Update README.md

README.md

@@ -288,3 +288,35 @@ db.Queryable<T>().As("tableName").ToList();
 public int TestId { get; set; }
   ```
 
+ ##  6. Use Tran
+  ```c
+var db = GetInstance();
+//1. no result 
+var result = db.UseTran(() =>
+{
+var beginCount = db.Queryable<Student>().Count();
+db.Ado.ExecuteCommand("delete student");
+var endCount = db.Queryable<Student>().Count();
+throw new Exception("error haha");
+});
+var count = db.Queryable<Student>().Count();
+
+//2 has result 
+var result2 = db.UseTran<List<Student>>(() =>
+{
+return db.Queryable<Student>().ToList();
+});
+
+//3 use try
+try
+{
+db.Ado.BeginTran();
+
+db.Ado.CommitTran();
+}
+catch (Exception)
+{
+db.Ado.RollbackTran();
+throw;
+}
+   ```