Add conn session vars (pingcap#265)

dumpling/v4/export/sql.go

@@ -514,8 +514,20 @@ func isUnknownSystemVariableErr(err error) bool {
 func resetDBWithSessionParams(tctx *tcontext.Context, db *sql.DB, dsn string, params map[string]interface{}) (*sql.DB, error) {
 	support := make(map[string]interface{})
 	for k, v := range params {
+		var pv interface{}
+		if str, ok := v.(string); ok {
+			if pvi, err := strconv.ParseInt(str, 10, 64); err == nil {
+				pv = pvi
+			} else if pvf, err := strconv.ParseFloat(str, 64); err == nil {
+				pv = pvf
+			} else {
+				pv = str
+			}
+		} else {
+			pv = v
+		}
 		s := fmt.Sprintf("SET SESSION %s = ?", k)
-		_, err := db.ExecContext(tctx, s, v)
+		_, err := db.ExecContext(tctx, s, pv)
 		if err != nil {
 			if isUnknownSystemVariableErr(err) {
 				tctx.L().Info("session variable is not supported by db", zap.String("variable", k), zap.Reflect("value", v))
@@ -524,7 +536,7 @@ func resetDBWithSessionParams(tctx *tcontext.Context, db *sql.DB, dsn string, pa
 			return nil, errors.Trace(err)
 		}
 
-		support[k] = v
+		support[k] = pv
 	}
 
 	for k, v := range support {