MySQL：如何在MySQL中选择范围？

Question

I'm developing an online examination system and I want to get a data from the database if the score of the user is in the range set by the admin.

Range is dynamic and set by the admin.

Example:

TABLE FIELDS VALUES:

outcome_id | outcome_range
     1     | 2,5
     2     | 6,10
     3     | 11,15

USER:

If the user got 3 points it will get the data row outcome id 1 from the table because the score is in the range of 2-5.

Answer 1

The second value (the max-points) might be superfluous if
a) the ranges are continuous and
b) you will select exactly 1 (or 0) outcome id

CREATE TABLE outcomes (
  outcome_id int,
  outcome_min int,
  unique index(outcome_min)
)

INSERT INTO outcomes (outcome_id,outcome_min) VALUES
  (1,2),
  (2,6),
  (3,11)

SELECT outcome_id FROM outcomes WHERE outcome_min>=3 ORDER BY outcome_min ASC LIMIT 1

Answer 2

You can separate the range

Table

outcome_id | min_outcome | max_outcome
     1     | 2           | 5
     2     | 6           | 10
     3     | 11          | 15

Query

SELECT * FROM table_name WHERE min_outcome <= 3 AND max_outcome >= 3

Create table

CREATE TABLE IF NOT EXISTS `table_name` (
  `outcome_id` int(11) NOT NULL AUTO_INCREMENT,
  `min_outcome` int(10) NOT NULL,
  `max_outcome` int(10) NOT NULL,
  PRIMARY KEY (`outcome_id`)
) ;

INSERT INTO `table_name` (`outcome_id`, `min_outcome`, `max_outcome`) VALUES
(1, 2, 5),
(2, 6, 10),
(3, 11, 15);

Answer 3

You not need to change your table structure.

just use SUBSTRING_INDEX mysql function to find the values as min and max value.

SELECT `outcome_id`, `outcome_range` FROM `test` HAVING SUBSTRING_INDEX(`outcome_range`, ',', 1) <= 3 AND SUBSTRING_INDEX(`outcome_range`, ',', -1) >= 3

This Pretty thing also done by using the WHERE clause. The same result come out.

SELECT `outcome_id`, `outcome_range` FROM `test` WHERE SUBSTRING_INDEX(`outcome_range`, ',', 1) <= 3 AND SUBSTRING_INDEX(`outcome_range`, ',', -1) >= 3

Here i use 3 as static value. you can use the dynamic one. This is a user input.

Output:

 outcome_id outcome_range 1 2,5