Using Aggregate Function in a Join - plsql

I am trying to use an aggregate function, COUNT, in a join. However, there seems to be a problem with what I've written, and I keep getting error messages. Here is what I have so far:
select a.firstname, a.lastname, iddonor, count(idpledge)
from dd_donor a inner join dd_pledge b
using(iddonor)
group by (iddonor);
I want to count the number of pledges made by each donor, and I want to group it by the donor's ID. How can I do this?

You need to add the other non-summary fields to the GROUP BY:
select a.firstname, a.lastname, iddonor, count(idpledge)
from dd_donor a inner join dd_pledge b
using(iddonor)
group by (FIRSTNAME, LASTNAME, iddonor)
SQLFiddle here
Share and enjoy.

Related

SQLite - Select by column value count

How do I select by column value count? In SQL query it would be something like this: select * from band inner join bandsinger on band.id = bandsinger.bandid inner join singer on singer.id = bandsinger.singerid group by band.id having count(singerid=6)>0 and count(singerid=4)>0 if SQLite function count() could accept a function as a parameter, but it doesn't.
The point is to select two bands, where two singers with known IDs sing.
I found the solution. In this case a query should be: select * from band inner join bandsinger on band.id = bandsinger.bandid inner join singer on singer.id = bandsinger.singerid where dinger.id = 6 or singer.id=4 group by band.id having count(*)=x where x is number of given IDs to count.

SQLite join doesnt show nothing

I have this sql statement
SELECT a.*, c.*
FROM ALUMNOS AS a
JOIN calif AS c
where a.curp=c.curp
If I select individually the data on each table - it is showed, but when I do the join - the results are 0. Can you help me, or you need more information?Thanks.
Edit: Already sollved, the data it's shown when both tables have at least 1 column with the same id.
Edit 2: I didn't thougt that the statement doesn't show nothing if the joined column has no data. My bad.
Your query is incorrect. What you want is an implicit join
SELECT a.*, c.*
FROM ALUMNOS AS a, calif AS c
where a.curp=c.curp
you can also rewrite it as explicit join:
SELECT a.*, c.*
FROM ALUMNOS JOIN CALIF USING (curp)

SQL Query assistance - Looping through data query

I have two tables. Config and Data. Config table has info to define what I call "Predefined Points". The columns are configId, machineId, iotype, ioid, subfield and predeftype. I have a second table that contains all the data for all the items in the config table linked by configId. Data table contains configId, timestamp, value.
I am trying to return each row from the config table with 2 new columns in the result which would be min timestamp of this particular predefined point and max timestamp of this particular predefined point.
Pseudocode would be
select a.*, min(b.timestamp), max(b.timestamp) from TrendConfig a join TrendData b on a.configId = b.configId where configId = (select configId from TrendConfig)
Where the subquery would return multiple values.
Any idea how to formulate this?
Try an inner join:
select a.*, b.min(timestamp), b.max(timestamp)
from config a
inner join data b
on a.configId = b.configID
I was able to find an answer using: Why can't you mix Aggregate values and Non-Aggregate values in a single SELECT?
The solution was indeed GROUP BY as CL mentioned above.
select a.*, min(b.timestamp), max(b.timestamp) from TrendConfig a join TrendData b on a.configId = b.configId group by a.configId

find count of distinct values in a column

Hi all am trying to build a sql query to display some information on a dashboard.
I have a table in which i store my sales data.My query needs to find total sales in last 7 days,average and group it based on region(which is present in user table.) .I created a temp table to get the item sales.DashBoard_Items table contains particular item that needs to be shown on dashboard.Now my problem is i need to get the store count of each region to find average sales.Can some one please help
Declare #TableTest
table(itemid int,itemname varchar(100),itemdescription varchar(100),id int,itemidd int,userid int,orderdate varchar(40),qty int)
insert into #TableTest
select * from DashBoard_Items join
SalesQTY on SalesQTY.OrderDate>= CONVERT(varchar(10) , DATEADD(DAY,-7,GETDATE()),126)
and OOS_DashBoard_CoreItems.itemid=SalesQTY.itemid
select distinct t.userid,u.region from #TableTest t join users u on t.userid=u.userid and region is not null
above select query returns
how can i get region count from the above select query
region count
5 - SUN WEST 2
2 - LONG ISLAND 3
You need to group by region and then use cont(*)
SELECT region, count(*)
FROM #TableTest
GROUP BY region;
Please try:
SELECT
Region,
COUNT(*) AS [Count]
FROM YourTable
GROUP BY Region
OR
SELECT
DISTINCT Region,
COUNT(*) OVER (PARTITION BY Region) AS [Count]
FROM YourTable
SELECT u.region, COUNT(*)
FROM #TableTest t JOIN users u ON t.userid=u.userid AND u.region IS NOT NULL
GROUP BY u.region
try
SELECT region, count( * )
FROM mytable
GROUP BY region

Advanced SQLite Update table query

I am trying to update Table B of a database looking like this:
Table A:
id, amount, date, b_id
1,200,6/31/2012,1
2,300,6/31/2012,1
3,400,6/29/2012,2
4,200,6/31/2012,1
5,200,6/31/2012,2
6,200,6/31/2012,1
7,200,6/31/2012,2
8,200,6/31/2012,2
Table B:
id, b_amount, b_date
1,0,0
2,0,0
3,0,0
Now with this query I get all the data I need in one select:
SELECT A.*,B.* FROM A LEFT JOIN B ON B.id=A.b_id WHERE A.b_id>0 GROUP BY B.id
id, amount, date, b_id, id, b_amount, b_date
1,200,6/31/2012,1,1,0,0
3,400,6/29/2012,1,1,0,0
Now, I just want to copy the selected column amount to b_amount and date to b_date
b_amount=amount, b_date=date
resulting in
id, amount, date, b_id, id, b_amount, b_date
1,200,6/31/2012,1,1,200,6/31/2012
3,400,6/29/2012,1,1,400,6/29/2012
I've tried COALESCE() without success.
Does someone experienced have a solution for this?
Solution:
Thanks to the answers below, I managed to come up with this. It is probably not the most efficient way but it is fine for a one time only update. This will insert for you the first corresponding entry of each group.
REPLACE INTO A SELECT id, amount, date FROM
(SELECT A.id, A.amount, B.id as Bid FROM A INNER JOIN B ON (B.id=A.B_id)
ORDER BY A.id DESC)
GROUP BY Bid;
So what you are looking for seems to be a JOIN inside of an UPDATE query. In mySQL you would use
UPDATE B INNER JOIN A ON B.id=A.b_id SET B.amount=A.amount, B.date=A.date;
but this is not supported by sqlite as this probably related question points out. However, there is a workaround using REPLACE:
REPLACE INTO B
SELECT B.id, A.amount, A.date FROM A
LEFT JOIN B ON B.id=A.b_id
WHERE A.b_id>0 GROUP BY B.id;
The query will simply fill in the values of table B for all columns which should keep their state and fill in the values of table A for the copied values. Make sure the order of the columns in the SELECT statement meet your column order of table B and all columns are mentioned or you will loose these field's data. This is probably dangerous for future changes on table B. So keep in mind to change the column order/presence of this query when changing table B.
Something a bit off topic, because you did not ask for that: A.b_id is obviously a foreign key to B.id. It seems you are using the value 0 for the foreign key to express that there is no corresponding entry in B. (Inferred from your SELECT with WHERE A.b_id>0.) You should consider using the null value for that. When you are using INNER JOIN then instead of LEFT JOIN you can drop the WHERE clause entirely. The DBS will then sort out all unsatisfied relations.
WARNING Some RDBMS will return 2 rows as you show above. Others will return the Cartesian product of the rows i.e. A rows times B rows.
One tricky method is to generate SQL that is then executed
SELECT "update B set b.b_amount = ", a.amount, ", b.b_date = ", a.date,
" where b.id = ", a.b_id
FROM A LEFT JOIN B ON B.id=A.b_id WHERE A.b_id>0 GROUP BY B.id
Now add the batch terminator and execute this SQL. The query result should look like this
update B set b.b_amount = 200, b.b_date = 6/31/2012 where b.id = 1
update B set b.b_amount = 400, b.b_date = 6/29/2012 where b.id = 3
NOTE: Some RDBMS will handle dates differently. Some require quotes.

Resources