public readonly SDict <long, long> uses; // Item1 is for RIGHT, Item2 for LEFT
public SJoin(ReaderBase f) : base(Types.STableExp, _Join(f))
{
left = f._Get() as SQuery ?? throw new StrongException("Query expected");
outer = f.GetInt() == 1;
joinType = (JoinType)f.GetInt();
right = f._Get() as SQuery ?? throw new StrongException("Query expected");
var n = f.GetInt();
var on = SList <SExpression> .Empty;
var us = SDict <long, long> .Empty;
var tr = (STransaction)f.db;
var lns = SDict <string, long> .Empty;
for (var b = left.Display.First(); b != null; b = b.Next())
{
lns += (b.Value.Item2.Item2, b.Value.Item2.Item1);
}
var rns = SDict <string, long> .Empty;
for (var b = right.Display.First(); b != null; b = b.Next())
{
var nm = b.Value.Item2.Item2;
if (joinType == JoinType.Natural && lns.Contains(nm))
{
us += (b.Value.Item2.Item1, lns[nm]);
}
rns += (nm, b.Value.Item2.Item1);
}
if (joinType.HasFlag(JoinType.Named))
{
for (var i = 0; i < n; i++)
{
var nm = tr.uids[f.GetLong()];
if (!(lns.Contains(nm) && rns.Contains(nm)))
{
throw new StrongException("name " + nm + " not present in Join");
}
us += (rns[nm], lns[nm]);
}
}
else if (!joinType.HasFlag(JoinType.Cross))
{
for (var i = 0; i < n; i++)
{
var e = f._Get() as SExpression
?? throw new StrongException("ON exp expected");
on += e;
}
}
ons = on;
uses = us;
f.context = this;
}
public SJoin(SDatabase db, Reader f) : base(Types.STableExp, _Join(db, f))
{
left = f._Get(db) as SQuery ?? throw new Exception("Query expected");
outer = f.GetInt() == 1;
joinType = (JoinType)f.GetInt();
right = f._Get(db) as SQuery ?? throw new Exception("Query expected");
var n = f.GetInt();
var on = SList <SExpression> .Empty;
var us = SList <string> .Empty;
if (joinType.HasFlag(JoinType.Natural))
{
for (var lb = left.names.First(); lb != null; lb = lb.Next())
{
if (right.names.Contains(lb.Value.Item1))
{
us += lb.Value.Item1;
}
}
}
else if (joinType.HasFlag(JoinType.Named))
{
for (var i = 0; i < n; i++)
{
us += f.GetString();
}
}
else if (!joinType.HasFlag(JoinType.Cross))
{
for (var i = 0; i < n; i++)
{
var e = f._Get(db) as SExpression
?? throw new Exception("ON exp expected");
on += e;
}
}
ons = on;
uses = us;
}