Allow nil pointers to structs

fieldmap.go

@@ -124,8 +124,18 @@ func field(key string, v reflect.Value) (reflect.Value, bool) {
 		is = map[string][]int{}
 		buildIndexes(v.Type(), []int{}, is)
 	}
-	if i, found := is[key]; found {
-		return v.FieldByIndex(i), true
+	if idxs, found := is[key]; found {
+		for i, idx := range idxs {
+			v = v.FieldByIndex([]int{idx})
+			if i != len(idxs)-1 {
+				if v.Type().Kind() == reflect.Ptr && v.IsNil() {
+					return reflect.Value{}, false
+				} else {
+					v = reflect.Indirect(v)
+				}
+			}
+		}
+		return v, true
 	}
 	return reflect.Value{}, false
 }

named_test.go

@@ -315,6 +315,7 @@ func TestNamedDefaultArgs(t *testing.T) {
 		Bar: nil,
 	}, tc, "default2")
 }
+
 func TestNamedIn(t *testing.T) {
 	tc := []testCase{
 		{
@@ -483,6 +484,62 @@ func TestMissing(t *testing.T) {
 	}, "struct/missing/ptr")
 }
 
+func TestNullField(t *testing.T) {
+
+	type testStructEmbeded struct {
+		Foo string
+	}
+
+	type testStructEmbed struct {
+		FooEmbed *testStructEmbeded
+		Bar      string
+	}
+	tt := testStructEmbed{
+		Bar: "bazbar",
+	}
+	doTest(t, tt, []testCase{
+		{
+			src:   `INSERT INTO example (::names) VALUES(::values)`,
+			mySQL: `INSERT INTO example (Bar) VALUES(?)`,
+			pgSQL: `INSERT INTO example (Bar) VALUES($1)`,
+			args:  []interface{}{"bazbar"},
+		},
+		{
+			src:   `UPDATE example SET ::name=::value`,
+			mySQL: `UPDATE example SET Bar=?`,
+			pgSQL: `UPDATE example SET Bar=$1`,
+			args:  []interface{}{"bazbar"},
+		},
+		{
+			src:   `SELECT * FROM foo WHERE foo=:Foo`,
+			mySQL: `SELECT * FROM foo WHERE foo=?`,
+			pgSQL: `SELECT * FROM foo WHERE foo=$1`,
+			args:  []interface{}{nil},
+		},
+	}, "struct/null/null")
+	tt.FooEmbed = &testStructEmbeded{Foo: "foobar"}
+	doTest(t, tt, []testCase{
+		{
+			src:   `INSERT INTO example (::names) VALUES(::values)`,
+			mySQL: `INSERT INTO example (Bar, Foo) VALUES(?, ?)`,
+			pgSQL: `INSERT INTO example (Bar, Foo) VALUES($1, $2)`,
+			args:  []interface{}{"bazbar", "foobar"},
+		},
+		{
+			src:   `UPDATE example SET ::name=::value`,
+			mySQL: `UPDATE example SET Bar=?, Foo=?`,
+			pgSQL: `UPDATE example SET Bar=$1, Foo=$2`,
+			args:  []interface{}{"bazbar", "foobar"},
+		},
+		{
+			src:   `SELECT * FROM foo WHERE foo=:Foo AND bar=:Bar`,
+			mySQL: `SELECT * FROM foo WHERE foo=? AND bar=?`,
+			pgSQL: `SELECT * FROM foo WHERE foo=$1 AND bar=$2`,
+			args:  []interface{}{"foobar", "bazbar"},
+		},
+	}, "struct/null/notnull")
+}
+
 func TestErrors(t *testing.T) {
 	_, _, err := Named("{var}", map[string]interface{}{}, Variables("var"))
 	if err == nil {