How to use regex in mysql query to remove specific characters? - mysql

Question

In my query I am using REPLACE( b.DESCRIPTION,'SP. Z O.O.','') AS DESCRIPTION to remove SP. Z O.O. these characters from columns. And hopefully it's working for me. But in my database SP. Z O.O. this characters are stored in different ways. Like sp. Z.o.o, SP. z.o.o etc.
Somewhere it's stored in capital letters and somewhere it's stored in small letters.
REPLACE( b.DESCRIPTION,'SP. Z O.O.','') AS DESCRIPTION by this method I am only able to remove capital letters. I want all conditions to remove similar words like this.
How to apply regex or case in this situation?
This is my query:
SELECT b.TRANS_DETAILS_ID, b.CREDIT_AMOUNT, b.ENTITY_NAME, REPLACE( b.DESCRIPTION,'SP. Z O.O.','') AS DESCRIPTION, DATE_FORMAT(a.TRANSACTION_DATE_TIME,'%d-%m-%Y') AS TRANS_DATE FROM bank_book_transaction_master a, bank_book_transaction_details b WHERE a.TRANSACTION_DATE_TIME BETWEEN '2017-12-01' AND '2017-12-26' AND DEBIT_CREDIT_FLAG = 1 AND a.ORG_ID = '53' AND a.BANK_ID = '14' AND a.TRANSACTION_ID = b.TRANS_MASTER_ID

Answer 1

You can do it with a query like this:
UPDATE strtest
SET mystring = CONCAT(
LEFT (mystring, POSITION('SP. Z O.O.' IN mystring)-1),
RIGHT(mystring, LENGTH(mystring)-POSITION('SP. Z O.O.' IN mystring)-9)
)
WHERE mystring LIKE '%SP. Z O.O.%';
Sample:
Test Table
MariaDB [bernd]> SELECT * from strtest;
+----+------------------+
| id | mystring |
+----+------------------+
| 1 | SP. Z O.O. |
| 2 | ABCSP. Z O.O. |
| 3 | SP. Z O.O.XYZ |
| 4 | QWESP. Z O.O.IOP |
| 5 | AAASp. Z o.O.LLL |
+----+------------------+
5 rows in set (0.00 sec)
Remove the String in a SELECT ( The >>><<< are only for test)
MariaDB [bernd]> SELECT CONCAT( '>>>',
-> LEFT (mystring, POSITION('SP. Z O.O.' IN mystring)-1),
-> RIGHT(mystring, LENGTH(mystring)-POSITION('SP. Z O.O.' IN mystring)-9),
-> '<<<') AS resultstring
-> FROM strtest;
+--------------+
| resultstring |
+--------------+
| >>><<< |
| >>>ABC<<< |
| >>>XYZ<<< |
| >>>QWEIOP<<< |
| >>>AAALLL<<< |
+--------------+
5 rows in set (0.00 sec)
To UPDATE the Table
MariaDB [bernd]> UPDATE strtest
-> SET mystring = CONCAT(
-> LEFT (mystring, POSITION('SP. Z O.O.' IN mystring)-1),
-> RIGHT(mystring, LENGTH(mystring)-POSITION('SP. Z O.O.' IN mystring)-9)
-> )
-> WHERE mystring LIKE '%SP. Z O.O.%';
Query OK, 5 rows affected (0.00 sec)
Rows matched: 5 Changed: 5 Warnings: 0
MariaDB [bernd]> SELECT * from strtest;
+----+----------+
| id | mystring |
+----+----------+
| 1 | |
| 2 | ABC |
| 3 | XYZ |
| 4 | QWEIOP |
| 5 | AAALLL |
+----+----------+
5 rows in set (0.00 sec)
MariaDB [bernd]>

Answer 2

If you are using MariaDB, you could use REGEXP_REPLACE() like the next line:
REGEXP_REPLACE(col, regexp, replace)
Here you will find examples about the usage.