SQL Functions – Page 3 – SQL Tutorial

SQL DATEADD

October 28, 2011September 4, 2011 by admin

The SQL DATEADD() function is used to add or subtract a time interval to a date.

SQL DAY

October 28, 2011August 23, 2011 by admin

The SQL DAY() function is used to get the day (an integer in the range of 1 to 31) from a date expression.

To get the year from a date: SQL YEAR Function.
To get the month from a date: SQL Month Function.
To get the day from a date: SQL Day Function.

SQL MONTH

October 28, 2011August 21, 2011 by admin

The SQL MONTH() function is used to get the month (an integer in the range of 1 to 12) from a date expression.

If you need to get the year from a date, you could use the SQL YEAR Function.

SQL YEAR

October 28, 2011August 19, 2011 by admin

The SQL YEAR() function is used to get the year of a date expression.

To get the year from a date: SQL YEAR Function.
To get the month from a date: SQL Month Function.
To get the day from a date: SQL Day Function.

SQL TRIM

October 28, 2011August 17, 2011 by admin

The SQL TRIM() function is used to remove the leading or trailing spaces of a string. Different databases have different writtings:

SQL Server	LTRIM(), RTRIM()
Oracle	LTRIM(), RTRIM()
MySQL	TRIM(), LTRIM(), RTRIM()

In SQL Server or Oracle it doesn’t have Trim() function, we can combine LTrim() and RTrim():

RTRIM(LTRIM(str))

SQL MID

October 29, 2011August 4, 2011 by admin

The SQL MID() function is used to get part of a string. It’s supported by MySQL, but not by MS SQL Server or Oracle. In SQL Server, Oracle databse, we can use SQL SUBSTRING or SQL SUBSTR instead.

SQL SUM

October 29, 2011July 26, 2011 by admin

The SQL SUM() function is used to get the total of a column or an expression.

SQL GETDATE()

October 29, 2011July 24, 2011 by admin

The SQL GETDATE() is a SQL Server function which will return current SQL Server system date and time. It is similar to SQL NOW() function in mySQL or SELECT SYSDATE FROM DUAL in Oracle.

SQL NOW

October 29, 2011July 19, 2011 by admin

The SQL NOW() function will return current date and time based on server system.

It is supported by MySQL, in MS SQL Server, the function getdate() will do the same thing, and in Oracle we can use SELECT SYSDATE FROM DUAL to get the current date and time.

SQL LOWER, SQL LCASE

October 29, 2011July 6, 2011 by admin

The SQL LOWER, or SQL LCASE function is used to convert a string to lower case. In SQL Server, it uses the LOWER function.