Adding a new column with the current time as a default value in MySQL?

For this, you can use the DEFAULT CURRENT_TIMESTAMP clause in MySQL. Following is the syntax −

CREATE TABLE yourTableName
(
   yourColumnName1 dataType1,
   yourColumnName timestamp DEFAULT CURRENT_TIMESTAMP
);

Let us first create a table −

mysql> create table DemoTable
   -> (
   -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   -> DueDate timestamp default current_timestamp
   -> );
Query OK, 0 rows affected (0.86 sec)

Now you can insert some records in the table using insert command −

mysql> insert into DemoTable values();
Query OK, 1 row affected (0.16 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

Output

+----+---------------------+
| Id | DueDate             |
+----+---------------------+
| 1  | 2019-06-08 21:35:58 |
+----+---------------------+
1 row in set (0.00 sec)