In MySQL, you cannot directly set a default value of a VARCHAR column as a TIMESTAMP because they are of different data types. However, you can achieve a similar effect by using a trigger to automatically set the VARCHAR column to the current timestamp when a new row is inserted. Here's an example of how you can do this:
1. Create your table with a VARCHAR column to hold the timestamp:
```sql
CREATE TABLE your_table (
id INT AUTO_INCREMENT PRIMARY KEY,
your_column VARCHAR(20),
-- Other columns
);
```
2. Create a trigger that sets the VARCHAR column to the current timestamp when a new row is inserted:
```sql
DELIMITER //
CREATE TRIGGER set_timestamp
BEFORE INSERT ON your_table
FOR EACH ROW
BEGIN
SET NEW.your_column = NOW();
END;
//
DELIMITER ;
```
This trigger will automatically set the value of `your_column` to the current timestamp whenever a new row is inserted into the table.
Please replace `your_table` and `your_column` with your actual table and column names.