chain results when server indicates more results are coming

client/resp.go

@@ -222,15 +222,26 @@ func (c *Conn) readResult(binary bool) (*Result, error) {
 		return nil, errors.Trace(err)
 	}
 
+	var result *Result
 	if firstPkgBuf[0] == OK_HEADER {
-		return c.handleOKPacket(firstPkgBuf)
+		result, err = c.handleOKPacket(firstPkgBuf)
 	} else if firstPkgBuf[0] == ERR_HEADER {
-		return nil, c.handleErrorPacket(append([]byte{}, firstPkgBuf...))
+		err = c.handleErrorPacket(append([]byte{}, firstPkgBuf...))
 	} else if firstPkgBuf[0] == LocalInFile_HEADER {
-		return nil, ErrMalformPacket
+		err = ErrMalformPacket
+	} else {
+		result, err = c.readResultset(firstPkgBuf, binary)
+	}
+
+	// if there are more results, chain resultsets of following results to this
+	// result
+	if err == nil && result.Status&SERVER_MORE_RESULTS_EXISTS > 0 {
+		if res, err := c.readResult(binary); err == nil {
+			result.ChainResult(res)
+		}
 	}
 
-	return c.readResultset(firstPkgBuf, binary)
+	return result, err
 }
 
 func (c *Conn) readResultStreaming(binary bool, result *Result, perRowCb SelectPerRowCallback) error {

mysql/result.go

@@ -7,6 +7,8 @@ type Result struct {
 	AffectedRows uint64
 
 	*Resultset
+
+	Next *Result
 }
 
 type Executer interface {
@@ -19,3 +21,23 @@ func (r *Result) Close() {
 		r.Resultset = nil
 	}
 }
+
+func (r *Result) lastChained() (int, *Result) {
+	count := 1
+	var lastRes *Result
+	for lastRes = r; lastRes.Next != nil; lastRes = lastRes.Next {
+		count++
+	}
+
+	return count, lastRes
+}
+
+func (r *Result) ChainResult(cr *Result) {
+	_, lastRes := r.lastChained()
+	lastRes.Next = cr
+}
+
+func (r *Result) Length() int {
+	n, _ := r.lastChained()
+	return n
+}

mysql/result_test.go

@@ -0,0 +1,30 @@
+package mysql
+
+import (
+	"github.com/pingcap/check"
+)
+
+type resultTestSuite struct {
+}
+
+var _ = check.Suite(&resultTestSuite{})
+
+func (t *resultTestSuite) TestLastChained(c *check.C) {
+	r1 := &Result{}
+	n, last := r1.lastChained()
+	c.Assert(last == r1, check.IsTrue)
+	c.Assert(n, check.Equals, 1)
+
+	r2 := &Result{}
+	r1.ChainResult(r2)
+	n, last = r1.lastChained()
+	c.Assert(last == r2, check.IsTrue)
+	c.Assert(n, check.Equals, 2)
+
+	n, last = r2.lastChained()
+	c.Assert(last == r2, check.IsTrue)
+	c.Assert(n, check.Equals, 1)
+
+	c.Assert(r1.Length(), check.Equals, 2)
+	c.Assert(r2.Length(), check.Equals, 1)
+}

server/caching_sha2_cache_test.go

@@ -192,16 +192,16 @@ func (h *testCacheHandler) handleQuery(query string, binary bool) (*mysql.Result
 		if err != nil {
 			return nil, errors.Trace(err)
 		} else {
-			return &mysql.Result{0, 0, 0, r}, nil
+			return &mysql.Result{0, 0, 0, r, nil}, nil
 		}
 	case "insert":
-		return &mysql.Result{0, 1, 0, nil}, nil
+		return &mysql.Result{0, 1, 0, nil, nil}, nil
 	case "delete":
-		return &mysql.Result{0, 0, 1, nil}, nil
+		return &mysql.Result{0, 0, 1, nil, nil}, nil
 	case "update":
-		return &mysql.Result{0, 0, 1, nil}, nil
+		return &mysql.Result{0, 0, 1, nil, nil}, nil
 	case "replace":
-		return &mysql.Result{0, 0, 1, nil}, nil
+		return &mysql.Result{0, 0, 1, nil, nil}, nil
 	default:
 		return nil, fmt.Errorf("invalid query %s", query)
 	}

server/resp.go

@@ -115,6 +115,29 @@ func (c *Conn) writeAuthMoreDataFastAuth() error {
 	return c.WritePacket(data)
 }
 
+func (c *Conn) writeResultsets(r *Result) error {
+	var err error
+	for res := r; res != nil; res = res.Next {
+		if res.Next != nil {
+			c.status |= SERVER_MORE_RESULTS_EXISTS
+		}
+
+		if res.Resultset == nil {
+			err = c.writeOK(res)
+		} else {
+			err = c.writeResultset(res.Resultset)
+		}
+
+		c.status &= ^SERVER_MORE_RESULTS_EXISTS
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func (c *Conn) writeResultset(r *Resultset) error {
 	columnLen := PutLengthEncodedInt(uint64(len(r.Fields)))
 
@@ -183,8 +206,8 @@ func (c *Conn) writeValue(value interface{}) error {
 	case nil:
 		return c.writeOK(nil)
 	case *Result:
-		if v != nil && v.Resultset != nil {
-			return c.writeResultset(v.Resultset)
+		if v != nil {
+			return c.writeResultsets(v)
 		} else {
 			return c.writeOK(v)
 		}

server/server_test.go

@@ -239,16 +239,16 @@ func (h *testHandler) handleQuery(query string, binary bool) (*mysql.Result, err
 		if err != nil {
 			return nil, errors.Trace(err)
 		} else {
-			return &mysql.Result{0, 0, 0, r}, nil
+			return &mysql.Result{0, 0, 0, r, nil}, nil
 		}
 	case "insert":
-		return &mysql.Result{0, 1, 0, nil}, nil
+		return &mysql.Result{0, 1, 0, nil, nil}, nil
 	case "delete":
-		return &mysql.Result{0, 0, 1, nil}, nil
+		return &mysql.Result{0, 0, 1, nil, nil}, nil
 	case "update":
-		return &mysql.Result{0, 0, 1, nil}, nil
+		return &mysql.Result{0, 0, 1, nil, nil}, nil
 	case "replace":
-		return &mysql.Result{0, 0, 1, nil}, nil
+		return &mysql.Result{0, 0, 1, nil, nil}, nil
 	default:
 		return nil, fmt.Errorf("invalid query %s", query)
 	}