From dc3f2394b72a13c94faa0893f155ac4893ee85df Mon Sep 17 00:00:00 2001
From: sirius <916108538@qq.com>
Date: Thu, 17 Apr 2025 11:43:14 +0800
Subject: [PATCH 1/2] FIX:Optimistic Lock in BeforeUpdate: PK Condition
 Placement Affecting DB Plan Efficiency

---
 callbacks/update.go | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/callbacks/update.go b/callbacks/update.go
index 7cde7f61..be18e181 100644
--- a/callbacks/update.go
+++ b/callbacks/update.go
@@ -259,6 +259,7 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 		switch updatingValue.Kind() {
 		case reflect.Struct:
 			set = make([]clause.Assignment, 0, len(stmt.Schema.FieldsByDBName))
+			priExpr := make([]clause.Expression, 0)
 			for _, dbName := range stmt.Schema.DBNames {
 				if field := updatingSchema.LookUpField(dbName); field != nil {
 					if !field.PrimaryKey || !updatingValue.CanAddr() || stmt.Dest != stmt.Model {
@@ -290,11 +291,26 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 						}
 					} else {
 						if value, isZero := field.ValueOf(stmt.Context, updatingValue); !isZero {
-							stmt.AddClause(clause.Where{Exprs: []clause.Expression{clause.Eq{Column: field.DBName, Value: value}}})
+							// stmt.AddClause(clause.Where{Exprs: []clause.Expression{clause.Eq{Column: field.DBName, Value: value}}})
+							priExpr = append(priExpr, clause.Eq{Column: field.DBName, Value: value})
+
 						}
 					}
 				}
 			}
+			if len(priExpr) > 0 {
+				where := clause.Where{Exprs: priExpr}
+				wname := where.Name()
+				existWc := stmt.Clauses[wname]
+				existWc.Name = wname
+				if existingWhere, ok := existWc.Expression.(clause.Where); ok {
+					where.Exprs = append(priExpr, existingWhere.Exprs...)
+					existWc.Expression = where
+					stmt.Clauses[wname] = existWc
+				}
+				existWc.Expression = where
+				stmt.Clauses[wname] = existWc
+			}
 		default:
 			stmt.AddError(gorm.ErrInvalidData)
 		}

From ff8d0b3ddb2b1edfab014e0efa7cfa342515ea5d Mon Sep 17 00:00:00 2001
From: sirius <916108538@qq.com>
Date: Thu, 17 Apr 2025 15:05:25 +0800
Subject: [PATCH 2/2] TEST:Optimistic Lock in BeforeUpdate: PK Condition
 Placement Affecting DB Plan Efficiency

---
 tests/update_test.go | 65 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/tests/update_test.go b/tests/update_test.go
index 9eb9dbfc..a767b99d 100644
--- a/tests/update_test.go
+++ b/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")
+	}
+}