I need to get numbers with a variable length out of a string and sum them.
The strings got the following format:
EH:NUMBER=SomeOtherStuff->Code
I'm extracting the code via RIGHT() and join with another table to get the group right, at the moment I'm using sum to get it together via date:
SUM(CASE WHEN (MONTH(data.DATE1) = 5 AND YEAR(data.DATE1) = YEAR(GETDATE())) THEN 1 ELSE 0 END) N'Mai',
I then need to sum the numbers from the string and not the number of rows.
Some Examples:
Month1 EH:1=24->ZTM
Month1 EH:4=13-21->LKm
Month2 EH:3=34,33,43->LKm
Month2 EH:7=12,92-29,29->LKm
Month2 EH:5=24-26,11,21,22->ZOL
What i need:
Material - Month1 - Month2
ZTM - 1 - 0
LKM - 4 - 10
ZOL - 0 - 5
Could you help me please?
Greetings
Short version:
What you are looking for is SUBSTRING.
Longer version:
To get the the sum of the numerical value of NUMBER you need think about how break it down.
I'd recommend following these steps:
Extract the NUMBER part from the string. This should be done with SUBSTRING (much like you extract Code with RIGHT). To get the start and and length och your substring use charindex ( or patindex if you like).
Convert the NUMBER part to a numerical value with cast (or convert or what you are familiar with)
Now you can do your aggregation.
So SUM(CAST(SUBSTRING(*this part you will have to figure out by yourself)) as correct numerical data type)).
I'll let you figure out the values to insert by yourself and would recommend to first find the positions of the delimiting characters, then extract the NUMBER part, then get the numerical value .... you get it .
This to gain a better understanding of what you are actually doing.
Cheers, and good luck with your assignment
Martin
Related
I would like to check if a specific column in one of my tables meets the following conditions:
String must contain at least three characters
String must contain at least two different numbers [e.g. 123 would work but 111 would not]
Characters which are allowed in the string:
Numbers (0-9)
Uppercase letters
Lowercase letters
Underscores (_)]
Dashes (-)
I have some experience with Regex but am having issues with Snowflake's syntax. Whenever I try using the '?' regex character (to mark something as optional) I receive an error. Can someone help me understand a workaround and provide a solution?
What I have so far:
SELECT string,
LENGTH(string) AS length
FROM tbl
WHERE REGEXP_LIKE(string,'^[0-9]+{3,}[-+]?[A-Z]?[a-z]?$')
ORDER BY length;
Thanks!
Your regex looks a little confusing and invalid, and it doesn't look like it quite meets your needs either. I read this expression as a string that:
Must start with one or more digits, at least 3 or more times
The confusing part to me is the '+' is a quantifier, which is not quantifiable with {3,} but somehow doesn't produce an error for me
Optionally followed by either a dash or plus sign
Followed by an uppercase character zero or one times (giving back as needed)
Followed by and ending with a lowercase character zero or one times (giving back as needed)
Questions
You say that your string must contain 3 characters and at least 2 different numbers, numbers are characters but I'm not sure if you mean 3 letters...
Are you considering the numbers to be characters?
Does the order of the characters matter?
Can you provide an example of the error you are receiving?
Notes
Checking for a second digit that is not the same as the first involves the concept of a lookahead with a backreference. Snowflake does not support backreferences.
One thing about pattern matching with regular expressions is that order makes a difference. If order is not of importance to you, then you'll have multiple patterns to match against.
Example
Below is how you can test each part of your requirements individually. I've included a few regexp_substr functions to show how extraction can work to check if something exists again.
Uncomment the WHERE clause to see the dataset filtered. The filters are written as expressions so you can remove any/all of the regexp_* columns.
select randstr(36,random(123)) as r_string
,length(r_string) AS length
,regexp_like(r_string,'^[0-9]+{3,}[-+]?[A-Z]?[a-z]?$') as reg
,regexp_like(r_string,'.*[A-Za-z]{3,}.*') as has_3_consecutive_letters
,regexp_like(r_string,'.*\\d+.*\\d+.*') as has_2_digits
,regexp_substr(r_string,'(\\d)',1,1) as first_digit
,regexp_substr(r_string,'(\\d)',1,2) as second_digit
,first_digit <> second_digit as digits_1st_not_equal_2nd
,not(regexp_instr(r_string,regexp_substr(r_string,'(\\d)',1,1),1,2)) as first_digit_does_not_appear_again
,has_3_consecutive_letters and has_2_digits and first_digit_does_not_appear_again as test
from table(generator(rowcount => 10))
//where regexp_like(r_string,'.*[A-Za-z]{3,}.*') // has_3_consecutive_letters
// and regexp_like(r_string,'.*\\d+.*\\d+.*') // has_2_digits
// and not(regexp_instr(r_string,regexp_substr(r_string,'(\\d)',1,1),1,2)) // first_digit_does_not_appear_again
;
Assuming the digits need to be contiguous, you can use a javascript UDF to find the number in a string with with the largest number of distinct digits:
create or replace function f(S text)
returns float
language javascript
returns null on null input
as
$$
const m = S.match(/\d+/g)
if (!m) return 0
const lengths = m.map(m=> [...new Set (m.split(''))].length)
const max_length = lengths.reduce((a,b) => Math.max(a,b))
return max_length
$$
;
Combined with WHERE-clause, this does what you want, I believe:
select column1, f(column1) max_length
from t
where max_length>1 and length(column1)>2 and column1 rlike '[\\w\\d-]+';
Yielding:
COLUMN1 | MAX_LENGTH
------------------------+-----------
abc123def567ghi1111_123 | 3
123 | 3
111222 | 2
Assuming this input:
create or replace table t as
select * from values ('abc123def567ghi1111_123'), ('xyz111asdf'), ('123'), ('111222'), ('abc 111111111 abc'), ('12'), ('asdf'), ('123 456'), (null);
The function is even simpler if the digits don't have to be contiguous (i.e. count the distinct digits in a string). Then core logic changes to:
const m = S.match(/\d/g)
if (!m) return 0
const length = [...new Set (m)].length
return length
Hope that's helpful!
I have an array that contains multiple dates in the format yyyymmdd, stored as a 50x1 double. I am trying to pull out the year,month, and day so I can use datenum to assign each date a serial number.
Indexing an individual date, converting the using str2num, then indexing and pulling the appropriate values works fine, but when I try to loop through the list of dates it doesn't work- only variations of the number 2 are returned.
dates = [20180910; 20180920; 20181012; 20181027; 20181103; 20181130; 20181225];
% version1
datesnums=num2str(dates); % dates is a list of dates stored as
integers
for i=1:length(datesnums)
pullyy=str2num(datesnums(1:4));
pullmm=str2num(datesnums(5:6));
pulldd=str2num(datesnums(7:8));
end
As well as
%version2
datesnums=num2str(dates,'%d')
for i = 1:length(datesnums)
dd=datenum(str2num(datesnums(i(1:4))),str2num(datesnums(i(5:6))),
str2num(datesnums(i(7:8))));
end
I'm trying to generate a new array that is just the serial numbers of the input dates. In the examples shown, I am only getting single integer values, which I know is because the loop is incorrect and I get errors that say "Index exceeds the number of array elements (1)." for version 1. When I've gotten it to successfully loop through everything, the outputs are just '2222','22,'22' for every single date which is incorrect. What am I doing wrong? Do I need to incorporate a cell array?
To get all the years, month, and days in a loop:
datesnums=num2str(dates);
for i=1:size(datesnums, 1)
pullyy(i) = str2num(datesnums(i,1:4));
pullmm(i) = str2num(datesnums(i,5:6));
pulldd(i) = str2num(datesnums(i,7:8));
end
Actually, you can do this without a loop:
pullyy = str2num(datesnums(:,1:4));
pullmm = str2num(datesnums(:,5:6));
pulldd = str2num(datesnums(:,7:8));
Explanation:
If for example the dates vector is a [6x1] array:
dates =[...
20190901
20170124
20191215
20130609
20141104
20190328];
Than datesnums=num2str(dates); creates a char matrix of size [6x8] where each row corresponds to one element in dates:
datesnums =
6×8 char array
'20190901'
'20170124'
'20191215'
'20160609'
'20191104'
'20190328'
So in the loop you need to refer to the row index for each date and and the column indices to extract the years, month, and days.
The easiest solution I can think of is:
SN = datenum(num2str(dates),'yyyymmdd')
You only have to specify the date format which is 'yyyymmdd'
I have a cell array called BodyData in MATLAB that has around 139 columns and 3500 odd rows of skeletal tracking data.
I need to extract all rows between two string values (these are timestamps when an event happened) that I have
e.g.
BodyData{}=
Column 1 2 3
'10:15:15.332' 'BASE05' ...
...
'10:17:33:230' 'BASE05' ...
The two timestamps should match a value in the array but might also be within a few ms of those in the array e.g.
TimeStamp1 = '10:15:15.560'
TimeStamp2 = '10:17:33.233'
I have several questions!
How can I return an array for all the data between the two string values plus or minus a small threshold of say .100ms?
Also can I also add another condition to say that all str values in column2 must also be the same, otherwise ignore? For example, only return the timestamps between A and B only if 'BASE02'
Many thanks,
The best approach to the first part of your problem is probably to change from strings to numeric date values. In Matlab this can be done quite painlessly with datenum.
For the second part you can just use logical indexing... this is were you put a condition (i.e. that second columns is BASE02) within the indexing expression.
A self-contained example:
% some example data:
BodyData = {'10:15:15.332', 'BASE05', 'foo';...
'10:15:16.332', 'BASE02', 'bar';...
'10:15:17.332', 'BASE05', 'foo';...
'10:15:18.332', 'BASE02', 'foo';...
'10:15:19.332', 'BASE05', 'bar'};
% create column vector of numeric times, and define start/end times
dateValues = datenum(BodyData(:, 1), 'HH:MM:SS.FFF');
startTime = datenum('10:15:16.100', 'HH:MM:SS.FFF');
endTime = datenum('10:15:18.500', 'HH:MM:SS.FFF');
% select data in range, and where second column is 'BASE02'
BodyData(dateValues > startTime & dateValues < endTime & strcmp(BodyData(:, 2), 'BASE02'), :)
Returns:
ans =
'10:15:16.332' 'BASE02' 'bar'
'10:15:18.332' 'BASE02' 'foo'
References: datenum manual page, matlab help page on logical indexing.
I have a date cell array which is read from a csv file. The format is below:
date =
'2008.12.01'
'2008.12.02'
'2008.12.03'
'2008.12.04'
'2008.12.05'
... ...
And I want to:
turn the cell array to a string array,
use the strread() to read its "yyyy","mm" and "dd" value into 3 double array [year,mm,dd],
use the datenummx() to turn [year,mm,dd] into date seriel num.
After i use
date = char(date);
the date array become like this:
date =
2008.12.01
2008.12.02
2008.12.03
2008.12.04
2008.12.05
... ...
which I think the result is what i want...
But after I use the strread(), it gives me odd result.
[year,month,day]=strread(date,'%d%d%d','delimiter','.');
year =
-1
0
0
0
0
... ...
BUT if I use the code below, the strread() can give me the right answer:
s = sprintf('2008.12.01')
s =
2008.12.01
[year,month,day]=strread(s,'%d%d%d','delimiter','.')
year =
2008
month =
12
day =
1
And I checked in the matlab that both the "date" and "s" is a char array.(by using function 'ischar' and simply display both)...
But why do the strread() give differnt results?
Can anyone answer?
by the way, I use the MatLab v6.5.(for my own reason, so please don't comment by asking "why not use a higher version")....
Your problem is this line:
date = char(date);
It does not create an array of strings, there is no array of strings in matlab. It creates an array of chars. As you already noticed, your strread-line is fine if you input a single date, so input each date form your original cell array individually:
for idx=1:numel(date)
[year(idx),month(idx),day(idx)]=strread(date{idx},'%d%d%d','delimiter','.');
end
Preallocation of year, month and day improves the performance.
I have a SQL entry that is of type hex (varbinary) and I want to do a SELECT COUNT for all the entries that have this hex value ending in 1.
I was thinking about using CONVERT to make my hex into a char and then use WHERE my_string LIKE "%1". The thing is that varchar is capped at 8000 chars, and my hex is longer than that.
What options do I have?
Varbinary actually works with some string manipulation functions, most notably substring. So you can use eg.:
select substring(yourBinary, 1, 1);
To get the first byte of your binary column. To get the last bit then, you can use this:
select substring(yourBinary, len(yourBinary), 1) & 1;
This will give you zero if the bit is off, or one if it is on.
However, if you really only have to check at most the last 4-8 bytes, you can easily use the bitwise operators on the column directly:
select yourBinary & 1;
As a final note, this is going to be rather slow. So if you plan on doing this often, on large amounts of data, it might be better to simply create another bit column just for that, which you can index. If you're talking about at most a thousand rows or so, or if you don't care about speed, fire away :)
Check last four bits = 0001
SELECT SUM(CASE WHEN MyColumn % 16 IN (-15,1) THEN 1 END) FROM MyTable
Check last bit = 1
SELECT SUM(CASE WHEN MyColumn % 2 IN (-1,1) THEN 1 END) FROM MyTable
If you are wondering why you have to check for negative moduli, try SELECT 0x80000001 % 16
Try using this where
WHERE LEFT(my_string,1) = 1
It it's text values ending in 1 then you want the Right as opposed to the Left
WHERE RIGHT(my_string,1) = 1