Make StatementType a type alias instead of an int

Signed-off-by: Andres Taylor <antaylor@squareup.com>

go/trace/trace.go

@@ -66,7 +66,7 @@ func NewFromString(inCtx context.Context, parent, label string) (Span, context.C
 // AnnotateSQL annotates information about a sql query in the span. This is done in a way
 // so as to not leak personally identifying information (PII), or sensitive personal information (SPI)
 func AnnotateSQL(span Span, sql string) {
-	span.Annotate("sql-statement-type", sqlparser.StmtType(sqlparser.Preview(sql)))
+	span.Annotate("sql-statement-type", sqlparser.Preview(sql).String())
 }
 
 // FromContext returns the Span from a Context if present. The bool return

go/vt/sqlparser/analyzer.go

@@ -30,10 +30,13 @@ import (
 	vtrpcpb "vitess.io/vitess/go/vt/proto/vtrpc"
 )
 
+// StatementType encodes the type of a SQL statement
+type StatementType int
+
 // These constants are used to identify the SQL statement type.
 // Changing this list will require reviewing all calls to Preview.
 const (
-	StmtSelect = iota
+	StmtSelect StatementType = iota
 	StmtStream
 	StmtInsert
 	StmtReplace
@@ -53,7 +56,7 @@ const (
 
 // Preview analyzes the beginning of the query using a simpler and faster
 // textual comparison to identify the statement type.
-func Preview(sql string) int {
+func Preview(sql string) StatementType {
 	trimmed := StripLeadingComments(sql)
 
 	if strings.Index(trimmed, "/*!") == 0 {
@@ -111,9 +114,8 @@ func Preview(sql string) int {
 	return StmtUnknown
 }
 
-// StmtType returns the statement type as a string
-func StmtType(stmtType int) string {
-	switch stmtType {
+func (s StatementType) String() string {
+	switch s {
 	case StmtSelect:
 		return "SELECT"
 	case StmtStream:

go/vt/sqlparser/analyzer_test.go

@@ -27,7 +27,7 @@ import (
 func TestPreview(t *testing.T) {
 	testcases := []struct {
 		sql  string
-		want int
+		want StatementType
 	}{
 		{"select ...", StmtSelect},
 		{"    select ...", StmtSelect},

go/vt/vtgate/executor.go

@@ -167,7 +167,7 @@ func (e *Executor) execute(ctx context.Context, safeSession *SafeSession, sql st
 	}
 
 	stmtType := sqlparser.Preview(sql)
-	logStats.StmtType = sqlparser.StmtType(stmtType)
+	logStats.StmtType = stmtType.String()
 
 	// Mysql warnings are scoped to the current session, but are
 	// cleared when a "non-diagnostic statement" is executed:
@@ -1126,7 +1126,7 @@ func (e *Executor) handleComment(sql string) (*sqltypes.Result, error) {
 // 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)
-	logStats.StmtType = sqlparser.StmtType(sqlparser.Preview(sql))
+	logStats.StmtType = sqlparser.Preview(sql).String()
 	defer logStats.Send()
 
 	if bindVars == nil {
@@ -1137,7 +1137,7 @@ func (e *Executor) StreamExecute(ctx context.Context, method string, safeSession
 
 	// check if this is a stream statement for messaging
 	// TODO: support keyRange syntax
-	if logStats.StmtType == sqlparser.StmtType(sqlparser.StmtStream) {
+	if logStats.StmtType == sqlparser.StmtStream.String() {
 		return e.handleMessageStream(ctx, safeSession, sql, target, callback, vcursor, logStats)
 	}
 
@@ -1521,7 +1521,7 @@ func (e *Executor) prepare(ctx context.Context, safeSession *SafeSession, sql st
 	}
 
 	stmtType := sqlparser.Preview(sql)
-	logStats.StmtType = sqlparser.StmtType(stmtType)
+	logStats.StmtType = stmtType.String()
 
 	// Mysql warnings are scoped to the current session, but are
 	// cleared when a "non-diagnostic statement" is executed:

go/vt/vttablet/tabletserver/vstreamer/vstreamer.go

@@ -325,7 +325,7 @@ func (vs *vstreamer) parseEvent(ev mysql.BinlogEvent) ([]*binlogdatapb.VEvent, e
 		case sqlparser.StmtOther:
 			// These are DBA statements like REPAIR that can be ignored.
 		default:
-			return nil, fmt.Errorf("unexpected statement type %s in row-based replication: %q", sqlparser.StmtType(cat), q.SQL)
+			return nil, fmt.Errorf("unexpected statement type %s in row-based replication: %q", cat, q.SQL)
 		}
 	case ev.IsTableMap():
 		// This is very frequent. It precedes every row event.