Re: Встречайте, ChatGPT - бот который может поддерживать беседу
Добавлено: Вт апр 23, 2024 12:24 pm
To parse a string and extract numbers into variables in PL/SQL, you can still use the `REGEXP_SUBSTR` function within a PL/SQL block. This approach allows you to work directly with variables, perform additional logic if needed, and handle more complex scenarios.
Below is an example PL/SQL block that demonstrates how you might parse your example string `'(123, 0.456)'` to extract the two numbers into PL/SQL variables:
```plsql
DECLARE
-- Declare variables to hold the extracted numbers
v_input_string VARCHAR2(100) := '(123, 0.456)';
v_first_number NUMBER;
v_second_number NUMBER;
BEGIN
-- Extract the first number
v_first_number := TO_NUMBER(TRIM(REGEXP_SUBSTR(v_input_string, '\s*\(\s*([+-]?\d+(\.\d*)?)', 1, 1, NULL, 1)));
-- Extract the second number
v_second_number := TO_NUMBER(TRIM(REGEXP_SUBSTR(v_input_string, ',\s*([+-]?\d+(\.\d*)?)', 1, 1, NULL, 1)));
-- Display the results
DBMS_OUTPUT.PUT_LINE('First Number: ' || v_first_number);
DBMS_OUTPUT.PUT_LINE('Second Number: ' || v_second_number);
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Error parsing string: ' || SQLERRM);
END;
```
In this PL/SQL block:
- We declare variables to store the input string `v_input_string`, and two variables `v_first_number` and `v_second_number` to hold the numeric values extracted from the string.
- We use `REGEXP_SUBSTR` in combination with `TO_NUMBER` and `TRIM` to extract and convert the numbers from the string. The expressions used here for `REGEXP_SUBSTR` are essentially the same as those provided in the SQL example, tailored to extract the first and second numbers individually.
- The extracted numbers are then printed out using `DBMS_OUTPUT.PUT_LINE`.
- An exception handler catches any errors that might occur during the parsing and conversion process, displaying an error message.
This PL/SQL example illustrates a basic approach to parsing a formatted string and can be extended or modified to suit various formatting requirements or to include more complex data validation and error handling as needed.