New SQL dev here. I'm writing a call log application for our Asterisk server. In one table (CDRLogs), I have the call logs from the phone system (src, dst, calldate, duration). In another table I have (Employees) I have empName, empExt, extStartDate extEndDate). I want to join the two together on src and empExt based on who was using a particular ext on the date of the call. One user per extension in a given time frame.
For example, we have had 3 different users sitting at x100 during the month of July. In the Employees table, I have recorded the dates each of these people started and ended their use of that ext. How do I get the join to reflect that?
Thanks in advance
Perhaps something like:
SELECT A.*, B.*
FROM CDRLOGS A
INNER JOIN Employees B
ON A.SRC = B.EmpExt
AND A.CallDate between B.extStartDate and coalesce(B.extEndDate,getdate())
Please replace the * with relevant fields needed
and there may be a better way as a join on a between seems like it would possibly cause some overhead, but I can't think of a better way presently.
Related
Made this account just to ask about this question after being unable to find/expending the local resources I have, so I come to you all.
I'm trying to join two tables - ORDERS and CUSTOMER - as per a question on my assignment
For every order, list the order number and order date along with the customer number, last name, and first name of the customer who placed the order.
So I'm looking for the order number, date, customer number, and the full name of customers.
The code goes as such
SELECT ORDERS.ORDR_ORDER_NUMBER, ORDERS.ORDR_ORDER_DATE, ORDERS.ORDR_CUSTOMER_NUMBER, CUSTOMER.CUST_LAST, CUSTOMER.CUST_FIRST
FROM ORDERS, CUSTOMER
WHERE ORDERS.ORDR_CUSTOMER_NUMBER = CUSTOMER.CUST_CUSTOMER_NUMBER;
I've done this code without the table identifiers, putting quotation marks around ORDERS.ORDR_CUSTOMER_NUMBER, aliases for the two tables, and even putting a space after ORDR_ in both SELECT & WHERE for laughs and nothing's working. All of them keep coming up with the error in the title (ORA-00904), saying [ORDERS.]ORDR_CUSTOMER_NUMBER is the invalid identifier even though it shouldn't be.
Here also are the tables I'm working with, in case that context is needed for help.
Anyway, the query that produces the result you want should take the form:
select
o.ordr_order_number,
o.ordr_order_date,
c.cust_customer_number,
c.cust_last,
c.cust_first
from orders o
join customer c on c.cust_customer_number = o.ordr_customer_number
As you see the query becomes a lot easier to read and write if you use modern join syntax, and if you use table aliases (o and c).
You have to add JOIN or INNER JOIN to your query. Because the data comes from two different tables the WHERE clause will not select both.
FROM Orders INNER JOIN Customers ON Orders.order_Customer_Number = Customer.Cust_Customer_Number
I'm really at a loss for a good title, suggestions are welcome.
I have two tables, one is a table of competitors, the other is a table with three fields
event
competitor
placing - a number representing what place they got at the given event
My goal is, given a set of placings, return all the competitors that achieved that placing at least once at any event.
So, for example, I might want to see all the competitors that placed 1st or 2nd at something.
Not sure how your tables are defined
But could try this sql
SELECT
c.id,
e.event,
e.placing
FROM competitor_table c
LEFT JOIN event_table e
ON e.competitor_id = c.id
WHERE e.placing in (placings_set)
GROUP BY c.id,e.event, e.placing
I just ran into a bug in our code based on the way we're matching data against a Postgres array.
Here's the issue:
In the database, we have a surcharge column that lives in the appointment table where the ids of all surcharges attached to an appointment are stored. In some cases, a surcharge may be added twice and therefore would look like {1,1} in the database.
I was using a simple query like the following to retrieve the surcharge data associated with the surcharges that have been attached to the appointment:
SELECT s.* FROM surcharge s, appointment a WHERE s.id = ANY(a.surcharges);
Unfortunately, I didn't test this case where more than one of the same surcharge exists. The result is that only 1 record is being returned rather than the 2 I really need.
To clarify, an example would be an appointment with appointment.surcharges = {1,1}, I'd actually want to be able to retrieve the record from surcharges TWICE because it has two surcharges associated with it. I then use those records to create billing-related transactions associated with the appointment.
All that said, is there a simple way to allow a query to return the duplicates that I need?
I can handle this situation in code, but it would be great to run a simple query to handle this situation.
I'm running Postgres 9.5.
Thank you in advance!
I think a plain inner join to an unnested table of surcharges should give you what you want:
SELECT s.*
FROM surcharge s
INNER JOIN
(
SELECT UNNEST(surcharges) AS surcharges
FROM appointment
) a
ON s.id = a.surcharges;
I am not even sure if I am asking this question correctly. Algorithmically I know what I want to do, but don't know the appropriate syntax in SQL.
I have created a table that contains total online session times by customer number, IP, session start time, and total session length. Here is an example of what this table looks like(ip and CustNo is masked, also not sure how to make tables so excuse the weirdness):
CustNo minDate maxDate ClientIp timeDiff
123456 2017-11-14-02:39:27.093 2017-11-14-02:39:59.213 1.1.1.1 0.000372
I then create another table looking for a specific type of activity and want to know how long this specific user has used that IP for before this specific activity. The second table contains each activity as a separate row, customerID, IP and a timestamp.
Up to here no issue and the tables look fine.
I now need to write the part that will look into the first table based on customer ID and IP, then sum all usage of that IP for that customer as long as session min start time is less than the activity time but I have no idea how to do this. Here is the current function (not working obviously). I am doing a left join because it is possible this will be a new IP and it may not be in the first table.
SELECT
*,
SUM(##finalSessionSums.timeDiff)
FROM
##allTransfersToDiffReceip
LEFT JOIN
##finalSessionSums ON ##allTransfersToDiffReceip.CustNo = ##finalSessionSums.CustNo
AND ##allTransfersToDiffReceip.ClientIp = ##finalSessionSums.ClientIp
AND ##allTransfersToDiffReceip.[DateTime] < ##finalSessionSums.minDate
I get an aggregate function error here but I don't know how to approach this at all.
You have a SELECT * (return all columns) and an aggregate function (In this case SUM). Whenever you combine specific columns for return alongside aggregate, summarised values you need to stipulate each column specified in the SELECT clause in the GROUP BY clause. For example
SELECT
A, B, SUM(C) as CSum
FROM
Table
GROUP BY
A, B
In cause of the few information, I can't provide a perfect solution, but I'll give it a try:
First, like Alan mentioned, you have to select only columns that you need for your aggregate-function, which is CustomerNo and Ip. To get the sums of the query, you have to group it like this:
SELECT sum(s.timeDiff) as Sum, s.custNo, s.Ip
FROM ##finalSessionSums s
INNER JOIN ##allTransfersToDiffReceip a on a.CustNo = s.CustNo
AND a.ClientIp = s.ClientIp
AND a.[DateTime] < s.minDate
GROUP BY s.custNo, s.Ip;
Where are Cartesian Joins used in real life?
Can some one please give examples of such a Join in any SQL database.
just random example. you have a table of cities: Id, Lat, Lon, Name. You want to show user table of distances from one city to another. You will write something like
SELECT c1.Name, c2.Name, SQRT( (c1.Lat - c2.Lat) * (c1.Lat - c2.Lat) + (c1.Lon - c2.Lon)*(c1.Lon - c2.Lon))
FROM City c1, c2
Here are two examples:
To create multiple copies of an invoice or other document you can populate a temporary table with names of the copies, then cartesian join that table to the actual invoice records. The result set will contain one record for each copy of the invoice, including the "name" of the copy to print in a bar at the top or bottom of the page or as a watermark. Using this technique the program can provide the user with checkboxes letting them choose what copies to print, or even allow them to print "special copies" in which the user inputs the copy name.
CREATE TEMP TABLE tDocCopies (CopyName TEXT(20))
INSERT INTO tDocCopies (CopyName) VALUES ('Customer Copy')
INSERT INTO tDocCopies (CopyName) VALUES ('Office Copy')
...
INSERT INTO tDocCopies (CopyName) VALUES ('File Copy')
SELECT * FROM InvoiceInfo, tDocCopies WHERE InvoiceDate = TODAY()
To create a calendar matrix, with one record per person per day, cartesian join the people table to another table containing all days in a week, month, or year.
SELECT People.PeopleID, People.Name, CalDates.CalDate
FROM People, CalDates
I've noticed this being done to try to deliberately slow down the system either to perform a stress test or an excuse for missing development deliverables.
Usually, to generate a superset for the reports.
In PosgreSQL:
SELECT COALESCE(SUM(sales), 0)
FROM generate_series(1, 12) month
CROSS JOIN
department d
LEFT JOIN
sales s
ON s.department = d.id
AND s.month = month
GROUP BY
d.id, month
This is the only time in my life that I've found a legitimate use for a Cartesian product.
At the last company I worked at, there was a report that was requested on a quarterly basis to determine what FAQs were used at each geographic region for a national website we worked on.
Our database described geographic regions (markets) by a tuple (4, x), where 4 represented a level number in a hierarchy, and x represented a unique marketId.
Each FAQ is identified by an FaqId, and each association to an FAQ is defined by the composite key marketId tuple and FaqId. The associations are set through an admin application, but given that there are 1000 FAQs in the system and 120 markets, it was a hassle to set initial associations whenever a new FAQ was created. So, we created a default market selection, and overrode a marketId tuple of (-1,-1) to represent this.
Back to the report - the report needed to show every FAQ question/answer and the markets that displayed this FAQ in a 2D matrix (we used an Excel spreadsheet). I found that the easiest way to associate each FAQ to each market in the default market selection case was with this query, unioning the exploded result with all other direct FAQ-market associations.
The Faq2LevelDefault table holds all of the markets that are defined as being in the default selection (I believe it was just a list of marketIds).
SELECT FaqId, fld.LevelId, 1 [Exists]
FROM Faq2Levels fl
CROSS JOIN Faq2LevelDefault fld
WHERE fl.LevelId=-1 and fl.LevelNumber=-1 and fld.LevelNumber=4
UNION
SELECT Faqid, LevelId, 1 [Exists] from Faq2Levels WHERE LevelNumber=4
You might want to create a report using all of the possible combinations from two lookup tables, in order to create a report with a value for every possible result.
Consider bug tracking: you've got one table for severity and another for priority and you want to show the counts for each combination. You might end up with something like this:
select severity_name, priority_name, count(*)
from (select severity_id, severity_name,
priority_id, priority_name
from severity, priority) sp
left outer join
errors e
on e.severity_id = sp.severity_id
and e.priority_id = sp.priority_id
group by severity_name, priority_name
In this case, the cartesian join between severity and priority provides a master list that you can create the later outer join against.
When running a query for each date in a given range. For example, for a website, you might want to know for each day, how many users were active in the last N days. You could run a query for each day in a loop, but it's simplest to keep all the logic in the same query, and in some cases the DB can optimize the Cartesian join away.
To create a list of related words in text mining, using similarity functions, e.g. Edit Distance