Count all elements in an array - sql

I have a table that I save some data include list of numbers.
like this:
numbers
(null)
،42593
،42593،42594،36725،42592،36725،42592
،42593،42594،36725،42592
،31046،36725،42592
I would like to count the number elements in every row in SQL Server
count
0
1
6
4
3

You could use a replacement trick here:
SELECT numbers,
COALESCE(LEN(numbers) - LEN(REPLACE(numbers, ',', '')), 0) AS num_elements
FROM yourTable;
The above trick works by counting the number of commas (assuming your data really has commas as separators). For example, your last sample data point was:
,31046,36725,42592 => length is 18
310463672542592 => length is 15
Hence the difference in lengths correctly yields the right number of elements.

Another idea is to useSTRING_SPLIT:
SELECT y.numbers,
(SELECT COUNT(Value) - 1
FROM string_split(COALESCE(y.numbers,''),',')) AS num_elements
FROM yourtable AS y;
I know this looks a bit unhandy on first glance due to this strange -1 in the second line and the COALESCE in the third line. So why do I talk about this option?
Well, the strange thing in your case which causes these difficulties in my query is that your rows always start with a comma.
This is quite weird and it would be much easier without this first comma in every row.
Let's assume you remove this comma in future. Then this will become really easy and good readable:
SELECT y.numbers,
(SELECT COUNT(Value)
FROM string_split(y.numbers,',')) AS num_elements
FROM yourtable AS y;
Try out: db<>fiddle

your data
CREATE TABLE yourtable(
numbers VARCHAR(max)
);
INSERT INTO yourtable
(numbers) VALUES
(null),
('،42593'),
('،42593،42594،36725،42592،36725،42592'),
('،42593،42594،36725،42592'),
('،31046،36725،42592');
you need ISNULL and len
select
ISNULL(len(numbers) - len(replace(numbers,'،','')) ,0) count
from yourtable
the other way is by using IIF and string_split as follows
SELECT IIF(count < 0, 0, count) count
FROM   (SELECT (SELECT Count(*) - 1
                FROM   STRING_SPLIT (Replace(Replace(numbers, 'R', ''), '،',
                                     'R'), 'R'
                       )) AS
               'count'
        FROM   yourtable) A
dbfiddle

Related

How to get tally of unique words using only SQL?

How do you get a list of all unique words and their frequencies ("tally") in one text column of one table of an SQL database? An answer for any SQL dialect in which this is possible would be appreciated.
In case it helps, here's a one-liner that does it in Ruby using Sequel:
Hash[DB[:table].all.map{|r| r[:text]}.join("\n").gsub(/[\(\),]+/,'').downcase.strip.split(/\s+/).tally.sort_by{|_k,v| v}.reverse]
To give an example, for table table with 4 rows with each holding one line of Dr. Dre's Still D.R.E.'s refrain in a text field, the output would be:
{"the"=>4,
"still"=>3,
"them"=>3,
"for"=>2,
"d-r-e"=>1,
"it's"=>1,
"streets"=>1,
"love"=>1,
"got"=>1,
"i"=>1,
"and"=>1,
"beat"=>1,
"perfect"=>1,
"to"=>1,
"time"=>1,
"my"=>1,
"taking"=>1,
"girl"=>1,
"low-lows"=>1,
"in"=>1,
"corners"=>1,
"hitting"=>1,
"world"=>1,
"across"=>1,
"all"=>1,
"gangstas"=>1,
"representing"=>1,
"i'm"=>1}
This works, of course, but is naturally not as fast or elegant as it would be to do it in pure SQL - which I have no clue if that's even in the realm of possibilites...
I guess it would depend on how the SQL database would look like. You would have to first turn your 4 row "database" into a data of single column, each row representing one word. To do that you could use something like String_split, where every space would be a delimiter.
STRING_SPLIT('I'm representing for them gangstas all across the world', ' ')
https://www.sqlservertutorial.net/sql-server-string-functions/sql-server-string_split-function/
This would turn it into a table where every word is a row.
Once you've set up your data table, then it's easy.
Your_table:
[Word]
I'm
representing
for
them
...
world
Then you can just write:
SELECT Word, count(*)
FROM your_table
GROUP BY Word;
Your output would be:
Word | Count
I'm 1
representing 1
I had a play using XML in sql server. Just an idea :)
with cteXML as
(
select *
,cast('<wd>' + replace(songline,' ' ,'</wd><wd>') + '</wd>' as xml) as XMLsongline
from #tSongs
),cteBase as
(
select p.value('.','nvarchar(max)') as singleword
from cteXML as x
cross apply x.XMLsongline.nodes('/wd') t(p)
)
select b.singleword,count(b.singleword)
from cteBase as b
group by b.singleword

SQL Query to compare the first X characters of 2 fields in a table

Say I have a table named 'Parts'. I am looking to create a SQL query that compares the first X characters of two of the fields, let's call them 'PartNum1' and 'PartNum2'. For example, I would like to return all records from 'Parts' where the first 6 characters of 'PartNum1' equals the first 6 characters of 'PartNum2'.
Parts
PartNum1
PartNum2
12345678
12345600
12388888
12345000
12000000
14500000
the query would only return row 1 since the first 6 characters match. MS SQL Server 2017 in case that makes a difference.
If they are strings, use left():
left(partnum1, 6) = left(partnum2, 6)
This would be appropriate in a where, on, or case expression. Note that using left() would generally prevent the use of indexes. If this is for a join and you care about performance, you might want to include a computed column with the first six characters.
you can try something like this. I am assuming datatype as integer. You can set size of varchar based on length of fields.
select *
from Parts
WHERE SUBSTRING(CAST(PartNum1 AS VARCHAR(max)), 1,6) = SUBSTRING(CAST(PartNum2 AS VARCHAR(max)), 1,6)
You can go for simple division to see if the numerator matches for those partnumbers.
DECLARE #table table(partnum int, partnum2 int)
insert into #table values
(12345678, 12345600)
,(12388888, 12345000)
,(12000000, 14500000);
select * from #table where partnum/100 = partnum2/100
partnum
partnum2
12345678
12345600

Query to find if a column contains both number and decimal only

I have a column to check if contains number from 0-9 and a decimal. Since in the version of SQL am using the below does not seem working
select *
from tablename
whwere columnname like '%[^.0-9]%'
Also tried using column name like '%[0-9]%' and columnname not like '%.%' but if there is a negative sign it is not getting captured. Please advise.
The column data type is float. So can someone provide me a query to check if the column contains values from 0-9 and also it can contain decimal values these two are permitted. If say for example if I have value 9,9.99 ,-1.24 the query should output -1.24 I need this value other than decimal and number –
The issue with your LIKE clause is bad predicate logic ...like '%[^.0-9]%'should be NOT LIKE '%[^0-9.]%'
Take this sample data.
DECLARE #table TABLE (SomeNbr VARCHAR(32));
INSERT #table VALUES ('x'),('0'),('0.12'),('999'),('-29.33'),('88.33.22'),('9-9-'),('11-');
What you were trying to do would be accomplished like this:
SELECT t.someNbr
FROM #table AS t
WHERE someNbr NOT LIKE '%[^0-9.]%';
The problem here is we'll also return "88.33.22" and miss "-29.33", both valid float values. You can handle hyphens by adding a hyphen to your LIKE pattern:
SELECT t.someNbr, LEN(t.SomeNbr)-LEN(REPLACE(t.SomeNbr,'.',''))
FROM #table AS t
WHERE someNbr NOT LIKE '%[^0-9.-]%';
But now we also pick up "9-9-" and stuff with 2+ dots. To ensure that each starts with a number OR a hyphen, to ensure hyphens only exist in the front of the string (if at all) and that we a maximum of one dot:
--==== This will do a good job but can still be broken
SELECT t.someNbr
FROM #table AS t
WHERE someNbr NOT LIKE '%[^0-9.-]%' -- Can only contain numbers, dots and hyphens
AND LEN(t.SomeNbr)-LEN(REPLACE(t.SomeNbr,'.','')) < 2 -- can have up to 1 dot
AND LEN(t.SomeNbr)-LEN(REPLACE(t.SomeNbr,'-','')) < 2 -- can have up to 1 hyphen
AND PATINDEX('%-%',t.SomeNbr) < 2 -- hyphen can only be in the front
This does the trick and returns:
someNbr
--------------------------------
0
0.12
999
-29.33
All that said - **DONT DO THIS ANY OF THIS ^^^ **. There is no need to parse numbers in this way except to show others why not to. I can still break this. They way I return valid floats in a scenario like this is with TRY_CAST or TRY_CONVERT. This returns what you need and will perform better.
--==== Best Solution
SELECT t.someNbr
FROM #table AS t
WHERE TRY_CAST(t.SomeNbr AS float) IS NOT NULL;

How to implement MAX function on a text column in SQL Server?

I'm using SQL Server 2005 and have a column that contains serial numbers, which are nvarchar(50).
My problem is selecting max(serial_no) from the table. The serial numbers used to have a length of 7 only but new ones are now 15. Whenever I select the max, I get a result with a length of 7, which means that data is old. I also can't filter it to only select from records which have a length of 15 because then i'll miss some other data on my query.
Old serial numbers look like this...
'SNGD001'
..., and new ones look like this:
'SN14ABCD0000001'
Edit: I tried creating a dummy table without the old serial numbers (5 characters long), and I'm getting correct results.
As has been mentioned, your question is a bit hard to follow. If the max value could be either one of your old serial numbers or one of your new ones, I believe the following should do the trick:
SELECT MAX(RIGHT('0000000' + REVERSE(LEFT(REVERSE(YourTextColumn), PATINDEX('%[a-z]%', REVERSE(YourTextColumn)) - 1)), 7))
FROM YourTable
It finds the first non numeric character from the right keeping everything to the right of that. It then left zero pads the resulting numeric string to 7 characters and applies the MAX function.
Your question is a little tough to follow without good sample data to get a bearing on. I suggest for future, you show a few more examples of data to get better context, especially with sequencing. Now, your desire to get the MAX() of a "serial_no" from your table appears you need so you get detect the next sequential serial number to assign. However, your serial number appears to be a concatenation of a prefix string and then sequential. So, if I were to look at your brief data MIGHT HAVE BEEN along the lines of (last 3 digits are the sequential serializations)
SNGD001
SNGD002
SNGD003
...
SNGD389, etc...
and your new data with the last (last 7 digits are sequential serializations)
SN14ABCD0000001
SN14ABCD0000002
SN14ABCD0000003
...
SN14ABCD0002837
If this is correct, then you basically need to look at the max based on the leading 3 or 8 characters of the string PLUS the converted suffix numeric sequence. For starters, lets go with that to see if we are on the correct track or not, then you can easily concatenate the prefix and sequence number together at the end for determining the next available number.
So, based on the above samples, you may want to know that for each prefix, the last number of
SNGD389 and
SN14ABCD0002837 respective per their prefix
If the above is correct, I might start with...
select
case when LEN( RTRIM( yt.serial_no )) = 7
then LEFT( yt.serial_no, 4 )
else LEFT( yt.serial_no, 8 ) end as SerialPrefix,
MAX( case when LEN( RTRIM( yt.serial_no )) = 7
then CONVERT(INT, RIGHT( yt.serial_no, 3 ))
else CONVERT(INT, RIGHT( yt.serial_no, 7 )) end ) as SerialSequence
from
YourTable yt
group by
case when LEN( RTRIM( yt.serial_no )) = 7
then LEFT( yt.serial_no, 4 )
else LEFT( yt.serial_no, 8 ) end as SerialPrefix
Which would result in (based on sample data I presented)
SerialPrefix SerialSequence
SNGD 389
SN14ABCD 0002837
Of which since the serial sequence column being numeric, you could add 1 to it, then left-zero fill a string and concatenate the two back together such as to create
SNGD390
SN14ABCD0002838

How can I use LEFT & RIGHT Functions in SQL to get last 3 characters?

I have a Char(15) field, in this field I have the data below:
94342KMR
947JCP
7048MYC
I need to break down this, I need to get the last RIGHT 3 characters and I need to get whatever is to the LEFT. My issue is that the code on the LEFT is not always the same length as you can see.
How can I accomplish this in SQL?
Thank you
SELECT RIGHT(RTRIM(column), 3),
LEFT(column, LEN(column) - 3)
FROM table
Use RIGHT w/ RTRIM (to avoid complications with a fixed-length column), and LEFT coupled with LEN (to only grab what you need, exempt of the last 3 characters).
if there's ever a situation where the length is <= 3, then you're probably going to have to use a CASE statement so the LEFT call doesn't get greedy.
You can use RTRIM or cast your value to VARCHAR:
SELECT RIGHT(RTRIM(Field),3), LEFT(Field,LEN(Field)-3)
Or
SELECT RIGHT(CAST(Field AS VARCHAR(15)),3), LEFT(Field,LEN(Field)-3)
Here an alternative using SUBSTRING
SELECT
SUBSTRING([Field], LEN([Field]) - 2, 3) [Right3],
SUBSTRING([Field], 0, LEN([Field]) - 2) [TheRest]
FROM
[Fields]
with fiddle
select right(rtrim('94342KMR'),3)
This will fetch the last 3 right string.
select substring(rtrim('94342KMR'),1,len('94342KMR')-3)
This will fetch the remaining Characters.