How to take last four characters from a varchar?

问题:

I'm trying to take the last four characters only from a varchar field. All the rows are different lengths. What function should I be using to accomplish this?

回答1:

Right should do:

select RIGHT('abcdeffff',4)

回答2:

SUBSTR(column, LENGTH(column) - 4, 4)

LENGTH returns length of string and SUBSTR returns 4 characters from "the position length - 4"

回答3:

Use the RIGHT() function: http://msdn.microsoft.com/en-us/library/ms177532(v=sql.105).aspx

SELECT RIGHT( '1234567890', 4 ); -- returns '7890'

回答4:

RIGHT ( character_expression , integer_expression )

SELECT RIGHT(column, 4) FROM ...

Also a list of other string functions.

回答5:

For Oracle SQL, SUBSTR(column_name, -# of characters requested) will extract last three characters for a given query. e.g.

SELECT SUBSTR(description,-3) FROM student.course;