Question

I need to split comma delimited string into a second columns
I have the following table :

CL1     POS                 POS2     LENGHT     ALLELE
1       3015108,3015109              5          A
2       3015110,3015200              10         B
3       3015200,3015300              15         C
4       3015450,3015500              20         D
5       3015600,3015700              15         E

I want to split the numbers after the comma into a second column POS2
So it should like that

CL1     POS                 POS2     LENGHT     ALLELE
1       3015108             3015109  5          A
2       3015110             3015200  10         B
3       3015200             3015300  15         C
4       3015450             3015500  20         D
5       3015600             3015700  15         E

So I’ve queried the following :

INSERT INTO MyTable (POS2)
SELECT RIGHT(POS, CHARINDEX(',', POS) + 1 ) FROM MyTable ;


 It returns an error : 
 ERROR 1305 (42000): FUNCTION test.CHARINDEX does not exist

Answer 1

MySQL doesn’t have a built-in CHARINDEX() function. LOCATE() would be the MySQL equivalent.

Using SUBSTRING_INDEX() might be a more succinct way of doing this. Something like this (disclaimer: untested):

SUBSTRING_INDEX(POS, ',', 1) for POS

SUBSTRING_INDEX(POS, ',', -1) for POS2

---

As an aside, I may be misunderstanding what you’re trying to accomplish, but it looks like you might want to UPDATE existing rows, not INSERT new ones? Something like:

UPDATE MyTable SET POS2 = SUBSTRING_INDEX(POS, ',', -1);
UPDATE MyTable SET POS = SUBSTRING_INDEX(POS, ',', 1);