From c9165fe3cafc9a66e2513caae381e6864fa0a15b Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Fri, 18 Sep 2020 21:42:27 +0800
Subject: [PATCH] Don't panic when using unmatched vars in query, close #3488

---
 clause/expression.go      | 4 ++--
 clause/expression_test.go | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/clause/expression.go b/clause/expression.go
index 49924ef7..6a0dde8d 100644
--- a/clause/expression.go
+++ b/clause/expression.go
@@ -31,7 +31,7 @@ func (expr Expr) Build(builder Builder) {
 	)
 
 	for _, v := range []byte(expr.SQL) {
-		if v == '?' {
+		if v == '?' && len(expr.Vars) > idx {
 			if afterParenthesis {
 				if _, ok := expr.Vars[idx].(driver.Valuer); ok {
 					builder.AddVar(builder, expr.Vars[idx])
@@ -122,7 +122,7 @@ func (expr NamedExpr) Build(builder Builder) {
 			}
 
 			builder.WriteByte(v)
-		} else if v == '?' {
+		} else if v == '?' && len(expr.Vars) > idx {
 			builder.AddVar(builder, expr.Vars[idx])
 			idx++
 		} else if inName {
diff --git a/clause/expression_test.go b/clause/expression_test.go
index 53d79c8f..19e30e6c 100644
--- a/clause/expression_test.go
+++ b/clause/expression_test.go
@@ -76,6 +76,10 @@ func TestNamedExpr(t *testing.T) {
 		Vars:         []interface{}{NamedArgument{Name1: "jinzhu", Name2: "jinzhu2"}},
 		Result:       "@@test AND name1 = ? AND name2 = ? AND name3 = ? ?",
 		ExpectedVars: []interface{}{"jinzhu", "jinzhu2", "jinzhu", nil},
+	}, {
+		SQL:    "create table ? (? ?, ? ?)",
+		Vars:   []interface{}{},
+		Result: "create table ? (? ?, ? ?)",
 	}}
 
 	for idx, result := range results {