// basic samples, operators return relations
static void SampleWithTypes()
{
Show("Seq", RelSequenceST.Create(5));
Show("SP", Supplier.SP);
var v1 = new RelVarST <TupS>(Supplier.S);
var v2 = new RelVarST <Tup1>(v1.Value
.Restrict(t => t.Status == 30)
.Rename <TupSX>() // "SNo", "SName", "Status", "Supplier City"
.Project <Tup1>()); // "Supplier City"
Show("v2", v2.Value);
Show("Extend", Supplier.S
.Extend <TupSX>(t => "XXX") // "SNo", "SName", "Status", "Supplier City"
);
Show("Join", Supplier.P
.Rename <TupPcolour>() // "PNo", "PName", "Colour", "Weight", "City"
.Restrict(t => t.Colour == "Red")
.Project <TupPPno>() // "PNo", "PName"
.Join <TupSP, TupPjoin>(Supplier.SP) // "PNo", "PName", "SNo", "Qty"
);
Show("Aggregation", Supplier.SP
.Aggregate <TupAgg, int>((t, a) => a + t.Qty) // "PNo", "TotQty"
);
var seed = MMQData.MMQ.Extend <TupMMQA>(t => t.Qty); // "Major", "Minor", "Qty", "AggQty"
var zmq = MMQData.MMQ.Rename <TupzMQ>(); // "zmatch", "Minor", "Qty"
var exp = seed.While <RelMMQA>(t => t
.Rename <TupMzA>() // "Major", "zmatch", "ExpQty"
.Join <TupzMQ, TupMMQA>(zmq)
.Transform <TupMMQA>(tt => TupMMQA.Create(tt.Major, tt.Minor, 0, tt.AggQty * tt.Qty)));
Show("While", exp);
Show("P1 -> P5", exp
.Restrict(t => t.Major == "P1" && t.Minor == "P5")
.Aggregate <TupMMT, int>((t, a) => a + t.AggQty));
v1.Insert(
RelS.Create <RelS>(
new List <TupS> {
TupS.Create("S6", "White", 25, "Paris"),
TupS.Create("S7", "Black", 15, "London"),
})
);
Show("Insert P6 P7", v1);
v1.Update(t => t.City == "Paris", t => TupS.Create(t.SNo, t.SName, t.Status, "Sydney"));
Show("Move to Sydney", v1);
v1.Delete(t => t.City == "Sydney");
Show("Delete Sydneysiders", v1);
}
public static RelSequenceST Create(int count)
{
return(RelSequenceST.Create <RelSequenceST>(Enumerable.Range(0, count).Select(n => TupSequenceST.Create(n))));
}