ignore mysql-specific comment statements

go/vt/sqlparser/analyzer.go

@@ -45,6 +45,7 @@ const (
  StmtUse
  StmtOther
  StmtUnknown
+ StmtComment
 )
 
 // Preview analyzes the beginning of the query using a simpler and faster
@@ -91,6 +92,9 @@ func Preview(sql string) int {
  case "analyze", "describe", "desc", "explain", "repair", "optimize", "truncate":
  return StmtOther
  }
+ if strings.Index(trimmed, "/*!") == 0 {
+ return StmtComment
+ }
  return StmtUnknown
 }
 

go/vt/sqlparser/analyzer_test.go

@@ -66,6 +66,8 @@ func TestPreview(t *testing.T) {
 
  {"/* leading comment */ select ...", StmtSelect},
  {"/* leading comment */ /* leading comment 2 */ select ...", StmtSelect},
+ {"/*! MySQL-specific comment */", StmtComment},
+ {"/*!50708 MySQL-version comment */", StmtComment},
  {"-- leading single line comment \n select ...", StmtSelect},
  {"-- leading single line comment \n -- leading single line comment 2\n select ...", StmtSelect},
 

go/vt/sqlparser/comments.go

@@ -121,6 +121,10 @@ func StripLeadingComments(sql string) string {
  if index <= 1 {
  return sql
  }
+ // don't strip /*! ... */ or /*!50700 ... */
+ if len(sql) > 2 && sql[2] == '!' {
+ return sql
+ }
  sql = sql[index+2:]
  case '-':
  // Single line comment
@@ -140,3 +144,15 @@ func StripLeadingComments(sql string) string {
 func hasCommentPrefix(sql string) bool {
  return len(sql) > 1 && ((sql[0] == '/' && sql[1] == '*') || (sql[0] == '-' && sql[1] == '-'))
 }
+
+// ExtractMysqlComment extracts the version and SQL from a comment-only query
+// such as /*!50708 sql here */
+func ExtractMysqlComment(sql string) (version string, innerSQL string) {
+ sql = sql[3 : len(sql)-2]
+
+ endOfVersionIndex := strings.IndexFunc(sql, func(c rune) bool { return !unicode.IsDigit(c) })
+ version = sql[0:endOfVersionIndex]
+ innerSQL = strings.TrimFunc(sql[endOfVersionIndex:], unicode.IsSpace)
+
+ return version, innerSQL
+}

go/vt/sqlparser/comments_test.go

@@ -128,6 +128,12 @@ func TestStripLeadingComments(t *testing.T) {
  }, {
  input: "/**/",
  outSQL: "",
+ }, {
+ input: "/*!*/",
+ outSQL: "/*!*/",
+ }, {
+ input: "/*!a*/",
+ outSQL: "/*!a*/",
  }, {
  input: "/*b*/ /*a*/",
  outSQL: "",
@@ -167,3 +173,31 @@ a`,
  }
  }
 }
+
+func TestExtractMysqlComment(t *testing.T) {
+ var testCases = []struct {
+ input, outSQL, outVersion string
+ }{{
+ input: "/*!50708SET max_execution_time=5000 */",
+ outSQL: "SET max_execution_time=5000",
+ outVersion: "50708",
+ }, {
+ input: "/*!50708 SET max_execution_time=5000*/",
+ outSQL: "SET max_execution_time=5000",
+ outVersion: "50708",
+ }, {
+ input: "/*! SET max_execution_time=5000*/",
+ outSQL: "SET max_execution_time=5000",
+ outVersion: "",
+ }}
+ for _, testCase := range testCases {
+ gotVersion, gotSQL := ExtractMysqlComment(testCase.input)
+
+ if gotVersion != testCase.outVersion {
+ t.Errorf("test input: '%s', got version\n%+v, want\n%+v", testCase.input, gotVersion, testCase.outVersion)
+ }
+ if gotSQL != testCase.outSQL {
+ t.Errorf("test input: '%s', got SQL\n%+v, want\n%+v", testCase.input, gotSQL, testCase.outSQL)
+ }
+ }
+}

go/vt/vtgate/executor.go

@@ -195,6 +195,8 @@ func (e *Executor) execute(ctx context.Context, safeSession *SafeSession, sql st
  return e.handleUse(ctx, safeSession, sql, bindVars)
  case sqlparser.StmtOther:
  return e.handleOther(ctx, safeSession, sql, bindVars, target, logStats)
+ case sqlparser.StmtComment:
+ return e.handleComment(ctx, safeSession, sql, bindVars, target, logStats)
  }
  return nil, vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "unrecognized statement: %s", sql)
 }
@@ -705,6 +707,13 @@ func (e *Executor) handleOther(ctx context.Context, safeSession *SafeSession, sq
  return result, err
 }
 
+func (e *Executor) handleComment(ctx context.Context, safeSession *SafeSession, sql string, bindVars map[string]*querypb.BindVariable, target querypb.Target, logStats *LogStats) (*sqltypes.Result, error) {
+ _, sql = sqlparser.ExtractMysqlComment(sql)
+
+ // Not sure if this is a good idea.
+ return &sqltypes.Result{}, nil
+}
+
 // StreamExecute executes a streaming query.
 func (e *Executor) StreamExecute(ctx context.Context, method string, safeSession *SafeSession, sql string, bindVars map[string]*querypb.BindVariable, target querypb.Target, callback func(*sqltypes.Result) error) (err error) {
  logStats := NewLogStats(ctx, method, sql, bindVars)

go/vt/vtgate/executor_test.go

@@ -734,6 +734,26 @@ func TestExecutorUse(t *testing.T) {
  }
 }
 
+func TestExecutorComment(t *testing.T) {
+ executor, _, _, _ := createExecutorEnv()
+
+ stmts := []string{
+ "/*! SET max_execution_time=5000*/",
+ "/*!50708 SET max_execution_time=5000*/",
+ }
+ wantResult := &sqltypes.Result{}
+
+ for _, stmt := range stmts {
+ gotResult, err := executor.Execute(context.Background(), "TestExecute", NewSafeSession(&vtgatepb.Session{TargetString: KsTestUnsharded}), stmt, nil)
+ if err != nil {
+ t.Error(err)
+ }
+ if !reflect.DeepEqual(gotResult, wantResult) {
+ t.Errorf("Exec %s: %v, want %v", stmt, gotResult, wantResult)
+ }
+ }
+}
+
 func TestExecutorOther(t *testing.T) {
  executor, sbc1, sbc2, sbclookup := createExecutorEnv()