Oracle function substr (str1, pos, [len])

Obtain the substring function. Optional. If there is no len, the substring from the returned position to the end of the substring is unknown. Here, a pos can be specified as a negative number, and the position is from the word

Obtain the substring function. Optional. If there is no len, the substring from the returned position to the end of the substring is unknown. Here, a pos can be specified as a negative number, and the position is from the word

Obtain the substring function. The parameter is optional. If there is no len, the substring from the returned position to the end of the substring is unknown.

Here, you can specify pos as a negative number, starting from the position of pos characters before the end of the string.

For example:

Select substr ('abcdefg',-1) from dual;
The returned result is g.

Select substr ('abcdefg',-3, 2) from dual;
Returned result: ef