I have a very simple table that has businesses and a column of DisplayBiz = varchar(1) that is either Y or N... I want a script to extract data from the database first all the "Y" and then then all the "N" for a total of ten and I want them ordered by business name..
Is there a way to do this? I am assuming it would be something like this:
SELECT TOP 10 MemberID,
BizName
ORDER BY BizType
but this doesn't take into consideration the DisplayBiz column
Any ideas?
Many thanks..!
You can add more than one column in the ORDER BY clause :
-- ...
ORDER BY DisplayBiz DESC, BizType
Which would put Y rows first, then N rows.
This will get the first 10 alphabetical BizNames that have a 'Y' for DisplayBiz. If there are less than 10, it will start over at A for those with 'N'...
SELECT TOP 10 MemberID, BizName, DisplayBiz
FROM dbo.table
ORDER BY
CASE WHEN DisplayBiz = 'Y' THEN 1 ELSE 2 END,
BizName;
You could also use:
ORDER BY
DisplayBiz DESC,
BizName;
But I prefer the CASE - while more code, you're not taking advantage of the English spelling of Y/N. Seems more proper to be explicit.
Related
Hi it's my first time using SQLite and I am trying to understand if it can count the results it gets and switch conditions to find other results: I am not sure how to write this, so I will use an example:
From a table of players, with the same query I'd like to:
SELECT (x) players WHERE WINS>0 AND WINS<= 3 and
(y) other players WHERE WINS = Null OR WINS=0.
x and y should be integer numbers, but they could vary.
I think I can split the query in 2 queries, but I am worried about the performance since in this way I have to connect to the db twice, and I have to check on the second query that the new IDs have not been selected already in the first one (this should never happen in this example scenario, but might happen with different conditions).
If it's possible to write this all in one single query, that would be much more "simple" and straightforward.
Unfortunately I have to stick to SQLite 3.7.17 and I can't make use of all the updates until now.
mytable is defined like this one:
CREATE TABLE mytable (
ID TEXT PRIMARY KEY,
NAME TEXT,
WINS INTEGER,
LOSSES INTEGER,
NOTES TEXT
);
These are some dummy values:
INSERT INTO mytable(ID, NAME, WINS,LOSSES, NOTES) VALUES
('A001','John','1','0','blue')
('A002','Mark','2','1','blue')
('A003','Hubert','null','null','red')
('A004','Otto','0','0','green')
('A005','Johnson','3','5','red')
('A006','Frank','null','1','green')
As an example result the query should return:
#first part (WINS>0 AND WINS<=3) x = 3
('A005','Johnson','3','5','red')
('A001','John','1','0','blue')
('A002','Mark','2','1','blue')
#second part(WINS=0 OR WINS=Null) y = 2
('A006','Frank','null','1','green')
('A004','Otto','0','0','green')
..so the result should be a table like that
('A005','Johnson','3','5','red')
('A001','John','1','0','blue')
('A002','Mark','2','1','blue')
('A006','Frank','null','1','green')
('A004','Otto','0','0','green')
Thank you for your time and knowledge. :)
Use a CTE where you filter the table for the conditions that you want to apply and with a CASE expression get an integer for the condition that is satisfied for each row.
In another CTE use ROW_NUMBER() window function to rank the rows of each condition.
Finally filter the rows with a CASE expression:
WITH
cond AS (
SELECT *,
CASE
WHEN WINS > 0 AND WINS <= 3 THEN 1
WHEN WINS IS NULL OR WINS = 0 THEN 2 -- or WHEN COALESCE(WINS, 0) = 0 THEN 2
END AS condition
FROM mytable
WHERE condition IN (1, 2)
),
cte AS (SELECT *, ROW_NUMBER() OVER (PARTITION BY condition ORDER BY condition, WINS) rn FROM cond)
SELECT ID, NAME, WINS, LOSSES, NOTES
FROM cte
WHERE rn <= CASE condition
WHEN 1 THEN 3 -- x = 3
WHEN 2 THEN 2 -- y = 2
END
ORDER BY condition, WINS DESC;
See the demo.
I'm still fairly new to SQL. This is a stripped down version of the query I'm trying to run. This query is suppose to find those customers with more than 3 cases and display either the top 1 case or all cases but still show the overall count of cases per customer in each row in addition to all the case numbers.
The TOP 1 subquery approach didn't work but is there another way to get the results I need? Hope that makes sense.
Here's the code:
SELECT t1.StoreID, t1.CustomerID, t2.LastName, t2.FirstName
,COUNT(t1.CaseNo) AS CasesCount
,(SELECT TOP 1 t1.CaseNo)
FROM MainDatabase t1
INNER JOIN CustomerDatabase t2
ON t1.StoreID = t2.StoreID
WHERE t1.SubmittedDate >= '01/01/2017' AND t1.SubmittedDate <= '05/31/2017'
GROUP BY t1.StoreID, t1.CustomerID, t2.LastName, t2.FirstName
HAVING COUNT (t1.CaseNo) >= 3
ORDER BY t1.StoreID, t1.PatronID
I would like it to look something like this, either one row with just the most recent case and detail or several rows showing all details of each case in addition to the store id, customer id, last name, first name, and case count.
Data Example
For these I usually like to make a temp table of aggregates:
DROP TABLE IF EXISTS #tmp;
CREATE TABLE #tmp (
CustomerlD int NOT NULL DEFAULT 0,
case_count int NOT NULL DEFAULT 0,
case_max int NOT NULL DEFAULT 0,
);
INSERT INTO #tmp
(CustomerlD, case_count, case_max)
SELECT CustomerlD, COUNT(tl.CaseNo), MAX(tl.CaseNo)
FROM MainDatabase
GROUP BY CustomerlD;
Then you can join this "tmp" table back to any other table you want to display the number of cases on, or the max case number on. And you can limit it to customers that have more than 3 cases with WHERE case_count > 3
I want to retrieve the 2nd last row result and I have seen this question:
How can I retrieve second last row?
but it uses order by which in my case does not work because the Emp_Number Column contains number of rows and date time stamp that mixes data if I use order by .
The rows 22 and 23 contain the total number of rows (excluding row 21 and 22) and the time and day it got entered respectively.
I used this query which returns the required result 21 but if this number increases it will cause an error.
SELECT TOP 1 *
FROM(
SELECT TOP 2 *
FROM DAT_History
ORDER BY Emp_Number ASC
) t
ORDER BY Emp_Number desc
Is there any way to get the 2nd last row value without using the Order By function?
There is no guarantee that the count will be returned in the one-but-last row, as there is no definite order defined. Even if those records were written in the correct order, the engine is free to return the records in any order, unless you specify an order by clause. But apparently you don't have a column to put in that clause to reproduce the intended order.
I propose these solutions:
1. Return the minimum of those values that represent positive integers
select min(Emp_Number * 1)
from DAT_history
where Emp_Number not regexp '[^0-9]'
See SQL Fiddle
This will obviously fail when the count is larger then the smallest employee number. But seeing the sample data, that would represent a number of records that is maybe not expected...
2. Count the records, ignoring the 2 aggregated records
select count(*)-2
from DAT_history
See SQL Fiddle
3. Relying on correct order without order by
As explained at the start, you cannot rely on the order, but if for some reason you still want to rely on this, you can use a variable to number the rows in a sub query, and then pick out the one that has been attributed the one-but-last number:
select Emp_Number * 1
from (select Emp_Number,
#rn := #rn + 1 rn
from DAT_history,
(select #rn := 0) init
) numbered
where rn = #rn - 1
See SQL Fiddle
The * 1 is added to convert the text to a number data type.
This is not a perfect solution. I am making some assumptions for this. Check if this could work for you.
;WITH cte
AS (SELECT emp_number,
Row_number()
OVER (
ORDER BY emp_number ASC) AS rn
FROM dat_history
WHERE Isdate(emp_number) = 0) --Omit date entries
SELECT emp_number
FROM cte
WHERE rn = 1 -- select the minimum entry, assuming it would be the count and assuming count might not exceed the emp number range of 9888000
I am creating a query of all people who were screened for smoking status and need a count of unique patients. I am pulling from an encounter table, so the patient could have been asked multiple times. In my case when statement I would like to limit the "Then..." result to something like "Then count distinct patients" but it is giving me an error about aggregates not being allowed within an aggregate. If I remove it, it will then not produce a total as I wish and it's telling me I need it in the group by clause, which I do not want. limit is not an option in sql-server to the best of my knowledge
,count(case when soc.tobacco_user_c in (1, 2, 4, 5) and dmw.SMOKING_CESS_CNSL_YN ='y' then enc.PAT_ID **Here is where I want a unique count of patients** end) Compliant
You can combine DISTINCT with a CASE expression.
Example
SELECT
COUNT(DISTINCT CASE WHEN tobacco = 1 THEN PAT_ID ELSE NULL END)
...
;
I've abbreviated your example to make it easier to read. NULLs will not be included in the final count, so there is no need to worry about off by one errors.
case when soc.tobacco_user_c in (1, 2, 4, 5) and dmw.SMOKING_CESS_CNSL_YN ='y' then COUNT(DISTINCT enc.PAT_ID) ELSE 0 end Compliant
I ended up creating two subqueries and then doing a select count distinct on each of the max columns in those queries to limit the results to one
I can't figure out how to select a previous/next row IF the current row does not have any numeric identifiers.
With numeric value I always use 2 queries:
SELECT min(customer_id)
FROM customers
WHERE `customer_id` < 10
GROUP BY customer_status
ORDER BY customer_name ASC
LIMIT 1;
SELECT max(customer_id)
FROM customers
WHERE `customer_id` > 10
GROUP BY customer_status
ORDER BY customer_name DESC
LIMIT 1;
However, I don't have "customer_id" anymore and only "customer_name". When I query the DB and sort by this column, I get:
Ab
Bb
Cc
Dd
Ee
Let's assume my current customer's name is "Cc". I want to be able to select "Bb" and "Dd" from the DB. How? :)
Rows do not have an order, mysql stores the rows in whatever order it wants. Its called clustering. You use LIMIT to grab subsets of a result set. LIMIT 10 says rows 1 to 10. LIMIT 11,20 says rows 11 to 20 and so on. Row 1 corresponding to the order of the row in the result set, since the rows in the tables are more like a "cloud", there is no order until you build a result set with an ORDER BY clause.
i'd select the previous one with...
SELECT MAX(customer_name)
FROM customers
WHERE `customer_name` < 'Cc'
LIMIT 1;
and the next one with...
SELECT MIN(customer_name)
FROM customers
WHERE `customer_name` > 'Cc'
LIMIT 1;
You where nearly there, I think.
Edit: Removed superfluous ORDER BY statements as suggested by Col. Shrapnel.