attempt to build more interesting SQL queries

Subcommits:

fix old iterator, and flesh out new builder iterator

fix contains for builder iterator

Working replacement iterator

graph/sql/builder_iterator_test.go

@@ -0,0 +1,110 @@
+// Copyright 2015 The Cayley Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sql
+
+import (
+	"flag"
+	"fmt"
+	"testing"
+
+	"github.com/google/cayley/graph"
+	"github.com/google/cayley/graph/iterator"
+	"github.com/google/cayley/quad"
+)
+
+var dbpath = flag.String("dbpath", "", "Path to running DB")
+
+func TestSimpleSQL(t *testing.T) {
+	it := NewStatementIterator(nil, quad.Object, "cool")
+	s, v := it.buildQuery(false, nil)
+	fmt.Println(s, v)
+}
+
+// Functional tests
+
+func TestQuadIteration(t *testing.T) {
+	if *dbpath == "" {
+		t.SkipNow()
+	}
+	db, err := newQuadStore(*dbpath, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	it := NewStatementIterator(db.(*QuadStore), quad.Object, "Humphrey Bogart")
+	for graph.Next(it) {
+		fmt.Println(it.Result())
+	}
+	it = NewStatementIterator(db.(*QuadStore), quad.Subject, "/en/casablanca_1942")
+	s, v := it.buildQuery(false, nil)
+	fmt.Println(s, v)
+	c := 0
+	for graph.Next(it) {
+		fmt.Println(it.Result())
+		c += 1
+	}
+	if c != 18 {
+		t.Errorf("Not enough results, got %d expected 18")
+	}
+}
+
+func TestNodeIteration(t *testing.T) {
+	if *dbpath == "" {
+		t.SkipNow()
+	}
+	db, err := newQuadStore(*dbpath, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	it := &StatementIterator{
+		uid:    iterator.NextUID(),
+		qs:     db.(*QuadStore),
+		stType: node,
+		dir:    quad.Object,
+		tags: []tag{
+			tag{
+				pair: tableDir{
+					table: "t_4",
+					dir:   quad.Subject,
+				},
+				t: "x",
+			},
+		},
+		where: baseClause{
+			pair: tableDir{
+				table: "t_4",
+				dir:   quad.Subject,
+			},
+			strTarget: []string{"/en/casablanca_1942"},
+		},
+	}
+	s, v := it.buildQuery(false, nil)
+	it.Tagger().Add("id")
+	fmt.Println(s, v)
+	for graph.Next(it) {
+		fmt.Println(it.Result())
+		out := make(map[string]graph.Value)
+		it.TagResults(out)
+		for k, v := range out {
+			fmt.Printf("%s: %v\n", k, v.(string))
+		}
+	}
+	contains := it.Contains("Casablanca")
+	s, v = it.buildQuery(true, "Casablanca")
+	fmt.Println(s, v)
+	it.Tagger().Add("id")
+	if !contains {
+		t.Error("Didn't contain Casablanca")
+	}
+}

graph/sql/iterator.go

@@ -199,10 +199,12 @@ func (it *Iterator) Next() bool {
 func (it *Iterator) Contains(v graph.Value) bool {
 	graph.ContainsLogIn(it, v)
 	if it.isAll {
+		it.result = v
 		return graph.ContainsLogOut(it, v, true)
 	}
 	q := v.(quad.Quad)
 	if q.Get(it.dir) == it.val.(string) {
+		it.result = v
 		return graph.ContainsLogOut(it, v, true)
 	}
 	return graph.ContainsLogOut(it, v, false)
@@ -217,6 +219,9 @@ func (it *Iterator) Size() (int64, bool) {
 }
 
 func (it *Iterator) Result() graph.Value {
+	if it.result == nil {
+		glog.Fatalln("result was nil", it)
+	}
 	return it.result
 }
 
@@ -239,7 +244,7 @@ func (it *Iterator) Type() graph.Type {
 	return sqlType
 }
 
-func (it *Iterator) Sorted() bool                     { return true }
+func (it *Iterator) Sorted() bool                     { return false }
 func (it *Iterator) Optimize() (graph.Iterator, bool) { return it, false }
 
 func (it *Iterator) Describe() graph.Description {

graph/sql/quadstore.go

@@ -200,7 +200,7 @@ func (qs *QuadStore) Quad(val graph.Value) quad.Quad {
 }
 
 func (qs *QuadStore) QuadIterator(d quad.Direction, val graph.Value) graph.Iterator {
-	return NewIterator(qs, d, val)
+	return NewStatementIterator(qs, d, val.(string))
 }
 
 func (qs *QuadStore) NodesAllIterator() graph.Iterator {