I have a table in an SQLite db which has multiple columns with leading '='. I understand that I can use...
SELECT TRIM(`column1`, '=') FROM table;
to clean one column however I get a syntax error if I try for example, this...
SELECT TRIM(`column1`, `column2`, `column3`, '=') FROM table;
Due to incorrect number of arguments.
Is there a more efficient way of writing this code than applying the trim to each column separately like this?
SELECT TRIM(`column1`,'=')as `col1`, TRIM(`column2`,'=')as `col2`, TRIM(`column3`,'=')as `col3` FROM table;
How SQLite guide tells:
trim(X,Y)
The trim(X,Y) function returns a string formed by removing any and all
characters that appear in Y from both ends of X. If the Y argument is
omitted, trim(X) removes spaces from both ends of X.
You have only two parameters, so it's impossible apply it one shot on 3 columns table.
The first parameter is a column, or variable on you can apply trim. The second parameter is a character to change.
Related
I have a column that I need to select but it has an inconsistent amount of numbers/formatting in the beginning
The column values are ideally supposed to be structured like:
# Question_-_Answer
But here are some examples which make it hard to remove the numbers in the beginning
0 Question1_-_50-60
1.Question_-_apple
12Question_-_40/50
13 Question_-_orange
14.Question_-_apple
15. Question_-_orange2
Is there a way I can query this column so that it ignores everything until the first alphabetical character while also not removing any characters/alphanumerical values in the question and answer portion?
You can use PATINDEX and STUFF to achieve this:
SELECT STUFF(V.YourString,1,PATINDEX('%[A-z]%',V.YourString)-1,'')
FROM (VALUES('0 Question1_-_50-60'),
('1.Question_-_apple'),
('12Question_-_40/50'),
('13 Question_-_orange'),
('14.Question_-_apple'),
('15. Question_-_orange2'))V(YourString);
This removes all characters up to the first alpha character.
I want to split a varchar column on a certain expression and keep the left hand side of the result.
My column looks as follows:
varchar_col
keep_this__discard_this
keep_this_too__discard_this
I want to split all the strings on the double underscore ('__') and keep whatever comes before it. How can this be done in SQLite?
You can use:
select substr(varchar_col, 1, instr(varchar_col, '__') - 1)
Here is a db<>fiddle.
I have a table which contains some bad data I am trying to clean up.
An example of the fields is below
36234735HAN876
2342JOE9823
554444PUT003
What I want to do is remove all the numeric characters before the first alphabetical character so it would look like the below:
HAN876
JOE9823
PUT003
What would be the best way to achieve this? I have used the below method but this can only be used to extract ALL numeric from the string, not the ones before the alphabetical characters
How to get the numeric part from a string using T-SQL?
You could achieve this using PATINDEX to locate the first position of an alphabetical character in the string, and then use SUBSTRING to only return the characters after that position:
CREATE TABLE #temp (val VARCHAR(50));
INSERT INTO #temp VALUES ('36234735HAN876'), ('2342JOE9823'), ('554444PUT003'), ('TEST1234');
SELECT val,
SUBSTRING(val, PATINDEX('%[A-Z]%', val), LEN(val)) AS output
FROM #temp;
DROP TABLE #temp;
Outputs:
val output
36234735HAN876 HAN876
2342JOE9823 JOE9823
554444PUT003 PUT003
TEST1234 TEST1234
Note that I have created a temporary table with a column named val. You should change this to work with whatever the actual column is called.
About case sensitivity: If you are using a non-case sensitive collation this will work without issue. If your collation is case sensitive then you may need to alter the pattern being matched to cater for upper- and lower-case letters.
Use PATINDEX to find the first non-numeric character (or first alpha character, depending on the logic) and STUFF to remove them:
SELECT STUFF(V.YourString,1,ISNULL(NULLIF(PATINDEX('%[^0-9]%',V.YourString),0)-1,0),'')
FROM (VALUES('36234735HAN876'),
('2342JOE9823'),
('554444PUT003'),
('ABC123'))V(YourString)
If the logic is the first alpha character, instead of the first non-numeric, then the pattern would be [A-z].
The NULLIF and ISNULL are in there for when/if the string starts with a alpha/non-numeric and thus doesn't cause STUFF to error due to the 3rd parameter being -1. The is demonstrated with the additional example I put into the sample data ('ABC123').
I need some help with the next. I have a field text in SQL, this record a list of times sepparates with '|'. For example
'14613|15474|3832|148|5236|5348|1055|524' Each value is a time in milliseconds. This field could any length, for example is perfect correct '3215|2654' or '4565' (only 1 value). I need get this field and replace all number with -1000 value.
So '14613|15474|3832|148|5236|5348|1055|524' will be '-1000|-1000|-1000|-1000|-1000|-1000|-1000|-1000'
Or '3215|2654' => '-1000|-1000' Or '4565' => '-1000'.
I try use regexp_replace(times_field,'[[:digit:]]','-1000','g') but it replace each digit, not the complete number, so in this example:
'3215|2654' than must be '-1000|-1000', i get:
'-1000-1000-1000-1000|-1000-1000-1000-1000', I try with other combinations and more options of regexp but i'm done.
Please need your help, thanks!!!.
We can try using REGEXP_REPLACE here:
UPDATE yourTable
SET times_field = REGEXP_REPLACE(times_field, '\y[0-9]+\y', '-1000', 'g');
If instead you don't really want to alter your data but rather just view your data this way, then use a select:
SELECT
times_field,
REGEXP_REPLACE(times_field, '\y[0-9]+\y', '-1000', 'g') AS times_field_replace
FROM yourTable;
Note that in either case we pass g as the fourtb parameter to REGEXP_REPLACE to do a global replacement of all pipe separated numbers.
[[:digit:]] - matches a digit [0-9]
+ Quantifier - matches between one and unlimited times, as many times as possible
your regexp must look like
regexp_replace(times_field,'[[:digit:]]+','-1000','g')
Column xy of type 'nvarchar2(40)' in table ABC.
Column consists mainly of numerical Strings
how can I make a
select to_number(trim(xy)) from ABC
query, that ignores non-numerical strings?
In general in relational databases, the order of evaluation is not defined, so it is possible that the select functions are called before the where clause filters the data. I know this is the case in SQL Server. Here is a post that suggests that the same can happen in Oracle.
The case statement, however, does cascade, so it is evaluated in order. For that reason, I prefer:
select (case when NOT regexp_like(xy,'[^[:digit:]]') then to_number(xy)
end)
from ABC;
This will return NULL for values that are not numbers.
You could use regexp_like to find out if it is a number (with/without plus/minus sign, decimal separator followed by at least one digit, thousand separators in the correct places if any) and use it like this:
SELECT TO_NUMBER( CASE WHEN regexp_like(xy,'.....') THEN xy ELSE NULL END )
FROM ABC;
However, as the built-in function TO_NUMBER is not able to deal with all numbers (it fails at least when a number contains thousand separators), I would suggest to write a PL/SQL function TO_NUMBER_OR_DEFAULT(numberstring, defaultnumber) to do what you want.
EDIT: You may want to read my answer on using regexp_like to determine if a string contains a number here: https://stackoverflow.com/a/21235443/2270762.
You can add WHERE
SELECT TO_NUMBER(TRIM(xy)) FROM ABC WHERE REGEXP_INSTR(email, '[A-Za-z]') = 0
The WHERE is ignoring columns with letters. See the documentation