Fix Open with OpenFromConnPool

stdlib/sql.go

@@ -20,6 +20,15 @@ type Driver struct {
 }
 
 func (d *Driver) Open(name string) (driver.Conn, error) {
+	if d.Pool != nil {
+		conn, err := d.Pool.Acquire()
+		if err != nil {
+			return nil, err
+		}
+
+		return &Conn{conn: conn}, nil
+	}
+
 	connConfig, err := pgx.ParseURI(name)
 	if err != nil {
 		return nil, err

stdlib/sql_test.go

@@ -117,10 +117,18 @@ func TestOpenFromConnPool(t *testing.T) {
 	}
 	defer closeDB(t, db)
 
+	// Can get pgx.ConnPool from driver
 	driver := db.Driver().(*stdlib.Driver)
 	if driver.Pool == nil {
 		t.Fatal("Expected driver opened through OpenFromConnPool to have Pool, but it did not")
 	}
+
+	// Normal sql/database still works
+	var n int64
+	err = db.QueryRow("select 1").Scan(&n)
+	if err != nil {
+		t.Fatalf("db.QueryRow unexpectedly failed: %v", err)
+	}
 }
 
 func TestStmtExec(t *testing.T) {