Add full text search support using TSV indexes

docs/guide.md

@@ -132,6 +132,16 @@ query {
 }
 ```
 
+Postgres also supports full text search using a TSV index. Super Graph makes it easy to use this full text search capability using the `search` argument.
+
+```graphql
+query {
+  products(seasrch "amazing") {
+    name
+  }
+}
+```
+
 Super Graph support complex queries where you can add filters, ordering,offsets and limits on the query.
 
 #### Logical Operators

example/db/migrate/20190405042247_add_search_column.rb

@@ -0,0 +1,33 @@
+class AddSearchColumn < ActiveRecord::Migration[5.1]
+  def self.up
+    add_column :products, :tsv, :tsvector
+    add_index :products, :tsv, using: "gin"
+
+    say_with_time("Adding trigger to update the ts_vector column") do
+      execute <<-SQL
+        CREATE FUNCTION products_tsv_trigger() RETURNS trigger AS $$
+        begin
+          new.tsv :=
+          setweight(to_tsvector('pg_catalog.english', coalesce(new.name,'')), 'A') ||
+          setweight(to_tsvector('pg_catalog.english', coalesce(new.description,'')), 'B');
+          return new;
+        end
+        $$ LANGUAGE plpgsql;
+
+        CREATE TRIGGER tsvectorupdate BEFORE INSERT OR UPDATE ON products FOR EACH ROW EXECUTE PROCEDURE products_tsv_trigger();
+        SQL
+      end
+  end
+
+  def self.down
+    say_with_time("Removing trigger to update the tsv column") do
+      execute <<-SQL
+        DROP TRIGGER tsvectorupdate
+        ON products
+        SQL
+    end
+
+    remove_index :products, :tsv
+    remove_column :products, :tsv
+  end
+end

example/db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2019_03_22_200743) do
+ActiveRecord::Schema.define(version: 2019_04_05_042247) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -36,6 +36,8 @@ ActiveRecord::Schema.define(version: 2019_03_22_200743) do
     t.bigint "user_id"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.tsvector "tsv"
+    t.index ["tsv"], name: "index_products_on_tsv", using: :gin
     t.index ["user_id"], name: "index_products_on_user_id"
   end
 

go.mod

@@ -13,5 +13,6 @@ require (
 	github.com/sirupsen/logrus v1.4.0
 	github.com/spf13/viper v1.3.1
 	github.com/valyala/fasttemplate v1.0.1
+	golang.org/x/sys v0.0.0-20181205085412-a5c9d58dba9a
 	mellium.im/sasl v0.2.1 // indirect
 )

psql/psql.go

@@ -397,12 +397,28 @@ func (v *selectBlock) renderRelationship(w io.Writer, schema *DBSchema) {
 
 func (v *selectBlock) renderWhere(w io.Writer) error {
 	if v.sel.Where.Op == qcode.OpEqID {
-		col, ok := v.schema.PCols[v.sel.Table]
-		if !ok {
-			return fmt.Errorf("no primary key defined for %s", v.sel.Table)
+		t, err := v.schema.GetTable(v.sel.Table)
+		if err != nil {
+			return err
+		}
+		if len(t.PrimaryCol) == 0 {
+			return fmt.Errorf("no primary key column defined for %s", v.sel.Table)
 		}
 
-		fmt.Fprintf(w, `(("%s") = ('%s'))`, col.Name, v.sel.Where.Val)
+		fmt.Fprintf(w, `(("%s") = ('%s'))`, t.PrimaryCol, v.sel.Where.Val)
+		return nil
+	}
+
+	if v.sel.Where.Op == qcode.OpTsQuery {
+		t, err := v.schema.GetTable(v.sel.Table)
+		if err != nil {
+			return err
+		}
+		if len(t.TSVCol) == 0 {
+			return fmt.Errorf("no tsv column defined for %s", v.sel.Table)
+		}
+
+		fmt.Fprintf(w, `(("%s") @@ to_tsquery('%s'))`, t.TSVCol, v.sel.Where.Val)
 		return nil
 	}
 

psql/psql_test.go

@@ -337,6 +337,26 @@ func fetchByID(t *testing.T) {
 	}
 }
 
+func searchQuery(t *testing.T) {
+	gql := `query {
+		products(search: "Amazing") {
+			id
+			name
+		}
+	}`
+
+	sql := `SELECT json_object_agg('products', products) FROM (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "products_0"."id" AS "id", "products_0"."name" AS "name") AS "sel_0")) AS "products" FROM (SELECT "products"."id", "products"."name" FROM "products" WHERE ((("tsv") @@ to_tsquery('Amazing'))) LIMIT ('20') :: integer) AS "products_0" LIMIT ('20') :: integer) AS "products_0") AS "done_1337";`
+
+	resSQL, err := compileGQLToPSQL(gql)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if resSQL != sql {
+		t.Fatal(errNotExpected)
+	}
+}
+
 func aggFunction(t *testing.T) {
 	gql := `query {
 		products {
@@ -383,6 +403,7 @@ func TestCompileGQL(t *testing.T) {
 	t.Run("withWhereIsNull", withWhereIsNull)
 	t.Run("withWhereMultiOr", withWhereMultiOr)
 	t.Run("fetchByID", fetchByID)
+	t.Run("searchQuery", searchQuery)
 	t.Run("belongsTo", belongsTo)
 	t.Run("oneToMany", oneToMany)
 	t.Run("manyToMany", manyToMany)

psql/tables.go

@@ -18,11 +18,16 @@ type TTKey struct {
 type DBSchema struct {
 	ColMap   map[TCKey]*DBColumn
 	ColIDMap map[int]*DBColumn
-	PCols    map[string]*DBColumn
+	Tables   map[string]*DBTableInfo
 
 	RelMap map[TTKey]*DBRel
 }
 
+type DBTableInfo struct {
+	PrimaryCol string
+	TSVCol     string
+}
+
 type RelType int
 
 const (
@@ -63,7 +68,7 @@ func initSchema() *DBSchema {
 	return &DBSchema{
 		ColMap:   make(map[TCKey]*DBColumn),
 		ColIDMap: make(map[int]*DBColumn),
-		PCols:    make(map[string]*DBColumn),
+		Tables:   make(map[string]*DBTableInfo),
 		RelMap:   make(map[TTKey]*DBRel),
 	}
 }
@@ -71,6 +76,7 @@ func initSchema() *DBSchema {
 func updateSchema(schema *DBSchema, t *DBTable, cols []*DBColumn) {
 	// Current table
 	ct := strings.ToLower(t.Name)
+	schema.Tables[ct] = &DBTableInfo{}
 
 	// Foreign key columns in current table
 	var jcols []*DBColumn
@@ -82,8 +88,11 @@ func updateSchema(schema *DBSchema, t *DBTable, cols []*DBColumn) {
 
 	for _, c := range cols {
 		switch {
+		case c.Type == "tsvector":
+			schema.Tables[ct].TSVCol = c.Name
+
 		case c.PrimaryKey:
-			schema.PCols[ct] = c
+			schema.Tables[ct].PrimaryCol = c.Name
 
 		case len(c.FKeyTable) != 0:
 			if len(c.FKeyColID) == 0 {
@@ -244,3 +253,11 @@ WHERE c.relkind = 'r'::char
 
 	return t, nil
 }
+
+func (s *DBSchema) GetTable(table string) (*DBTableInfo, error) {
+	t, ok := s.Tables[table]
+	if !ok {
+		return nil, fmt.Errorf("table info not found '%s'", table)
+	}
+	return t, nil
+}

qcode/qcode.go

@@ -85,6 +85,7 @@ const (
 	OpHasKeyAll
 	OpIsNull
 	OpEqID
+	OpTsQuery
 )
 
 func (t ExpOp) String() string {
@@ -139,6 +140,8 @@ func (t ExpOp) String() string {
 		v = "op-is-null"
 	case OpEqID:
 		v = "op-eq-id"
+	case OpTsQuery:
+		v = "op-ts-query"
 	}
 	return fmt.Sprintf("<%s>", v)
 }
@@ -341,6 +344,10 @@ func (com *Compiler) compileArgs(sel *Select, args []*Arg) error {
 			if sel.ID == int16(0) {
 				err = com.compileArgID(sel, args[i])
 			}
+		case "search":
+			if sel.ID == int16(0) {
+				err = com.compileArgSearch(sel, args[i])
+			}
 		case "where":
 			err = com.compileArgWhere(sel, args[i])
 		case "orderby", "order_by", "order":
@@ -438,6 +445,25 @@ func (com *Compiler) compileArgID(sel *Select, arg *Arg) error {
 	return nil
 }
 
+func (com *Compiler) compileArgSearch(sel *Select, arg *Arg) error {
+	if sel.Where != nil && sel.Where.Op == OpTsQuery {
+		return nil
+	}
+
+	ex := &Exp{
+		Op:   OpTsQuery,
+		Type: ValStr,
+		Val:  arg.Val.Val,
+	}
+
+	if sel.Where != nil {
+		sel.Where = &Exp{Op: OpAnd, Children: []*Exp{ex, sel.Where}}
+	} else {
+		sel.Where = ex
+	}
+	return nil
+}
+
 func (com *Compiler) compileArgWhere(sel *Select, arg *Arg) error {
 	var err error