From c95e45f45e3c02e590d898f7bf20466ec4a3874d Mon Sep 17 00:00:00 2001
From: dogenkigen <mlaskowsk@gmail.com>
Date: Mon, 4 Dec 2023 13:36:45 +0100
Subject: [PATCH] Making locking parameters more intuitive

---
 clause/locking.go      | 22 ++++++++++++++++++----
 clause/locking_test.go | 10 +++++++---
 2 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/clause/locking.go b/clause/locking.go
index 290aac92..53295b85 100644
--- a/clause/locking.go
+++ b/clause/locking.go
@@ -1,9 +1,23 @@
 package clause
 
+type LockingStrength string
+
+const (
+	LockingStrengthUpdate = LockingStrength("UPDATE")
+	LockingStrengthShare  = LockingStrength("SHARE")
+)
+
+type LockingOptions string
+
+const (
+	LockingOptionsSkipLocked = LockingOptions("SKIP LOCKED")
+	LockingOptionsNoWait     = LockingOptions("NOWAIT")
+)
+
 type Locking struct {
-	Strength string
+	Strength LockingStrength
 	Table    Table
-	Options  string
+	Options  LockingOptions
 }
 
 // Name where clause name
@@ -13,7 +27,7 @@ func (locking Locking) Name() string {
 
 // Build build where clause
 func (locking Locking) Build(builder Builder) {
-	builder.WriteString(locking.Strength)
+	builder.WriteString(string(locking.Strength))
 	if locking.Table.Name != "" {
 		builder.WriteString(" OF ")
 		builder.WriteQuoted(locking.Table)
@@ -21,7 +35,7 @@ func (locking Locking) Build(builder Builder) {
 
 	if locking.Options != "" {
 		builder.WriteByte(' ')
-		builder.WriteString(locking.Options)
+		builder.WriteString(string(locking.Options))
 	}
 }
 
diff --git a/clause/locking_test.go b/clause/locking_test.go
index 0e607312..e45c8e7d 100644
--- a/clause/locking_test.go
+++ b/clause/locking_test.go
@@ -14,17 +14,21 @@ func TestLocking(t *testing.T) {
 		Vars    []interface{}
 	}{
 		{
-			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: "UPDATE"}},
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: clause.LockingStrengthUpdate}},
 			"SELECT * FROM `users` FOR UPDATE", nil,
 		},
 		{
-			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: "SHARE", Table: clause.Table{Name: clause.CurrentTable}}},
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: clause.LockingStrengthShare, Table: clause.Table{Name: clause.CurrentTable}}},
 			"SELECT * FROM `users` FOR SHARE OF `users`", nil,
 		},
 		{
-			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: "UPDATE"}, clause.Locking{Strength: "UPDATE", Options: "NOWAIT"}},
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: clause.LockingStrengthUpdate, Options: clause.LockingOptionsNoWait}},
 			"SELECT * FROM `users` FOR UPDATE NOWAIT", nil,
 		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: clause.LockingStrengthUpdate, Options: clause.LockingOptionsSkipLocked}},
+			"SELECT * FROM `users` FOR UPDATE SKIP LOCKED", nil,
+		},
 	}
 
 	for idx, result := range results {