Search for text between delimiters in MySQL

Question

I am trying to extract a certain part of a column that is between delimiters.

e.g. find foo in the following

test \'esf :foo: bar

So in the above I\'d wa

Answer 1

This is what I am extracting from (mainly colon ':' as delimiter but some exceptions), as column theline255 in table loaddata255:

23856.409:0023:trace:message:SPY_EnterMessage (0x2003a) L"{#32769}"      [0081] WM_NCCREATE sent from self wp=00000000 lp=0023f0b0

This is the MySql code (It quickly did what I want, and is straight forward):

select 
time('2000-01-01 00:00:00' + interval substring_index(theline255, '.', 1) second) as hhmmss
, substring_index(substring_index(theline255, ':', 1), '.', -1) as logMilli
, substring_index(substring_index(theline255, ':', 2), ':', -1) as logTid
, substring_index(substring_index(theline255, ':', 3), ':', -1) as logType
, substring_index(substring_index(theline255, ':', 4), ':', -1) as logArea
, substring_index(substring_index(theline255, ' ', 1), ':', -1) as logFunction
, substring(theline255, length(substring_index(theline255, ' ', 1)) + 2) as logText
from loaddata255

and this is the result:

# LogTime, LogTimeMilli, LogTid, LogType, LogArea, LogFunction, LogText
'06:37:36', '409', '0023', 'trace', 'message', 'SPY_EnterMessage', '(0x2003a) L\"{#32769}\"      [0081] WM_NCCREATE sent from self wp=00000000 lp=0023f0b0'

Answer 2

With only one set of delimeters, the following should work:

SUBSTR(
    SUBSTR(fooField,LOCATE(':',fooField)+1),
    1,
    LOCATE(':',SUBSTR(fooField,LOCATE(':',fooField)+1))-1
 )

Answer 3

Here ya go, bud:

SELECT 
  SUBSTR(column, 
    LOCATE(':',column)+1, 
      (CHAR_LENGTH(column) - LOCATE(':',REVERSE(column)) - LOCATE(':',column))) 
FROM table

Yea, no clue why you're doing this, but this will do the trick.

By performing a LOCATE, we can find the first ':'. To find the last ':', there's no reverse LOCATE, so we have to do it manually by performing a LOCATE(':', REVERSE(column)).

With the index of the first ':', the number of chars from the last ':' to the end of the string, and the CHAR_LENGTH (don't use LENGTH() for this), we can use a little math to discover the length of the string between the two instances of ':'.

This way we can peform a SUBSTR and dynamically pluck out the characters between the two ':'.

Again, it's gross, but to each his own.

Answer 4

If you know the position you want to extract from as opposed to what the data itself is:

$colNumber = 2; //2nd position
$sql = "REPLACE(SUBSTRING(SUBSTRING_INDEX(fooField, ':', $colNumber),
                             LENGTH(SUBSTRING_INDEX(fooField, 
                                                    ':', 
                                                    $colNumber - 1)) + 1)";

Answer 5

A combination of LOCATE and MID would probably do the trick.

If the value "test 'esf :foo: bar" was in the field fooField:

MID( fooField, LOCATE('foo', fooField), 3);