From 6da7e284f16d6a02aef3d16100160f61bc945f9c Mon Sep 17 00:00:00 2001
From: Vivek Menezes <vivek.menezes@gmail.com>
Date: Tue, 4 Apr 2017 18:09:57 -0400
Subject: [PATCH] sql: ensure a Prepare referencing a table created in the same
 txn works

fixes #14548
---
 pkg/sql/executor.go           | 12 ++++++------
 pkg/sql/pgwire/pgwire_test.go | 36 +++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/pkg/sql/executor.go b/pkg/sql/executor.go
index e364be2a6caa..9a1d345cfff6 100644
--- a/pkg/sql/executor.go
+++ b/pkg/sql/executor.go
@@ -446,12 +446,12 @@ func (e *Executor) Prepare(
 
 	// Prepare needs a transaction because it needs to retrieve db/table
 	// descriptors for type checking.
-	// TODO(andrei): is this OK? If we're preparing as part of a SQL txn, how do
-	// we check that they're reading descriptors consistent with the txn in which
-	// they'll be used?
-	txn := client.NewTxn(e.cfg.DB)
-	if err := txn.SetIsolation(session.DefaultIsolationLevel); err != nil {
-		panic(err)
+	txn := session.TxnState.txn
+	if txn == nil {
+		txn = client.NewTxn(e.cfg.DB)
+		if err := txn.SetIsolation(session.DefaultIsolationLevel); err != nil {
+			panic(err)
+		}
 	}
 	txn.Proto().OrigTimestamp = e.cfg.Clock.Now()
 
diff --git a/pkg/sql/pgwire/pgwire_test.go b/pkg/sql/pgwire/pgwire_test.go
index 6299ff6aa949..a94879cd13a0 100644
--- a/pkg/sql/pgwire/pgwire_test.go
+++ b/pkg/sql/pgwire/pgwire_test.go
@@ -434,6 +434,42 @@ func TestPGPrepareFail(t *testing.T) {
 	}
 }
 
+// Run a Prepare referencing a table created in the same transaction.
+func TestPGPrepareAfterCreateInTxn(t *testing.T) {
+	defer leaktest.AfterTest(t)()
+	s, _, _ := serverutils.StartServer(t, base.TestServerArgs{})
+	defer s.Stopper().Stop()
+
+	pgURL, cleanupFn := sqlutils.PGUrl(t, s.ServingAddr(), "TestPGPrepareAfterCreateInTxn", url.User(security.RootUser))
+	defer cleanupFn()
+
+	db, err := gosql.Open("postgres", pgURL.String())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	tx, err := db.Begin()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if _, err := tx.Exec(`
+	CREATE DATABASE d;
+	CREATE TABLE d.kv (k CHAR PRIMARY KEY, v CHAR);
+`); err != nil {
+		t.Fatal(err)
+	}
+
+	if _, err := tx.Prepare(`INSERT INTO d.kv (k,v) VALUES ($1, $2);`); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := tx.Commit(); err != nil {
+		t.Fatal(err)
+	}
+}
+
 type preparedQueryTest struct {
 	qargs   []interface{}
 	results [][]interface{}