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] 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)
 		}