SQL-change the text of a column when a condition is meet - sql

I am just learning DB Syntax so im sorry if this is not a relevant question.
I'm trying to change the text of a column when a condition is meet. I have tried many things but have not achieved anything.
|---------------------|------------------|------------------|
| Some PK | Some FK | someDatetime |
|---------------------|------------------|------------------|
| 12 | 34 | 1900/01/01 |
|---------------------|------------------|------------------|
| 13 | 54 | 2018/05/32 |
|---------------------|------------------|------------------|
| 15 | 60 | 2000/01/01 |
|------------------------------------------------------------
What i Need is to display this same table, but when the date is lower from 2018(I know that can be achieved with a where), the query brings this back:
|---------------------|------------------|------------------|
| Some PK | Some FK | someDatetime |
|---------------------|------------------|------------------|
| 12 | 34 | ---------- |
| | | or My own string|
|---------------------|------------------|------------------|
| 13 | 54 | 2018/05/32 |
|---------------------|------------------|------------------|
| 15 | 60 | ---------- |
| | | or My own string |
|------------------------------------------------------------

You could use the YEAR function to check the date:
SELECT
PK,
FK,
CASE WHEN YEAR(someDatetime) < 2018
THEN 'my own string'
ELSE CONVERT(VARCHAR, someDatetime, 120) END AS someDatetime
FROM yourTable;
Note that if you want to generate a text column with your message, in the case the year be earlier than 2018, then the entire CASE expression should generate text. So, we can use CONVERT on the datetime column to generate a text version of the date.

use case when and Year function for converting date to year
select some_PK,some_FK,
case when Year(someDatetime)<'2018' then 'My own string' else someDatetime
end as someDatetime
from yourtable

Why wouldn't you just do:
select . . . ,
(case when someDateTime < '2018-01-01'
then 'my own string'
else convert(varchar(255), someDateTime) -- might want to include a format
end)
No function is needed for the date comparison, just a date comparison.

Related

SQL GROUPING with conditional

I am sure this is easy to accomplish but after spending the whole day trying I had to give up and ask for your help.
I have a table that looks like this
| PatientID | VisitId | DateOfVisit | FollowUp(Y/N) | FollowUpWks |
----------------------------------------------------------------------
| 123456789 | 2222222 | 20180802 | Y | 2 |
| 123456789 | 3333333 | 20180902 | Y | 4 |
| 234453656 | 4443232 | 20180506 | N | NULL |
| 455344243 | 2446364 | 20180618 | Y | 12 |
----------------------------------------------------------------------
Basically I have a list of PatientIDs, each patient can have multiple visits (VisitID and DateOfVisit). FollowUp(Y/N) specifies whether the patients has to be seen again and in how many weeks (FollowUpWks).
Now, what I need is a query that extracts PatientsID, DateOfVisit (the most recent one and only if FollowUp is YES) and the FollowUpWks field.
Final result should look like this
| PatientID | VisitId | DateOfVisit | FollowUp(Y/N) | FollowUpWks |
----------------------------------------------------------------------
| 123456789 | 3333333 | 20180902 | Y | 4 |
| 455344243 | 2446364 | 20180618 | Y | 12 |
----------------------------------------------------------------------
The closest I could get was with this code
SELECT PatientID,
Max(DateOfVisit) AS LastVisit
FROM mytable
WHERE FollowUp = True
GROUP BY PatientID;
The problem is that when I try adding the FollowUpWks field to the SELECT I get the following error: "The query does not include the specified expression as part of an aggregate function." However, if I add FollowUpWks to the GROUP BY statement than I get all visits, not just the most recent ones.
You need to match back to the most recent visit. One method uses a correlated subquery:
SELECT t.*
FROM mytable as t
WHERE t.FollowUp = True AND
t.DateOfVisit = (SELECT MAX(t2.DateOfVisit)
FROM mytable as t2
WHERE t2.PatientID = t.PatientID
);

Access 2016 & SQL: Totaling two columns, then subtracting them

Say I have a MoneyIN and a MoneyOUT column. I wish to total these entire columns up so I have a sum of each, then I wish to subtract the total of the MoneyOUT column from the total of the MoneyIN column. I also want to display a DateOF column and possibly a description (I think I can do that by myself).
This would be the original database where I get my information from:
+-------------+------------------+---------+----------+-----------+
| Location ID | Location Address | Date Of | Money In | Money Out |
+-------------+------------------+---------+----------+-----------+
| 1 | blah | date | 10.00 | 0.00 |
| 2 | blah | date | 2,027.10 | 27.10 |
| 2 | blah | date | 0.00 | 2000.00 |
| 1 | blah | date | 0.00 | 10.00 |
| 3 | blah | date | 5000.00 | 0.00 |
+-------------+------------------+---------+----------+-----------+
I would like to be able to type in a location ID and then have results show up (in this example I type 2 for the location)
+---------+----------+-----------+------+
| Date Of | Money In | Money Out | |
+---------+----------+-----------+------+
| date | 2027.10 | 27.10 | |
| date | 0 | 2000 | |
| Total: | 2027.10 | 2027.10 | 0 |
+---------+----------+-----------+------+
I have tried other solutions (One of which was pointed out below), however, they don't show the sum of each entire column, they simply subtract MoneyOUT from MoneyIN for each row. As of now, I am trying to do this in a query, but if there is a better way, please elaborate.
I am extremely new to SQL and Access, so please make the explanation understandable for a beginner like me. Thanks so much!
This is a table referred to below.
+-------------+-------+----------+-----------+-----------+
| Location ID | Date | Money IN | Money Out | Total Sum |
+-------------+-------+----------+-----------+-----------+
| 1 | date | 300 | 200 | |
| 1 | date | 300 | 200 | |
| 1 | date | 300 | 200 | |
| 1 | total | 900 | 600 | 300 |
+-------------+-------+----------+-----------+-----------+
The following should give you what you want:
SELECT DateOf, MoneyIn, MoneyOut, '' AS TotalSum FROM YourTable
UNION
SELECT 'Total', SUM(MoneyIn) AS SumIn, SUM(MoneyOut) AS SumOut,
SUM(MoneyIn - MoneyOut) AS TotalSum FROM YourTable
Edit:
You do not need to alter very much to achieve what you want. In order to get Access to prompt for a parameter when running a query, you give a name for the parameter in square brackets; Access will then pop-up a window prompting the user for this value. Also this parameter can be used more than once in the query, without Access prompting for it multiple times. So the following should work for you:
SELECT DateOf, MoneyIn, MoneyOut, '' AS TotalSum
FROM YourTable
WHERE LocationID=[Location ID]
UNION
SELECT 'Total', SUM(MoneyIn) AS SumIn, SUM(MoneyOut) AS SumOut,
SUM(MoneyIn - MoneyOut) AS TotalSum FROM YourTable
WHERE LocationID=[Location ID];
However, looking at your table design, I strongly encourage you to change it. You are including the address on every record. If you have three locations, but 100 records, then on average you are unnecessarily repeating each address more than 30 times. The "normal" way to avoid this would be to have a second table, Locations, which would have an ID and an Address field. You then remove address from YourTable, and in its place create a one-to-many relationship between the ID in Locations and the LocationID in YourTable.
It's a little unclear exactly what you expect without sample data, but I think this is what you want:
SELECT DateOf, SUM(MoneyIN) - SUM(MoneyOut)
FROM YourTable
GROUP BY DateOf
This will subtract the summed total of MoneyOut from MoneyIn at each distinct DateOf
Updated Answer
A UNION will let you append a 'Totals' record to the bottom of your result set:
SELECT *
FROM (
SELECT CAST(DateOf as varchar(20)) as DateOf, MoneyIn, MoneyOut, '' as NetMoneyIn
FROM YourTable
UNION
SELECT 'Total:', SUM(MoneyIn), SUM(MoneyOut), SUM(MoneyIN) - SUM(MoneyOut)
FROM YourTable
) A
ORDER BY CASE WHEN DateOf <> 'Total:' THEN 0 ELSE 1 END, DateOf
Some notes.. I used a derived table to ensure that the 'Total' record is last. Also casted DateOf to a string (assuming it is a date), otherwise you will have issues writing the string 'Total:' to that column.

How to check date in postgresql

my table name is tbl1. The fileds are id,name,txdate.
| ID | NAME | TXDATE |
| 1 | RAJ | 1-1-2013 |
| 2 | RAVI | |
| 3 | PRABHU | 25-3-2013 |
| 4 | SAT | |
Now i want to use select query for check txdate < 2-2-2013 in which rows have txdate not empty and the select also retrun which rows have txdate empty.
The Result is like this
| ID | NAME | TXDATE |
| 1 | RAJ | 1-1-2013 |
| 2 | RAVI | |
| 4 | SAT | |
Any feasible solution is there?.
With out using union it is possible?.
Assuming that the TXDATE is of data type DATE then you can use WHERE "TXDATE" < '2013-2-2' OR "TXDATE" IS NULL. Something like:
SELECT *
FROM table1
WHERE "TXDATE" < '2013-2-2'
OR "TXDATE" IS NULL;
See it in action:
SQL Fiddle Demo
I don't now what database your are using and what data type the TXDATE is.
I just tried on my postgreSQL 9.2, with a field "timestamp without time zone".
I have three rows in the table , like:
ac_device_name | ac_last_heartbeat_time
----------------+-------------------------
Nest-Test1 |
Nest-Test3 |
Nest-Test2 | 2013-04-10 15:06:18.287
Then use below statement
select ac_device_name,ac_last_heartbeat_time
from at_device
where ac_last_heartbeat_time<'2013-04-11';
It is ok to return only one record:
ac_device_name | ac_last_heartbeat_time
----------------+-------------------------
Nest-Test2 | 2013-04-10 15:06:18.287
I think you can try statement like:
select * from tbl1 where TXDATE<'2-2-2013' and TXDATE is not NULL
this statement also works in my environment.

SQL query to get dif between dates in select statment

I have a two tables call RFS and RFS_History.
RFS_id | name
--------+--------
12 | xx
14 | yy
15 | zz
figure 1 :RFS table
RFS_id | gate | End | start
--------+-------+--------+-------
12 | aa | 19/02 | 20/03
12 | bb | 30/01 | 12/08
12 | cc | 30/01 | 12/08
13 | aa | 30/01 | 12/08
12 | dd | 30/01 | 12/08
figure 2 :RFS history
My initial query is a select * query to get information where FRSname ='xx'
SELECT * FROM RFS, RFSHistory
WHERE RFSname="xx" And RFShistory.RFS_ID=RFS.RFS_ID
result is:
RFS_id | gate | End | start
--------+-------+--------+-------
12 | aa | 19/02 | 19/01
12 | bb | 12/04 | 12/02
12 | cc | 20/03 | 12/03
12 | dd | 30/09 | 12/08
figure 3
however I want to get a result like bellow format :
RFS_id | gate_aa | gate_bb | gate_cc | gate_dd
----------------------------------------------
12 | 30 days | 60dyas | 8days | 18days
gate_aa is duraion and it gets from start - end date. Please help me to write single query to get this result.
Use datediff() to get date difference and Pivot() to convert row into cloumn
like here in your case gate wise column
Sample Syntax
SELECT DATEDIFF(day,'2008-06-05','2008-08-05') AS DiffDate
You can use the below query for get the difference b/w dates
SELECT RFS.ID,(RFS_HISTORY.end_t-RFS_HISTORY.start_t) AS DiffDate,gate FROM RFS, RFS_HISTORY
WHERE name='aa' And RFS_HISTORY.ID=RFS.ID group by RFS.ID,gate,RFS_HISTORY.end_t,RFS_HISTORY.start_t
I think you want to convert rows into columns on the values. This can be done with the help of pivoting.
SELECT * FROM RFS, RFSHistory
pivot for columname on [values]
I actually forgot the syntax but you can google it

Extract data from largest date

I am having recods as below
---------------------------------------------------------------------
| AcnttNo | Date1 | Balance1 | Date2 | balance3 | date4 | balance4 |
|--------------------------------------------------------------------
| 123 | 50282 | 3456 | 45465 | 56557 | 4556 | 324235 |
| 123 | 56757 | 23434 | 234235 | 344324 | 56476 | 5676 |
| 123 | 435 | 2434 | 2343 | 234545 | 24245 | 2423424 |
---------------------------------------------------------------------
For example:
for each AcnttNo there will be several rows of data for balance and date.
I need to get the balance for largest date.
I'm using PL/SQL developer and an oracle database
If you want the row with the greatest date:
select
*
from
YourTable y
where
greatest(y.date1, y.date2, y.date3) =
(select max(greatest(yx.date1, yx.date2, yx.date3))
from
YourTable yx)
If you do actually need the balance matching the greatest date on that row:
select
greatest(y.date1, y.date2, y.date3) as GreatestDate,
case greatest(y.date1, y.date2, y.date3)
when y.Date1 then
y.balance1
when y.date2 then
y.balance2
when y.date3 then
y.balance3
end as GreatestDateBalance
from
YourTable y
where
greatest(y.date1, y.date2, y.date3) =
(select max(greatest(yx.date1, yx.date2, yx.date3))
from
YourTable yx)
But I think what you really need, is to reconsider your table design. :)
I'm not sure why you've multiple dates / balances in your table, however, the below should get you something interesting that you can work on...
SELECT *
FROM YourTable T
WHERE NOT EXISTS (
SELECT *
FROM YourTable T2
WHERE T2.AcntNo = T.AcntNo
AND T2.Date1 > T.Date1
)