insert select on conflict do update support added (#55)

dataset_insert.go

@@ -72,7 +72,7 @@ func (me *Dataset) toInsertSql(o ConflictExpression, rows ...interface{}) (strin
 		}
 		switch rows[0].(type) {
 		case *Dataset:
-			return me.insertFromSql(*rows[0].(*Dataset), me.isPrepared)
+			return me.insertFromSql(*rows[0].(*Dataset), me.isPrepared, o)
 		}
 
 	}
@@ -202,7 +202,7 @@ func (me *Dataset) insertSql(cols ColumnList, values [][]interface{}, prepared b
 }
 
 //Creates an insert statement with values coming from another dataset
-func (me *Dataset) insertFromSql(other Dataset, prepared bool) (string, []interface{}, error) {
+func (me *Dataset) insertFromSql(other Dataset, prepared bool, c ConflictExpression) (string, []interface{}, error) {
 	buf := NewSqlBuilder(prepared)
 	if err := me.adapter.CommonTablesSql(buf, me.clauses.CommonTables); err != nil {
 		return "", nil, err
@@ -217,6 +217,9 @@ func (me *Dataset) insertFromSql(other Dataset, prepared bool) (string, []interf
 	if err := other.selectSqlWriteTo(buf); err != nil {
 		return "", nil, err
 	}
+	if err := me.adapter.OnConflictSql(buf, c); err != nil {
+		return "", nil, err
+	}
 	if me.adapter.SupportsReturn() {
 		if err := me.adapter.ReturningSql(buf, me.clauses.Returning); err != nil {
 			return "", nil, err

dataset_insert_test.go

@@ -647,6 +647,21 @@ func (me *datasetTest) TestInsertConflictSql__OnConflictDoUpdateWhere() {
 	assert.Equal(t, `INSERT INTO "items" ("address", "name") VALUES ('111 Test Addr', 'Test') ON CONFLICT (name) DO UPDATE SET "address"=excluded.address WHERE ("name" = 'Test')`, sql)
 }
 
+func (me *datasetTest) TestInsertConflictSqlWithDataset__OnConflictDoUpdateWhere() {
+	t := me.T()
+	ds1 := From("items")
+	type item struct {
+		Address string `db:"address"`
+		Name    string `db:"name"`
+	}
+
+	ds2 := From("ds2")
+
+	sql, _, err := ds1.ToInsertConflictSql(DoUpdate("name", Record{"address": L("excluded.address")}).Where(I("name").Eq("Test")), ds2)
+	assert.NoError(t, err)
+	assert.Equal(t, `INSERT INTO "items" SELECT * FROM "ds2" ON CONFLICT (name) DO UPDATE SET "address"=excluded.address WHERE ("name" = 'Test')`, sql)
+}
+
 func (me *datasetTest) TestInsertIgnoreSql() {
 	t := me.T()
 	ds1 := From("items")