What Is TIMESTAMP

Q

What Is TIMESTAMP? - MySQL FAQs - Introduction to SQL Date and Time Handling

✍: FYIcenter.com

A

A TIMESTAMP data type allows you to record a date and time like DATETIME data type. But it has some interesting features when used on a table column:

The first TIMESTAMP column in a table will be assigned with the current date and time, if it is not listed in an INSERT statement.
The first TIMESTAMP column in a table will be assigned with the current date and time, if it is not listed in an UPDATE statement.
If a TIMESTAMP column is assigned with NULL, the current date and time will be persisted to this column.
You can turn off the default current date and time on INSERT by defining the column with "DEFAULT 0".

The tutorial exercise below provides you 2 equivalent ways to create a TIMESTAMP column:

CREATE TABLE links (lastDate TIMESTAMP);

CREATE TABLE links (lastDate TIMESTAMP 
   DEFAULT CURRENT_TIMESTAMP
   ON UPDATE CURRENT_TIMESTAMP);

2007-05-11, 5140👍, 0💬

How To Calculate the Difference between Two Time Values
How To Calculate the Difference between Two Time Values? - MySQL FAQs - Introduction to SQL Date and Time Handling If you have two time values, and you want to know the time difference between them, you can use the TIMEDIFF(time1, time2) function as shown below: SELECT TIMEDIFF(TIME('19:26:50'), TIM... 2007-05-11, 5483👍, 0💬

How Many Ways to Get the Current Time
How Many Ways to Get the Current Time? - MySQL FAQs - Introduction to SQL Date and Time Handling There are 8 ways to get the current time: SELECT NOW() FROM DUAL; 2006-07-01 10:02:41 SELECT CURRENT_TIME() FROM DUAL; 10:02:58 SELECT SYSDATE() FROM DUAL; 2006-07-01 10:03:21 mysql> SELECT CURRENT_TIMES... 2007-05-11, 5345👍, 0💬

What Are Date and Time Functions
What Are Date and Time Functions? - MySQL FAQs - Introduction to SQL Date and Time Handling MySQL offers a number of functions for date and time values: ADDDATE(date, INTERVAL expr unit) - Adding days to a date. Same as DATE_ADD(). ADDTIME(time1, time2) - Adding two time values together. CURDATE() -... 2007-05-11, 5265👍, 0💬

How To Present a Past Time in Hours, Minutes and Seconds
How To Present a Past Time in Hours, Minutes and Seconds? - MySQL FAQs - Introduction to SQL Date and Time Handling If you want show an article was posted "n hours n minutes and n seconds ago", you can use the TIMEDIFF(NOW(), pastTime) function as shown in the following tutorial exercise: SELECT TIM... 2007-05-11, 5216👍, 0💬

How To Specify Default Values in INSERT Statement
How To Specify Default Values in INSERT Statement? - MySQL FAQs - Understanding SQL INSERT, UPDATE and DELETE Statements If a column is defined with a default value in a table, you can use the key word DEFAULT in the INSERT statement to take the default value for that column. The following tutorial ... 2007-05-11, 5171👍, 0💬

How To Extract a Unit Value from a Date and Time
How To Extract a Unit Value from a Date and Time? - MySQL FAQs - Introduction to SQL Date and Time Handling If you want to extract a specific date or time unit value out of a date or a time, you can use the EXTRACT(unit FROM expression) function. The tutorial exercise below gives you some good examp... 2007-05-11, 5144👍, 0💬

What Is TIMESTAMP
What Is TIMESTAMP? - MySQL FAQs - Introduction to SQL Date and Time Handling A TIMESTAMP data type allows you to record a date and time like DATETIME data type. But it has some interesting features when used on a table column: The first TIMESTAMP column in a table will be assigned with the current d... 2007-05-11, 5141👍, 0💬

How To Insert a New Row into a Table
How To Insert a New Row into a Table? - MySQL FAQs - Understanding SQL INSERT, UPDATE and DELETE Statements To insert a new row into a table, you should use the INSERT INTO statement with values specified for all columns as shown in the following example: mysql> INSERT INTO fyi_links VALUES (101, 'd... 2007-05-11, 5125👍, 0💬

What Are DML Statements
What Are DML Statements? - MySQL FAQs - Understanding SQL INSERT, UPDATE and DELETE Statements DML (Data Manipulation Language) statements are statements to change data values in database tables. The are 3 primary DML statements: INSERT - Inserting new rows into database tables. UPDATE - Updating ex... 2007-05-11, 5116👍, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.