Let's say, we have this table:
STUDENT | START | END
1 |1998-1-1 |2001-1-1
2 |1999-1-1 |2001-1-1
3 |2000-1-1 |2004-1-1
4 |2000-1-1 | NULL
I'm trying to do is:
Count number of students between start and end dates!
Looks like you need to use a basic COUNT aggregate:
SELECT COUNT(Student)
FROM YourTable
WHERE Start >= #Start
AND End <= #End
I've used >= and <= respectively around the start and end date fields. Feel free to change to > or < as needed. It was unclear from your question whether you wanted between a specific field or if you were checking for a range between those two fields.
Use the between Operator and COUNT aggregate function
SELECT COUNT(student) column_name(s)
FROM table_name
WHERE column_name
BETWEEN value1 AND value2
Between can be used with text so insert the dates where the values are,
Read more here if you still don't understand
EDIT : That should work, sorry about the error
http://www.w3schools.com/sql/sql_between.asp
Related
I have a table in database as "EXPERIENCE RANGE" with rows as (I can also edit this table according to my need)
0
0.5
1
2
3
5
10
20
I have total experience as integer. I need to display the range in which it lies.
Example - for experience of 8, Range will be 5 - 10
I need to write a sql query. Any ideas will be quite helpful as I am new to SQL.
I cannot hard code it..need to take values from tables only.
Assuming that you are using Oracle, the following query works fine with your existing table:
SELECT
( SELECT MAX( value ) FROM experience_range WHERE value <= :search_value ) AS range_start,
( SELECT MIN( value ) FROM experience_range WHERE value > :search_value ) AS range_end
FROM dual;
No need to hardcode the values, and no need to store the lower and upper bounds redundantly.
you can do it with CASE Expression, the syntax is:
SELECT
CASE
WHEN experience >= 0 and experience <= 4 THEN '0-4'
WHEN experience >= 5 and experience <= 10 THEN '5-10'
.....
ELSE 'No Range'
END as Range
FROM Table_Name
If you do need to store the ranges in a table, I would personally suggest altering the structure of the range table (Assuming you are able to), maybe something like:
|--------------------------------------|
|ID|DESCRIPTION|LOWER_LIMIT|UPPER_LIMIT|
|1 | 0 - 0.5 | 0 | 0.5 |
|2 | 0.5 - 1 | 0.5 | 1 |
...
Then you could get your range by running something like:
SELECT DESCRIPTION FROM [RANGES] WHERE <VALUE> >= LOWER_LIMIT AND <VALUE> < UPPER_LIMIT
EDIT - Mikhail's answer also works, defining the ranges within the query itself is also an option and probably simpler providing you don't need to get these ranges from several reports. (That would require editing every report/query individually)
EDIT 2 - I see you are not able to hardcode the ranges, in which case the above would be best. Can I ask why you are unable to hardcode them?
I have table with two columns. Depending on the length of the data in one column, I need to join the next column. How can i proceed with this. I have the base SQL up but i cant join the columns together and display both data into one table.
The current table is like this :
ID Code
---------- ----------
ST01 00
ST0105 05
ET2256 56
After a SELECT QUERY, I would like to have
ID
----------
ST0100
ST0105
ET2256
As you can see when ST01 is lesser than 5 characters i will need to add the Code column to it. When the length of the ID is more i do not need to add. How can i achieve. The DB is in production am I am unable to edit, cause all the old applications are configured and running. But the application which I am building uses the 7 character format. So I cant edit the table. I will need to do a select statement only.
SELECT
CASE ID
WHEN ((LEN(ID))<>5) THEN ID=(RTRIM(ID)+LTRIM(Code))
FROM tblID
ORDER BY ID DESC
Based on your explanation I'm guessing:
SELECT
CASE
WHEN ((LEN(ID))<5) THEN (RTRIM(ID)+LTRIM(Code)) ELSE ID END AS ID
FROM tblID
ORDER BY ID DESC
The syntax of your CASE was a bit off, as well as the comparison on length (<>5 vs <5).
Try this:
SELECT
CASE
WHEN LEN(ID) < 6 THEN LEFT(ID + Code),6)
ELSE ID
END AS Code
FROM tblID
ORDER BY ID DESC;
Try this:
SELECT
CASE
WHEN LEN(ID) <> 6 THEN SUBSTRING(ID, 1, 6-LEN(Code)) + Code
ELSE ID
END as Code
FROM tblID
ORDER BY ID DESC;
I am working in Teradata with some descriptive data that needs to be transformed from a gerneric varchar(60) into the different field lengths based on the type of data element and the attribute value. So I need to take whatever is in the Varchar(60) and based on field 'ABCD' act on field 'XYZ'. In this case XYZ is a varchar(3). To do this I am using CASE logic within my select. What I want to do is
eliminate all occurances of non alphabet/numeric data. All I want left are upper case Alpha chars and numbers.
In this case "Where abcd = 'GROUP' then xyz should come out as a '000', '002', 'A', 'C'
eliminate extra padding
Shift everything Right
abcd xyz
1 GROUP NULL
2 GROUP $
3 GROUP 000000000000000000000000000000000000000000000000000000000000
4 GROUP 000000000000000000000000000000000000000000000000000000000002
5 GROUP A
6 GROUP C
7 GROUP r
To do this I have tried TRIM and SUBSTR amongst several other things that did not work. I have pasted what I have working now, but I am not reliably working through the data within the select. I am really looking for some options on how to better work with strings in Teradata. I have been working out of the "SQL Functions, Operators, Expressions and Predicates" online PDF. Is there a better reference. We are on TD 13
SELECT abcd
, CASE
-- xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
WHEN abcd= 'GROUP'
THEN(
CASE
WHEN SUBSTR(tx.abcd,60, 4) = 0
THEN (
SUBSTR(tx.abcd,60, 3)
)
ELSE
TRIM (TRAILING FROM tx.abcd)
END
)
END AS abcd
FROM db.descr tx
WHERE tx.abcd IS IN ( 'GROUP')
The end result should look like this
abcd xyz
1 GROUP 000
2 GROUP 002
3 GROUP A
4 GROUP C
I will have to deal with approx 60 different "abcd" types, but they should all conform to the type of data I am currently seeing.. ie.. mixed case, non numeric, non alphabet, padded, etc..
I know there is a better way, but I have come in several circles trying to figure this out over the weekend and need a little push in the right direction.
Thanks in advance,
Pat
The SQL below uses the CHARACTER_LENGTH function to first determine if there is a need to perform what amounts to a RIGHT(tx.xyz, 3) using the native functions in Teradata 13.x. I think this may accomplish what you are looking to do. I hope I have not misinterpreted your explanation:
SELECT CASE WHEN tx.abcd = 'GROUP'
AND CHARACTER_LENGTH(TRIM(BOTH FROM tx.xyz) > 3
THEN SUBSTRING(tx.xyz FROM (CHARACTER_LENGTH(TRIM(BOTH FROM tx.xyz)) - 3))
ELSE tx.abcd
END
FROM db.descr tx;
EDIT: Fixed parenthesis in SUBSTRING
I Have an SQL query giving me X results, I want the query output to have a coulmn called
count making the query somthing like this:
count id section
1 15 7
2 3 2
3 54 1
4 7 4
How can I make this happen?
So in your example, "count" is the derived sequence number? I don't see what pattern is used to determine the count must be 1 for id=15 and 2 for id=3.
count id section
1 15 7
2 3 2
3 54 1
4 7 4
If id contained unique values, and you order by id you could have this:
count id section
1 3 2
2 7 4
3 15 7
4 54 1
Looks to me like mikeY's DSum approach could work. Or you could use a different approach to a ranking query as Allen Browne described at this page
Edit: You could use DCount instead of DSum. I don't know how the speed would compare between the two, but DCount avoids creating a field in the table simply to store a 1 for each row.
DCount("*","YourTableName","id<=" & [id]) AS counter
Whether you go with DCount or DSum, the counter values can include duplicates if the id values are not unique. If id is a primary key, no worries.
I frankly don't understand what it is you want, but if all you want is a sequence number displayed on your form, you can use a control bound to the form's CurrentRecord property. A control with the ControlSource =CurrentRecord will have an always-accurate "record number" that is in sequence, and that will update when the form's Recordsource changes (which may or may not be desirable).
You can then use that number to navigate around the form, if you like.
But this may not be anything like what you're looking for -- I simply can't tell from the question you've posted and the "clarifications" in comments.
The only trick I have seen is if you have a sequential id field, you can create a new field in which the value for each record is 1. Then you do a running sum of that field.
Add to your query
DSum("[New field with 1 in it]","[Table Name]","[ID field]<=" & [ID Field])
as counterthing
That should produce a sequential count in Access which is what I think you want.
HTH.
(Stolen from Rob Mills here:
http://www.access-programmers.co.uk/forums/showthread.php?p=160386)
Alright, I guess this comes close enough to constitute an answer: the following link specifies two approaches: http://www.techrepublic.com/blog/microsoft-office/an-access-query-that-returns-every-nth-record/
The first approach assumes that you have an ID value and uses DCount (similar to #mikeY's solution).
The second approach assumes you're OK creating a VBA function that will run once for EACH record in the recordset, and will need to be manually reset (with some VBA) every time you want to run the count - because it uses a "static" value to run its counter.
As long as you have reasonable numbers (hundreds, not thousands) or records, the second approach looks like the easiest/most powerful to me.
This function can be called from each record if available from a module.
Example: incrementingCounterTimeFlaged(10,[anyField]) should provide your query rows an int incrementing from 0.
'provides incrementing int values 0 to n
'resets to 0 some seconds after first call
Function incrementingCounterTimeFlaged(resetAfterSeconds As Integer,anyfield as variant) As Integer
Static resetAt As Date
Static i As Integer
'if reset date < now() set the flag and return 0
If DateDiff("s", resetAt, Now()) > 0 Then
resetAt = DateAdd("s", resetAfterSeconds, Now())
i = 0
incrementingCounterTimeFlaged = i
'if reset date > now increments and returns
Else
i = i + 1
incrementingCounterTimeFlaged = i
End If
End Function
autoincrement in SQL
SELECT (Select COUNT(*) FROM table A where A.id<=b.id),B.id,B.Section FROM table AS B ORDER BY B.ID Asc
You can use ROW_NUMBER() which is in SQL Server 2008
SELECT ROW_NUMBER() OVER (ORDER By ID DESC) RowNum,
ID,
Section
FROM myTable
Then RowNum displays sequence of row numbers.
I have a table of vehicles with registration numbers, and want to select a subset of them that are between some user-supplied 'from' and 'to' values.
So lets say the table looks like this:
id reg_num
1 DD1111
2 DD1112
3 DE2245
4 EE5678
5 EF6547
The SQL I have so far looks like this:
select *
from vehicles
where reg_num >= 'DD' -- this value is user supplied
and reg_num <= 'DE' -- and so is this one
Which should (by my thinking) return:
1 DD1111
2 DD1112
3 DE2245
But instead, only returns:
1 DD1111
2 DD1112
I imagine that SQL server sees 'DE2245' as greater than 'DE', and so excludes the row.
My question: How do I get SQL server to include all rows that start with 'DE'?
You have to add 'zzzz's at the end as many as necessary to match your column width definition.
select * from vehicles
where reg_num >= 'DD' and reg_num <= 'DE' + 'ZZZZZZZZZZZZ'
where reg_num >= #userValueFrom
and left(reg_num,char_length(#userValueTo) <= #userValueTo
but please note that this where does not utilize any index because of a function on the column in SARG.
If the format is guaranteed, you can simply do:
SELECT *
FROM vehicles
WHERE LEFT(reg_num, 2) BETWEEN 'DD' AND 'DE'
But again, this is supposedly not SARGable - which always baffles me, because surely an index on reg_num can be used...
DE2245 is not less than DE. To make it more clear, DE2245 is less than DE3