Merge branch 'manniwood-add-null-oid'

messages.go

@@ -53,12 +53,6 @@ func (s *startupMessage) Bytes() (buf []byte) {
 	return buf
 }
 
-// Oid (Object Identifier Type) is, according to https://www.postgresql.org/docs/current/static/datatype-oid.html,
-// used internally by PostgreSQL as a primary key for various system tables. It is currently implemented
-// as an unsigned four-byte integer. Its definition can be found in src/include/postgres_ext.h
-// in the PostgreSQL sources.
-type Oid uint32
-
 type FieldDescription struct {
 	Name            string
 	Table           Oid

values.go

@@ -383,6 +383,51 @@ func (n NullInt32) Encode(w *WriteBuf, oid Oid) error {
 	return encodeInt32(w, oid, n.Int32)
 }
 
+// Oid (Object Identifier Type) is, according to https://www.postgresql.org/docs/current/static/datatype-oid.html,
+// used internally by PostgreSQL as a primary key for various system tables. It is currently implemented
+// as an unsigned four-byte integer. Its definition can be found in src/include/postgres_ext.h
+// in the PostgreSQL sources.
+type Oid uint32
+
+// NullOid represents a Command Identifier (Oid) that may be null. NullOid implements the
+// Scanner and Encoder interfaces so it may be used both as an argument to
+// Query[Row] and a destination for Scan.
+//
+// If Valid is false then the value is NULL.
+type NullOid struct {
+	Oid   Oid
+	Valid bool // Valid is true if Oid is not NULL
+}
+
+func (n *NullOid) Scan(vr *ValueReader) error {
+	if vr.Type().DataType != OidOid {
+		return SerializationError(fmt.Sprintf("NullOid.Scan cannot decode OID %d", vr.Type().DataType))
+	}
+
+	if vr.Len() == -1 {
+		n.Oid, n.Valid = 0, false
+		return nil
+	}
+	n.Valid = true
+	n.Oid = decodeOid(vr)
+	return vr.Err()
+}
+
+func (n NullOid) FormatCode() int16 { return BinaryFormatCode }
+
+func (n NullOid) Encode(w *WriteBuf, oid Oid) error {
+	if oid != OidOid {
+		return SerializationError(fmt.Sprintf("NullOid.Encode cannot encode into OID %d", oid))
+	}
+
+	if !n.Valid {
+		w.WriteInt32(-1)
+		return nil
+	}
+
+	return encodeOid(w, oid, n.Oid)
+}
+
 // Xid is PostgreSQL's Transaction ID type.
 //
 // In later versions of PostgreSQL, it is the type used for the backend_xid
@@ -406,7 +451,7 @@ type Xid uint32
 // If Valid is false then the value is NULL.
 type NullXid struct {
 	Xid   Xid
-	Valid bool // Valid is true if Int32 is not NULL
+	Valid bool // Valid is true if Xid is not NULL
 }
 
 func (n *NullXid) Scan(vr *ValueReader) error {
@@ -458,7 +503,7 @@ type Cid uint32
 // If Valid is false then the value is NULL.
 type NullCid struct {
 	Cid   Cid
-	Valid bool // Valid is true if Int32 is not NULL
+	Valid bool // Valid is true if Cid is not NULL
 }
 
 func (n *NullCid) Scan(vr *ValueReader) error {
@@ -513,7 +558,7 @@ type Tid struct {
 // If Valid is false then the value is NULL.
 type NullTid struct {
 	Tid   Tid
-	Valid bool // Valid is true if Int32 is not NULL
+	Valid bool // Valid is true if Tid is not NULL
 }
 
 func (n *NullTid) Scan(vr *ValueReader) error {

values_test.go

@@ -551,39 +551,6 @@ func TestInetCidrTranscodeWithJustIP(t *testing.T) {
 	}
 }
 
-func TestOid(t *testing.T) {
-	t.Parallel()
-
-	conn := mustConnect(t, *defaultConnConfig)
-	defer closeConn(t, conn)
-
-	tests := []struct {
-		sql   string
-		value pgx.Oid
-	}{
-		{"select $1::oid", 0},
-		{"select $1::oid", 1},
-		{"select $1::oid", 4294967295},
-	}
-
-	for i, tt := range tests {
-		expected := tt.value
-		var actual pgx.Oid
-
-		err := conn.QueryRow(tt.sql, expected).Scan(&actual)
-		if err != nil {
-			t.Errorf("%d. Unexpected failure: %v (sql -> %v, value -> %v)", i, err, tt.sql, expected)
-			continue
-		}
-
-		if actual != expected {
-			t.Errorf("%d. Expected %v, got %v (sql -> %v)", i, expected, actual, tt.sql)
-		}
-
-		ensureConnValid(t, conn)
-	}
-}
-
 func TestNullX(t *testing.T) {
 	t.Parallel()
 
@@ -595,6 +562,7 @@ func TestNullX(t *testing.T) {
 		i16 pgx.NullInt16
 		i32 pgx.NullInt32
 		c   pgx.NullChar
+		oid pgx.NullOid
 		xid pgx.NullXid
 		cid pgx.NullCid
 		tid pgx.NullTid
@@ -619,6 +587,9 @@ func TestNullX(t *testing.T) {
 		{"select $1::int2", []interface{}{pgx.NullInt16{Int16: 1, Valid: false}}, []interface{}{&actual.i16}, allTypes{i16: pgx.NullInt16{Int16: 0, Valid: false}}},
 		{"select $1::int4", []interface{}{pgx.NullInt32{Int32: 1, Valid: true}}, []interface{}{&actual.i32}, allTypes{i32: pgx.NullInt32{Int32: 1, Valid: true}}},
 		{"select $1::int4", []interface{}{pgx.NullInt32{Int32: 1, Valid: false}}, []interface{}{&actual.i32}, allTypes{i32: pgx.NullInt32{Int32: 0, Valid: false}}},
+		{"select $1::oid", []interface{}{pgx.NullOid{Oid: 1, Valid: true}}, []interface{}{&actual.oid}, allTypes{oid: pgx.NullOid{Oid: 1, Valid: true}}},
+		{"select $1::oid", []interface{}{pgx.NullOid{Oid: 1, Valid: false}}, []interface{}{&actual.oid}, allTypes{oid: pgx.NullOid{Oid: 0, Valid: false}}},
+		{"select $1::oid", []interface{}{pgx.NullOid{Oid: 4294967295, Valid: true}}, []interface{}{&actual.oid}, allTypes{oid: pgx.NullOid{Oid: 4294967295, Valid: true}}},
 		{"select $1::xid", []interface{}{pgx.NullXid{Xid: 1, Valid: true}}, []interface{}{&actual.xid}, allTypes{xid: pgx.NullXid{Xid: 1, Valid: true}}},
 		{"select $1::xid", []interface{}{pgx.NullXid{Xid: 1, Valid: false}}, []interface{}{&actual.xid}, allTypes{xid: pgx.NullXid{Xid: 0, Valid: false}}},
 		{"select $1::xid", []interface{}{pgx.NullXid{Xid: 4294967295, Valid: true}}, []interface{}{&actual.xid}, allTypes{xid: pgx.NullXid{Xid: 4294967295, Valid: true}}},