TEST:Optimistic Lock in BeforeUpdate: PK Condition Placement Affecting DB Plan Efficiency

tests/update_test.go

@@ -931,3 +931,68 @@ func TestUpdateFrom(t *testing.T) {
 		}
 	}
 }
+
+type Hzw struct {
+	Id      int32  `gorm:"column:ID;primarykey"`
+	Type    int32  `gorm:"column:TYPE;primarykey"`
+	Name    string `gorm:"column:NAME;size:100;not null"`
+	Version int32  `gorm:"column:VERSION;default:0"`
+}
+
+func (h *Hzw) BeforeUpdate(tx *gorm.DB) (err error) {
+	cv := h.Version
+	h.Version++
+	nExprs := tx.Statement.BuildCondition("VERSION", cv)
+	newwhere := clause.Where{Exprs: nExprs}
+	tx.Statement.AddClause(newwhere)
+	return nil
+}
+
+func TestUpdateHookOptimisticLock(t *testing.T) {
+	hzw := &Hzw{
+		Id:      1,
+		Type:    2,
+		Name:    "hzw",
+		Version: 0,
+	}
+
+	statement := DB.Session(&gorm.Session{DryRun: true}).Save(hzw).Statement
+	sqlstr := statement.SQL.String()
+
+	// Find the WHERE clause
+	whereIndex := strings.Index(strings.ToUpper(sqlstr), "WHERE")
+	if whereIndex == -1 {
+		t.Errorf("No WHERE clause found in the SQL statement")
+		return
+	}
+	whereClause := sqlstr[whereIndex+len("WHERE"):]
+
+	// Define the expected order of conditions
+	expectedOrder := []string{"ID", "TYPE", "VERSION"}
+
+	// Use regular expression to match column names
+	re := regexp.MustCompile(`\b(?:ID|TYPE|VERSION)\b`)
+	matches := re.FindAllString(whereClause, -1)
+
+	if len(matches) < len(expectedOrder) {
+		t.Errorf("The actual number of WHERE conditions is less than the expected number")
+		return
+	}
+
+	for i, expected := range expectedOrder {
+		if strings.ToUpper(matches[i]) != expected {
+			t.Errorf("The order of WHERE conditions is incorrect. Expected %s at position %d, but got %s", expected, i+1, matches[i])
+			return
+		}
+	}
+
+	vars := statement.Vars
+	cversion := vars[4]
+	vversion := vars[1]
+	if cversion != int32(0) {
+		t.Fatalf("current VERSION should be 0")
+	}
+	if vversion != int32(1) {
+		t.Fatalf("value VERSION should be 1")
+	}
+}