From b99ce66f408d824410761df51b945521b5016dad Mon Sep 17 00:00:00 2001
From: Ariel Mashraki <7413593+a8m@users.noreply.github.com>
Date: Thu, 25 Nov 2021 12:03:12 +0200
Subject: [PATCH] dialect/sql: calling Update.Add after Update.Set should
 append expression (#2168)

---
 dialect/sql/builder.go      |  7 +++++--
 dialect/sql/builder_test.go | 16 ++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/dialect/sql/builder.go b/dialect/sql/builder.go
index e0fafe2e7..68667e7dd 100644
--- a/dialect/sql/builder.go
+++ b/dialect/sql/builder.go
@@ -1079,9 +1079,11 @@ func (u *UpdateBuilder) Set(column string, v interface{}) *UpdateBuilder {
 	return u
 }
 
-// Add adds a numeric value to the given column.
+// Add adds a numeric value to the given column. Note that, calling Set(c)
+// after Add(c) will erase previous calls with c from the builder.
 func (u *UpdateBuilder) Add(column string, v interface{}) *UpdateBuilder {
-	return u.Set(column, ExprFunc(func(b *Builder) {
+	u.columns = append(u.columns, column)
+	u.values = append(u.values, ExprFunc(func(b *Builder) {
 		b.WriteString("COALESCE")
 		b.Nested(func(b *Builder) {
 			b.Ident(Table(u.table).C(column)).Comma().WriteByte('0')
@@ -1089,6 +1091,7 @@ func (u *UpdateBuilder) Add(column string, v interface{}) *UpdateBuilder {
 		b.WriteString(" + ")
 		b.Arg(v)
 	}))
+	return u
 }
 
 // SetNull sets a column as null value.
diff --git a/dialect/sql/builder_test.go b/dialect/sql/builder_test.go
index be252ec84..fd328c792 100644
--- a/dialect/sql/builder_test.go
+++ b/dialect/sql/builder_test.go
@@ -457,6 +457,22 @@ func TestBuilder(t *testing.T) {
 			wantQuery: "UPDATE `users` SET `age` = COALESCE(`users`.`age`, 0) + ? WHERE `nickname` LIKE ?",
 			wantArgs:  []interface{}{1, "a8m%"},
 		},
+		{
+			input: Update("users").
+				Set("age", 1).
+				Add("age", 2).
+				Where(HasPrefix("nickname", "a8m")),
+			wantQuery: "UPDATE `users` SET `age` = ?, `age` = COALESCE(`users`.`age`, 0) + ? WHERE `nickname` LIKE ?",
+			wantArgs:  []interface{}{1, 2, "a8m%"},
+		},
+		{
+			input: Update("users").
+				Add("age", 2).
+				Set("age", 1).
+				Where(HasPrefix("nickname", "a8m")),
+			wantQuery: "UPDATE `users` SET `age` = ? WHERE `nickname` LIKE ?",
+			wantArgs:  []interface{}{1, "a8m%"},
+		},
 		{
 			input: Dialect(dialect.Postgres).
 				Update("users").