.Type != null)
{
IAliasedExpression src;
if (expression.Type.StartsWith("System."))
src = ((EntityIdentifier)expression.Identifier).Entity;
else
src = new SqlExpressions.Mapping.EntitySourceExpression(((EntityIdentifier)expression.Identifier).Entity.Alias, expression.Type);
if (select.From == null)
select.From = new FromClause(src);
else
select.From = new FromClause(
new JoinedTableExpression(
select.From[0],
src,
new Evaluant.NLinq.Expressions.BinaryExpression(
Evaluant.NLinq.Expressions.BinaryExpressionType.Unknown,
expression.Identifier,
Visit(expression.Expression))
)
);
}
else
{
SelectStatement currentSelect = select;
var result = Visit(expression.Expression);
if (select != currentSelect)
{
select = (SelectStatement)new LazyAliasResolver(new Dictionary<TableAlias, TableAlias> { { select.Alias, ((EntityIdentifier)expression.Identifier).Entity.Alias } }).Visit(select);
if (currentSelect.From == null)
currentSelect.From = new FromClause(select);
else
currentSelect.From = new FromClause(
new JoinedTableExpression(
currentSelect.From[0],
select,
new NLinq.Expressions.BinaryExpression(
NLinq.Expressions.BinaryExpressionType.Unknown,
expression.Identifier,
result)
)
);
}
select = currentSelect;
}
return expression;
}
public DiscriminatorMutator(SqlExpressions.Mapping.EntitySourceExpression ese)
{
this.ese = ese;
}