What are the methods for extracting substrings in PL/SQL?

8 months ago

William Carter

2 minutes

In PL/SQL, you can utilize the following methods to extract a substring:

The SUBSTR function is used to extract a substring from a string. The syntax is: SUBSTR(string, start_position, length), where string is the original string, start_position is the starting position, and length is the length of the substring to be extracted.
To extract a string, you can use the combination of the INSTR and SUBSTR functions. First, use the INSTR function to determine the position of the substring in the original string, and then use the SUBSTR function to extract the substring. The example code is as follows:

DECLARE
    original_string VARCHAR2(100) := 'Hello, World';
    start_position NUMBER;
    extracted_string VARCHAR2(100);
BEGIN
    start_position := INSTR(original_string, ', ') + 2;
    extracted_string := SUBSTR(original_string, start_position);
    DBMS_OUTPUT.PUT_LINE(extracted_string);
END;

Get a substring from a string using a regular expression.

DECLARE
    original_string VARCHAR2(100) := '123-456-789';
    extracted_string VARCHAR2(100);
BEGIN
    extracted_string := REGEXP_SUBSTR(original_string, '\d{3}-\d{3}-\d{3}');
    DBMS_OUTPUT.PUT_LINE(extracted_string);
END;

These are commonly used methods for truncating strings in PL/SQL, you can choose the appropriate method based on your specific needs.