dialect/sql/builder: make sql.In() with empty args fallback to False()

dialect/sql/builder.go

@@ -1535,8 +1535,10 @@ func In(col string, args ...interface{}) *Predicate {
 
 // In appends the `IN` predicate.
 func (p *Predicate) In(col string, args ...interface{}) *Predicate {
+	// if no arguments were provided, append the FALSE constants,
+	// since we can't apply "IN ()". This will make this predicate falsy.
 	if len(args) == 0 {
-		return p
+		return p.False()
 	}
 	return p.Append(func(b *Builder) {
 		b.Ident(col).WriteOp(OpIn)

dialect/sql/builder_test.go

@@ -2004,6 +2004,14 @@ func TestReusePredicates(t *testing.T) {
 			wantQuery: `SELECT * FROM "users" WHERE "a" = $1 OR "b" = $2`,
 			wantArgs:  []interface{}{"a", "b"},
 		},
+		{
+			p: Or(
+				EQ("a", "a"),
+				In("b"),
+			),
+			wantQuery: `SELECT * FROM "users" WHERE "a" = $1 OR FALSE`,
+			wantArgs:  []interface{}{"a"},
+		},
 		{
 			p: And(
 				EQ("active", true),

entc/gen/template/dialect/sql/predicate.tmpl

@@ -18,12 +18,6 @@ in the LICENSE file in the root directory of this source tree.
 	{{- $storage := $.Scope.Storage -}}
 	func(s *sql.Selector) {
 		{{- if $op.Variadic }}
-			// if not arguments were provided, append the FALSE constants,
-			// since we can't apply "IN ()". This will make this predicate falsy.
-			if len({{ $arg }}) == 0 {
-				s.Where(sql.False())
-				return
-			}
 			v := make([]interface{}, len({{ $arg }}))
 			for i := range v {
 				v[i] = {{ $arg }}[i]