How to select multiple count(*) values then group by a specific column - sql

I've used SQL for a while but wouldn't say I'm at an advanced level. I've tinkered with trying to figure this out myself to no avail.
I have two tables - Transaction and TransactionType:
| **TransactionID** | **Name** | **TransactionTypeID** |
| 1 | Tom | 1 |
| 2 | Jim | 1 |
| 3 | Mo | 2 |
| 4 | Tom | 3 |
| 5 | Sarah | 4 |
| 6 | Tom | 1 |
| 7 | Sarah | 1 |
| **TransactionTypeID** | **TransactionType** |
| 1 | A |
| 2 | B |
| 3 | C |
| 4 | D |
The Transaction.TransactionTypeID is a Forein Key linked TransactionType.TransactionTypeID field.
Here's what I'd like to achieve:
I'd like a query (this will be a stored procedure) that returns three columns:
Name - the value of the Transaction.Name column.
NumberOfTypeATransactions - the count of the number of all transactions of type 'A' for that person.
NumberOfNonTypeATransactions - the count of the number of all transactions that are NOT of type A for that person, i.e. all other transaction types.
So, using the above data as an example, the result set would be:
| **Name** | **NumberOfTypeATransactions** | **NumberOfNonTypeATransactions** |
| Tom | 2 | 1 |
| Jim | 1 | 0 |
| Mo | 0 | 1 |
| Sarah | 1 | 1 |
I might also need to return the results based on a date period (which will be based on a 'transaction date' column in the Transaction table but I haven't finalized this requirement yet.
Any help in how I can achieve this would be much appreciated. Apologies of the layout of the tables is a bit odd - haven't worked out how to format them properly yet.

This is just conditional aggregation with a join:
select t.name,
sum(case when tt.TransactionType = 'A' then 1 else 0 end) as num_As,
sum(case when tt.TransactionType <> 'A' then 1 else 0 end) as num_notAs
from transaction t join
transactiontype tt
on tt.TransactionTypeID = t.TransactionTypeID
group by t.name;

Related

How to write a sql script that cursors through a table and inserts into a different table

I am new to sql server i have the following table structure that contains more than a thousand rows.
But for example purposes this is what it would look like
Table Import
+------+---------+------------+------------+------------+------------+------------+
| Name | Code | SocksTotal | GlovesTotal| JeansTotal | ShirtsTotal| shoesTotal |
+------+---------+------------+------------+------------+------------+------------+
| OT | 45612 | 2 | 1 | 0 | 1 | 4 |
| OT | 1234 | 0 | 1 | 0 | 0 | 0 |
| US | 45896| 0 | 0 | 0 | 0 | 0 |
+------+---------+------------+------------+------------+------------+------------+
and a second table called Items follows
+------+---------+
| ID | Item |
+------+---------+
| 1 | socks |
| 2 | Gloves|
| 3 | Jeans |
| 4 | Shirts|
| 5 | shoes |
+------+---------+
from the above tables i need to write a script that would be inserted into a different table called ImportItems_Summary.
the expected output is
+------+---------+------------+------------+
| Id | Code | Items_id |Import_total|
+------+---------+------------+------------+
| 1 | 45612 | 1 | 2 |
| 2 | 45612 | 2 | 1 |
| 3 | 45612 | 4 | 1 |
| 4 | 45612 | 5 | 4 |
| 5 | 1234 | 2 | 1 |
+------+---------+------------+------------+
as you can see here that code 45612 now has 4 entries into the ImportItems_summary table where the items is not equal to 0 and the Items_id is linked to the Items table ID column.
How can i achieve the above output?.. I read up and saw a cursor might help but i am not sure how to implement this
One method uses cross apply to unpivot the columns of the unnormalized table to rows, then brings the items table with a join, and finally inserts in the target table:
insert into ImportItems_Summary (code, items_id, import_total)
select im.code, it.items_id, x.import_total
from import im
cross apply (values
('socks', sockstotal),
('gloves', glovestotal),
('jeans', jeanstotal),
('shirts', shirtstotal),
('shoes', shoestotal)
) x(item, import_total)
inner join items it on it.item = x.item

Oracle SQL unpivot and keep rows with null values [duplicate]

This question already has an answer here:
oracle - querying NULL values in unpivot query
(1 answer)
Closed 2 years ago.
I'm currently doing an unpivot for a Oracle Data Source (v.12.2) like this:
SELECT *
FROM some_table
UNPIVOT (
(X,Y,Val)
FOR SITE
IN (
(SITE1_X, SITE1_Y, SITE1_VAL) AS '1',
(SITE2_X, SITE2_Y, SITE2_VAL) AS '2',
(SITE3_X, SITE3_Y, SITE3_VAL) AS '3'
))
This works totally fine so far. There is only one exception - I have another column, let's say extend_info, ... if this column has the value y, there will be only one row of this column and all the site columns will be null. Nevertheless I would like to keep this row and not drop it.
I'm not really sure how to do this or what would be a nice way to do this. Any recommendations?
Example:
Original Table:
ID | SITE1_X | SITE1_Y |SITE1_VAL | SITE2_X | SITE2_Y | SITE2_VAL | ... | extend_info
-------
1 | 0 | 0 | 5 | 1 | 1 | 10 | ... | n
2 | 0 | 0 | 3 | null | null | null | ... | n
3 | null | null | null | null | null | null | ... | y
current output:
ID | SITE | X | Y | VAL | extend_info
-------
1 | 1 | 0 | 0 | 5 | n
2 | 1 | 1 | 1 | 10 | n
3 | 2 | 0 | 0 | 3 | n
desired output:
ID | SITE | X | Y | VAL | extend_info
-------
1 | 1 | 0 | 0 | 5 | n
2 | 1 | 1 | 1 | 10 | n
3 | 2 | 0 | 0 | 3 | n
4 | | | | | y
I don't really care what is in SITE|X|Y|VAL in that case, can be 0 for everything or null.
Bonus question:
If extend_info is y I would like to join another table with this ID. The other table looks like this:
ID | F_ID | X | Y | VAL
-----
1 | 4 | 1 | 1 | 8
2 | 4 | 2 | 2 | 9
and in that case my final output table should look like:
ID | SITE | X | Y | VAL | X_OTHER_TABLE | Y_OTHER_TABLE
-------
1 | 1 | 0 | 0 | 5 |
2 | 1 | 1 | 1 | 10 |
3 | 2 | 0 | 0 | 3 |
4 | | | | 8 | 1 | 1
5 | | | | 9 | 2 | 2
I know... the database structure is super ugly but that is what a vendor provides us and we are trying to create a View to make it easier to perform some data analysis tasks on it.
It doesn't have to look 1:1 like my final example - but maybe my itention gets clear = I want to have one single table/view with all the information in a single format.
Thanks for any help!
I would recommend a lateral join:
SELECT s.id, u.*
FROM some_table s CROSS JOIN LATERAL
(SELECT s.SITE1_X as SITE_X, s.SITE1_Y as SITE_Y, s.SITE1_VAL as SITE_VAL FROM DUAL UNION ALL
SELECT s.SITE2_X, s.SITE2_Y, s.SITE2_VAL FROM DUAL UNION ALL
SELECT s.SITE3_X, s.SITE3_Y, s.SITE3_VAL FROM DUAL
) u;
You can just join additional tables to this as you like.

Create New Columns from Row Values then Group By

My current table looks like this:
+-------+------+
| Level | Team |
+-------+------+
| 1 | 1 |
| 2 | 1 |
| 2 | 1 |
| 3 | 2 |
| 3 | 2 |
| 3 | 2 |
+-------+------+
I want to group by level and know the count of level for both teams. I can easily get the count of a single team by using the following:
SELECT Level, Count(Team)
FROM table
WHERE Team = 1
GROUP BY Level
SORT BY Level;
+-------+-------------+
| Level | Team1_Count |
+-------+-------------+
| 1 | 1 |
| 2 | 2 |
| 3 | 0 |
+-------+-------------+
However, the end result I want is below:
+-------+-------------+-------------+
| Level | Team1_Count | Team2_Count |
+-------+-------------+-------------+
| 1 | 1 | 0 |
| 2 | 2 | 0 |
| 3 | 0 | 3 |
+-------+-------------+-------------+
Removing the WHERE clause gives the total per Level but does not split it into Teams. How do I make it so both of these new columns are created and show the counts per Level?
Try the following using case expression with sum. Here is the demo.
select
level,
sum(case when team = 1 then 1 else 0 end) as Team1_count,
sum(case when team = 2 then 1 else 0 end) as Team2_count
from table
group by
level
order by
level
output
| level | Team1_count | Team2_count |
| ----- | ----------- | ----------- |
| 1 | 1 | 0 |
| 2 | 2 | 0 |
| 3 | 0 | 3 |
if you are using postgreSQL then you can use filter with count as following
select
level,
count(*) filter (where team = 1) as Team1_count,
count(*) filter (where team = 2) as Team2_count
from tableA
group by
level
order by
level

How to select if similar field count is the maximum in the table?

I want to select from a table if row counts of similar filed is maximum depends on other columns.
As example
| user_id | team_id | isOk |
| 1 | 1 | 1 |
| 2 | 1 | 1 |
| 3 | 1 | 1 |
| 4 | 1 | 1 |
| 5 | 2 | 1 |
| 6 | 2 | 1 |
| 7 | 2 | 1 |
| 8 | 3 | 1 |
| 9 | 3 | 1 |
| 10 | 3 | 1 |
| 11 | 3 | 0 |
So i want to select team 1 and 2 because they all have 1 value at isOk Column,
i tried to use this query
SELECT Team
FROM _Table1
WHERE isOk= 1
GROUP BY Team
HAVING COUNT(*) > 3
But still i have to define a row count which can be maximum or not.
Thanks in advance.
Is this what you are looking for?
select team
from _table1
group by team
having min(isOk) = 1;

SQL compare multiple rows or partitions to find matches

The database I'm working on is DB2 and I have a problem similar to the following scenario:
Table Structure
-------------------------------
| Teacher Seating Arrangement |
-------------------------------
| PK | seat_argmt_id |
| | teacher_id |
-------------------------------
-----------------------------
| Seating Arrangement |
-----------------------------
|PK FK | seat_argmt_id |
|PK | Row_num |
|PK | seat_num |
|PK | child_name |
-----------------------------
Table Data
------------------------------
| Teacher Seating Arrangement|
------------------------------
| seat_argmt_id | teacher_id |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
------------------------------
---------------------------------------------------
| Seating Arrangement |
---------------------------------------------------
| seat_argmt_id | row_num | seat_num | child_name |
| 1 | 1 | 1 | Abe |
| 1 | 1 | 2 | Bob |
| 1 | 1 | 3 | Cat |
| | | | |
| 2 | 1 | 1 | Abe |
| 2 | 1 | 2 | Bob |
| 2 | 1 | 3 | Cat |
| | | | |
| 3 | 1 | 1 | Abe |
| 3 | 1 | 2 | Cat |
| 3 | 1 | 3 | Bob |
| | | | |
| 4 | 1 | 1 | Abe |
| 4 | 1 | 2 | Bob |
| 4 | 1 | 3 | Cat |
| 4 | 2 | 2 | Dan |
---------------------------------------------------
I want to see where there are duplicate seating arrangements for a teacher. And by duplicates I mean where the row_num, seat_num, and child_name are the same among different seat_argmt_id for one teacher_id. So with the data provided above, only seat id 1 and 2 are what I would want to pull back, as they are duplicates on everything but the seat id. If all the children on the 2nd table are exact (sans the primary & foreign key, which is seat_argmt_id in this case), I want to see that.
My initial thought was to do a count(*) group by row#, seat#, and child. Everything with a count of > 1 would mean it's a dupe and = 1 would mean it's unique. That logic only works if you are comparing single rows though. I need to compare multiple rows. I cannot figure out a way to do it via SQL. The solution I have involves going outside of SQL and works (probably). I'm just wondering if there is a way to do it in DB2.
Does this do what you want?
select d.teacher_id, sa.row_num, sa.seat_num, sa.child_name
from seatingarrangement sa join
data d
on sa.seat_argmt_id = d.seat_argmt_id
group by d.teacher_id, sa.row_num, sa.seat_num, sa.child_name
having count(*) > 1;
EDIT:
If you want to find two arrangements that are the same:
select sa1.seat_argmt_id, sa2.seat_argmt_id
from seatingarrangement sa1 join
seatingarrangement sa2
on sa1.seat_argmt_id < sa2.seat_argmt_id and
sa1.row_num = sa2.row_num and
sa1.seat_num = sa2.seat_num and
sa1.child_name = sa2.child_name
group by sa1.seat_argmt_id, sa2.seat_argmt_id
having count(*) = (select count(*) from seatingarrangement sa where sa.seat_argmt_id = sa1.seat_argmt_id) and
count(*) = (select count(*) from seatingarrangement sa where sa.seat_argmt_id = sa2.seat_argmt_id);
This finds the matches between two arrangements and then verifies that the counts are correct.