Infer types when clients specify a bind argument with OID zero

server/connection_handler.go

@@ -25,6 +25,7 @@ import (
 	"net"
 	"os"
 	"runtime/debug"
+	"slices"
 	"strings"
 	"sync/atomic"
 
@@ -496,7 +497,10 @@ func (h *ConnectionHandler) handleParse(message *pgproto3.Parse) error {
 
 	// A valid Parse message must have ParameterObjectIDs if there are any binding variables.
 	bindVarTypes := message.ParameterOIDs
-	if len(bindVarTypes) == 0 {
+
+	// Clients can specify an OID of zero to indicate that the type should be inferred. If we
+	// see any zero OIDs, we fall back to extracting the bind var types from the plan.
+	if len(bindVarTypes) == 0 || slices.Contains(bindVarTypes, 0) {
 		// NOTE: This is used for Prepared Statement Tests only.
 		bindVarTypes, err = extractBindVarTypes(analyzedPlan)
 		if err != nil {

testing/go/binding_test.go

@@ -0,0 +1,48 @@
+// Copyright 2025 Dolthub, Inc.
+//
+// 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 _go
+
+import (
+	"strconv"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestBindingWithOidZero tests the behavior of binding parameters when the client specifies a zero OID for any of
+// the parameters.
+func TestBindingWithOidZero(t *testing.T) {
+	// Start up a test server
+	ctx, connection, controller := CreateServer(t, "postgres")
+	defer controller.Stop()
+	conn := connection.Default
+
+	// Create a table to insert into
+	_, err := connection.Exec(ctx, "CREATE TABLE my_table (id INT, name varchar(100));")
+	require.NoError(t, err)
+
+	args := [][]byte{
+		[]byte(strconv.Itoa(42)),
+		[]byte("Alice"),
+	}
+	paramOIDs := []uint32{0, 123}
+	paramFormats := []int16{0, 0}
+	sql := "INSERT INTO my_table (id, name) VALUES ($1, $2);"
+
+	// Execute a query with the zero OID and assert that we don't get an error
+	resultReader := conn.PgConn().ExecParams(ctx, sql, args, paramOIDs, paramFormats, nil)
+	result := resultReader.Read()
+	require.NoError(t, result.Err)
+}