mysql by order by case when cast() - mysql

Question

I need to sort the ID field, but the id field is dynamic, I need to judge before sorting, if it is a pure number, then I convert it to a numeric type and then sort. But I have some problems in order by case when cast(),can somebody help me?
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for BASIS_EXP_ORG
-- ----------------------------
DROP TABLE IF EXISTS `BASIS_EXP_ORG`;
CREATE TABLE `BASIS_EXP_ORG` (
`NAME` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT 'name',
`ORG_ID` varchar(8) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL DEFAULT '' COMMENT 'org',
PRIMARY KEY (`ORG_ID`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = latin1 COLLATE = latin1_swedish_ci ROW_FORMAT = Compact;
-- ----------------------------
-- Records of BASIS_EXP_ORG
-- ----------------------------
INSERT INTO `BASIS_EXP_ORG` VALUES ('OU_2', '101');
INSERT INTO `BASIS_EXP_ORG` VALUES ('INV_2', '141');
INSERT INTO `BASIS_EXP_ORG` VALUES ('OU_1', '85');
SET FOREIGN_KEY_CHECKS = 1;
----------------------------------------------------------------
select distinct ORG_ID as id,
NAME as text
from BASIS_EXP_ORG
where 1 = 1
and ORG_ID in (101,141,85)
order by
case when ORG_ID REGEXP '(^[0-9])'
then ORG_ID +0
ELSE ORG_ID END
asc

Answer 1

Is this what you want?
I think you just need to place (ORG_ID + 0) at the order by phase to cast it to numeric type.
Please try this.
select distinct ORG_ID,
NAME as text
from BASIS_EXP_ORG
where 1 = 1
and ORG_ID in (101,141,85)
order by (ORG_ID + 0) DESC

Answer 2

If you're using MySQL version 8+ and MariaDB 10+, you can use REGEXP_REPLACE to remove strings then CAST it:
SELECT DISTINCT ORG_ID AS id,CAST(REGEXP_REPLACE(ORG_ID,'[a-zA-Z]','') AS SIGNED),
NAME AS TEXT
FROM BASIS_EXP_ORG
WHERE 1 = 1
ORDER BY CAST(REGEXP_REPLACE(ORG_ID,'[a-zA-Z]','') AS SIGNED) ASC;
Check demo here: https://www.db-fiddle.com/f/itK8PM7WjURn5Jaynurz4N/0
I added a few row data in the fiddle and remove the and ORG_ID in (101,141,85) in WHERE condition for testing purpose.
EDIT:
This query below should be able to get it working on older MySQL:
SELECT DISTINCT ORG_ID AS id,SUBSTRING(ORG_ID,
LEAST(
IF(LOCATE(1,org_id)=0,99,LOCATE(1,org_id)),
IF(LOCATE(2,org_id)=0,99,LOCATE(2,org_id)),
IF(LOCATE(3,org_id)=0,99,LOCATE(3,org_id)),
IF(LOCATE(4,org_id)=0,99,LOCATE(4,org_id)),
IF(LOCATE(5,org_id)=0,99,LOCATE(5,org_id)),
IF(LOCATE(6,org_id)=0,99,LOCATE(6,org_id)),
IF(LOCATE(7,org_id)=0,99,LOCATE(7,org_id)),
IF(LOCATE(8,org_id)=0,99,LOCATE(8,org_id)),
IF(LOCATE(9,org_id)=0,99,LOCATE(9,org_id))),99)+0 AS num,
NAME AS TEXT
FROM BASIS_EXP_ORG
WHERE 1 = 1
ORDER BY num ASC;
Demo on MySQL 5.7: https://www.db-fiddle.com/f/itK8PM7WjURn5Jaynurz4N/3
As you can see, I'm using a series of functions to remove the strings from the original data. First I use LOCATE to find numbers range from 1-9 and their location. The following query and result can help to clarify more:
SELECT *,
LOCATE(1,org_id),
LOCATE(2,org_id),
LOCATE(3,org_id),
LOCATE(4,org_id),
LOCATE(5,org_id),
LOCATE(6,org_id),
LOCATE(7,org_id),
LOCATE(8,org_id),
LOCATE(9,org_id) FROM BASIS_EXP_ORG;
+-------+----------+------------+------------+------------+------------+------------+------------+------------+------------+------------+
| NAME | ORG_ID | LOCATE | LOCATE | LOCATE | LOCATE | LOCATE | LOCATE | LOCATE | LOCATE | LOCATE |
| | | (1,org_id) | (2,org_id) | (3,org_id) | (4,org_id) | (5,org_id) | (6,org_id) | (7,org_id) | (8,org_id) | (9,org_id) |
+-------+----------+------------+------------+------------+------------+------------+------------+------------+------------+------------+
| OU_1 | 00000001 | 8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| OU_2 | 101 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| INV_2 | 141 | 1 | 0 | 0 | 2 | 0 | 0 | 0 | 0 | 0 |
| OU_3 | 81 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
| OU_1 | 85 | 0 | 0 | 0 | 0 | 2 | 0 | 0 | 1 | 0 |
| INV_2 | a101 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| OU_1 | b40 | 0 | 0 | 0 | 2 | 0 | 0 | 0 | 0 | 0 |
| OU_1 | c0001 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| OU_2 | c101 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
+-------+----------+------------+------------+------------+------------+------------+------------+------------+------------+------------+
The logic behind this is to know where is the location of the number stated in LOCATE (if any). Then if it returns 0 (meaning the number doesn't exists), give it 99 so when the LEAST happen, it won't see zeros. The main reason of using LEAST however is to get the first number found instead of the smallest number found. That being said, refer to the example above and look for the data with ORG_ID=81. (LOCATE(1,org_id) found number 1 in location 2 while (LOCATE(8,org_id) found the number 8 in location 1. If we took the smallest number to judge, then we will get number 1 instead of 81 in the SUBSTRING function (this took me a while to figure out ;P). Then we use them all in the SUBSTRING and we add +0 at the last value retrieved.
tl;dr > if we convert this into plain query, we will get basically something like this:
SELECT DISTINCT ORG_ID AS id, SUBSTRING(ORG_ID,**8**,99)+0 as num
FROM BASIS_EXP_ORG
WHERE 1 = 1
AND ORG_ID='00000001'
ORDER BY num ASC;
To obtain the **8** is where all the process happen.