MySQL query for string replacement and set String - mysql

I have string data in one cell and column type text.
like example :
Q: {"newColumnName":"xxxx","filterList":[],"columnNames":"pqrs"}
columnNames,filterList,newColumnName are not in fixed position may be change.
i need to replace this above string data to
Need Result:{"columnNames":["pqrs"],"filterList":[],"parameters":{"newColumnName":"xxxx"}}
means i need to search and replace :-
1. "columnNames":"pqrs"------>"columnNames":["pqrs"].
2. "newColumnName":"xxxx" ------>"parameters":{"newColumnName":"xxxx"}.
pqrs and xxxx known to me. It can any string in there.

you can do it with a query like this:
It is ONLY a text replacement
to check
SELECT t.val
, REPLACE(
REPLACE(t.val,'"columnNames":"pqrs"','"columnNames":["pqrs"]')
, '"newColumnName":"xxxx"' , '"parameters":{"newColumnName":"xxxx"}') as result
FROM tt t;
to replace
UPDATE tt
set tt.val =
REPLACE(
REPLACE(tt.val,'"columnNames":"pqrs"','"columnNames":["pqrs"]')
, '"newColumnName":"xxxx"' , '"parameters":{"newColumnName":"xxxx"}');

Related

Why CONCAT does not insert text for the first time into mySQL table?

I am using UPDATE to insert simple text into a table where the field is MEDIUMTEXT (nullable field).
It is strange that it does not work when the field is null initially. If I manually enter at least a one character/space, then it's working.
I want to append the new text into existing text in the field.
UPDATE pen SET
PEN_STATUS = #PenStat,
PEN_STATUS_CHANGE_REASON = CONCAT(PEN_STATUS_CHANGE_REASON,'\n',ChangeDate,':',EmployeeID,':',ChangeReason)
WHERE PEN_ID = PenID;
Why is this?
CONCAT does not handle NULL values. As explained in the MySQL manual:
CONCAT() returns NULL if any argument is NULL.
You want to use COALESCE to handle that use case, like :
UPDATE pen SET
PEN_STATUS = #PenStat,
PEN_STATUS_CHANGE_REASON = CONCAT(
COALESCE(PEN_STATUS_CHANGE_REASON, ''),
'\n',
ChangeDate,
':',
EmployeeID,
':',
ChangeReason
)
WHERE PEN_ID = PenID;
Presumably, because something is NULL. Try using CONCAT_WS() instead:
UPDATE pen
SET PEN_STATUS = #PenStat,
PEN_STATUS_CHANGE_REASON = CONCAT_WS('\n',
PEN_STATUS_CHANGE_REASON,
CONCAT_WS(':', ChangeDate, EmployeeID, ChangeReason
)
)
WHERE PEN_ID = PenID;
CONCAT_WS() ignores NULL arguments. Plus, the separator only needs to be listed once.

Exact string search with LIKE

I have a table column that includes string like:
1,3,10,15
or
2,1,4,5...
Amount of numbers can change. I need a regular expression that will bring me the column that includes exactly "1" for the first string "1,3,10,15".
It shouldn't choose it because of 10 or 15, so "3, 10, 15" for this string, it shouldn't be selected.
If you really want to do this with a like, try this:
Say your column is named numstring.
"," ||numstring||"," like "%,1,%"
Just use:
WHERE (colname LIKE '1,%' OR colname = '1')
as
SELECT * FROM
(
SELECT '1,2,3' as teststring
) as test
WHERE teststring LIKE '1,%'
;
returns the row "1,2,3"
and
SELECT * FROM
(
SELECT '12,22,23' as teststring
) as test
WHERE teststring LIKE '1,%'
;
returns nothing as expected

MySQL Correct title/proper case for more than one string in a field

I have a database which has a field titled 'address1'. If there is only 1 string in this field for a record, I am able to correct the case from eg 'PAULSTOWN' to 'Paulstown', or 'bishopslough' to 'Bishopslough'.
I have done this by creating a function:
CREATE FUNCTION init_cap (s VARCHAR(255))
RETURNS VARCHAR(255) DETERMINISTIC
RETURN CONCAT( UPPER( SUBSTRING( s, 1, 1 ) ) , LOWER( SUBSTRING( s FROM 2 ) ) );
Then using:
UPDATE customer SET address1 = init_cap(address1);
To correct records.
However, this does not fully correct records that contain more than one string, eg 'dalesfort road' will only be corrected to 'Dalesfort road' and not 'Dalesfort Road'. There are also some entries with more than 2 strings.
How could I change the above function to cater for 2 or more strings? Also is that function declared correctly, or should I be using begin and end sections?
It's ok I found the answer at artfulsoftware.com
Now I just need to analyse the code and learn how it works!

How to replace only few characters from a string in mysql?

I have a field urn_sem.studentid that I'd like to replace a few characters in; for example:
ABC/2011/BCOMH_NC/I/12 → ABC/2011/BCOMH/I/12
ABC/2011/BCOMH_NC/I/24 → ABC/2011/BCOMH/I/24
I've tried this query:
SELECT REPLACE(studentid, 'KNC/2011/BCOMH_NC/', ' KNC/2011/BCOMH/')
FROM urn_sem
but it doesn't show the new value.
Do you want this:
update urn_sem
set studentid = REPLACE(studentid, 'KNC/2011/BCOMH_NC/', ' KNC/2011/BCOMH/')
where studentid like '%KNC/2011/BCOMH_NC/%'
The WHERE clause is optional. It ensures that the replace is only on rows that change.
And this sample query does not work?
SELECT REPLACE (studentid, '_', '') FROM urn_sem

MySql: updating a column with the column's content plus something else

I'm don't have a lot of knowledge of MySql (or SQL in general) so sorry for the noobness.
I'm trying to update a bunch of String entries this way:
Lets say we have this:
commands.firm.pm.Stuff
Well I want to convert that into:
commands.firm.pm.print.Stuff
Meaning, Add the .print after pm, before "Stuff" (where Stuff can be any Alphanumerical String).
How would I do this with a MySql Query? I'm sure REGEXP has to be used, but I'm not sure how to go about it.
Thanks
Try something like this. It finds the last period and inserts your string there:
select insert(s, length(s) - instr(reverse(s), '.') + 1, 0, '.print')
from (
select 'commands.firm.pm.Stuff' as s
) a
To update:
update MyTable
set MyColumn = insert(MyColumn, length(MyColumn) - instr(reverse(MyColumn), '.') + 1, 0, '.print')
where MyColumn like 'commands.firm.pm.%'
Perhaps use a str_replace to replace commands.firm.pm to commands.firm.pm.print
$original_str = "commands.firm.pm.15hhkl15k0fak1";
str_replace("commands.firm.pm", "commands.firm.pm.print", $original_str);
should output: commands.firm.pm.print.15hhkl15k0fak1
then update your table with the new value...How to do it all in one query (get column value and do the update), I do not know. All I can think of is you getting the column value in one query, doing the replacement above, and then updating the column with the new value in a second query.
To update rows that end in '.Stuff' only:
UPDATE TableX
SET Column = CONCAT( LEFT( CHAR_LENGTH(Column) - CHAR_LENGTH('.Stuff') )
, '.print'
, '.Stuff'
)
WHERE Column LIKE '%.Stuff'
To update all rows - by appending .print just before the last dot .:
UPDATE TableX
SET Column = CONCAT( LEFT( CHAR_LENGTH(Column)
- CHAR_LENGTH(SUBSTRING_INDEX(Column, '.', -1))
)
, 'print.'
, SUBSTRING_INDEX(Column, '.', -1)
)
WHERE Column LIKE '%.%'