How to get current datetime in SQL

Question

In order to add the current date and time to the lastModifiedTime column. I work with the MySQL database. My inquiries are:

1. Does SQL have a function that is available? or
2. Every database has a different method for this because it depends on the implementation, right?
3. What is the function that MySQL offers?

 

Answer 1

1. Is there a function available in SQL?
Yes, the SQL 92 spec, Oct 97, pg. 171, section 6.16 specifies these functions:

CURRENT_TIME       Time of day at moment of evaluation
CURRENT_DATE       Date at moment of evaluation
CURRENT_TIMESTAMP  Date & Time at moment of evaluation

2. It is implementation depended so each database has its own function for this.

Each database has its own implementations, but if they adhere to the SQL 92 specification, it must implement the three functions mentioned above (but depends on the version of the spec)

3. What is the function available in MySQL?

NOW() returns 2009-08-05 15:13:00  
CURDATE() returns 2009-08-05  
CURTIME() returns 15:13:00  

I hope this helps you.

Answer 2

SELECT  (SYSDATE)

FROM DUAL;