From 64a51dc093ae2b48625a6d5be333d5df9e29b2a9 Mon Sep 17 00:00:00 2001
From: go-jet <zer0.sub@protonmail.com>
Date: Fri, 18 Oct 2019 10:15:08 +0200
Subject: [PATCH] QRM returns qrm.ErrNoRows when scanning into struct
 destination and query result set is empty.

---
 internal/jet/statement.go   | 4 ++--
 qrm/qrm.go                  | 9 ++++++---
 tests/postgres/scan_test.go | 3 +--
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/internal/jet/statement.go b/internal/jet/statement.go
index ab0c655..e4ba41b 100644
--- a/internal/jet/statement.go
+++ b/internal/jet/statement.go
@@ -16,11 +16,11 @@ type Statement interface {
 
 	// Query executes statement over database connection db and stores row result in destination.
 	// Destination can be either pointer to struct or pointer to a slice.
-	// If destination is pointer to struct and query result set is empty, method returns sql.ErrNoRows.
+	// If destination is pointer to struct and query result set is empty, method returns qrm.ErrNoRows.
 	Query(db qrm.DB, destination interface{}) error
 	// QueryContext executes statement with a context over database connection db and stores row result in destination.
 	// Destination can be either pointer to struct or pointer to a slice.
-	// If destination is pointer to struct and query result set is empty, method returns sql.ErrNoRows.
+	// If destination is pointer to struct and query result set is empty, method returns qrm.ErrNoRows.
 	QueryContext(context context.Context, db qrm.DB, destination interface{}) error
 
 	//Exec executes statement over db connection without returning any rows.
diff --git a/qrm/qrm.go b/qrm/qrm.go
index 8f79c57..e7e6406 100644
--- a/qrm/qrm.go
+++ b/qrm/qrm.go
@@ -2,15 +2,18 @@ package qrm
 
 import (
 	"context"
-	"database/sql"
+	"errors"
 	"github.com/go-jet/jet/internal/utils"
 	"reflect"
 )
 
+// ErrNoRows is returned by Query when query result set is empty
+var ErrNoRows = errors.New("qrm: no rows in result set")
+
 // Query executes Query Result Mapping (QRM) of `query` with list of parametrized arguments `arg` over database connection `db`
 // using context `ctx` into destination `destPtr`.
 // Destination can be either pointer to struct or pointer to slice of structs.
-// If destination is pointer to struct and query result set is empty, method returns sql.ErrNoRows.
+// If destination is pointer to struct and query result set is empty, method returns qrm.ErrNoRows.
 func Query(ctx context.Context, db DB, query string, args []interface{}, destPtr interface{}) error {
 
 	utils.MustBeInitializedPtr(db, "jet: db is nil")
@@ -33,7 +36,7 @@ func Query(ctx context.Context, db DB, query string, args []interface{}, destPtr
 		}
 
 		if rowsProcessed == 0 {
-			return sql.ErrNoRows
+			return ErrNoRows
 		}
 
 		// edge case when row result set contains only NULLs.
diff --git a/tests/postgres/scan_test.go b/tests/postgres/scan_test.go
index f42dbd5..11dac96 100644
--- a/tests/postgres/scan_test.go
+++ b/tests/postgres/scan_test.go
@@ -1,7 +1,6 @@
 package postgres
 
 import (
-	"database/sql"
 	"fmt"
 	"github.com/go-jet/jet/internal/testutils"
 	. "github.com/go-jet/jet/postgres"
@@ -704,7 +703,7 @@ func TestStructScanErrNoRows(t *testing.T) {
 
 	err := query.Query(db, &customer)
 
-	assert.Error(t, err, sql.ErrNoRows.Error())
+	assert.Error(t, err, qrm.ErrNoRows.Error())
 }
 
 func TestStructScanAllNull(t *testing.T) {