Fix 39 (#41)

* fix 39

* update instance_test

connection.go

@@ -41,6 +41,8 @@ func (*odpsConn) Close() error {
 
 // Implements database/sql/driver.Execer. Notice result is nil
 func (conn *odpsConn) Exec(query string, args []driver.Value) (driver.Result, error) {
+	log.Debug("--------------------------------------------------------------------------------")
+	log.Debugf("Exec:[%s]", query)
 	ins, err := conn.wait(query, args)
 	if err != nil {
 		return nil, err

connection_test.go

@@ -2,6 +2,8 @@ package gomaxcompute
 
 import (
 	"database/sql"
+	"fmt"
+	"math/rand"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -22,6 +24,18 @@ func TestQuery(t *testing.T) {
 	}
 }
 
+func TestExec(t *testing.T) {
+	a := assert.New(t)
+	db, err := sql.Open("maxcompute", cfg4test.FormatDSN())
+	a.NoError(err)
+
+	tn := fmt.Sprintf("unitest%d", rand.Int())
+	_, err = db.Exec(fmt.Sprintf("CREATE TABLE IF NOT EXISTS %s(shop_name STRING);", tn))
+	a.NoError(err)
+	_, err = db.Exec(fmt.Sprintf("DROP TABLE %s;", tn))
+	a.NoError(err)
+}
+
 func TestQueryBase64(t *testing.T) {
 	a := assert.New(t)
 	db, err := sql.Open("maxcompute", cfg4test.FormatDSN())

instance.go

@@ -95,6 +95,14 @@ func decodeInstanceResult(result []byte) (string, error) {
 	if err := xml.Unmarshal(result, &ir); err != nil {
 		return "", err
 	}
+
+	if ir.Result.Format == "text" {
+		// FIXME(tony): the result non-query statement usually in text format.
+		// Go's database/sql API only supports lastId and affectedRows.
+		log.Debug(ir.Result.Content)
+		return "", nil
+	}
+
 	if ir.Result.Format != "csv" {
 		return "", errors.WithStack(fmt.Errorf("unsupported format %v", ir.Result.Format))
 	}

instance_test.go

@@ -37,7 +37,7 @@ func TestDecodeInstanceResult(t *testing.T) {
 
 	{
 		_, err := decodeInstanceResult([]byte(fmt.Sprintf(s, "", "Format=\"text\"", "1,2,3")))
-		a.Error(err) // unsupported format text
+		a.NoError(err)
 	}
 
 	{