Join two SQL Queries based on first query answer - mysql

I have been looking everywhere and this would be the best website to ask someone for the help. I have to make SQL query that checks the total amount of bookings for the specific flight and then based on the number of bookings the system should provide the choice of an aircraft. First query works and it finds total number of bookings and i think i have the case statement right to choose an aircraft but i cant find the way of physically joining both queries , i tried to use unison , inner join and nested queries but it appears that Total number of seats booked (the answer from first query ) cannot be found please help me guys.
First SQL Query(find total number of bookings )
SELECT count(bookingdetails.FlightID)AS TotalNumberOfSeatsBooked,flightdetails.FlightID
FROM bookingdetails, bookingdetails AS TEMP,flightdetails
WHERE bookingdetails.BookingID = TEMP.BookingID
AND bookingdetails.FlightID= flightdetails.FlightID
Group BY FlightID;
SECOND SQL Query(Choose an aircraft type depending on how many bookings are made)
SELECT CASE chooseaircraft
WHEN TotalNumberOfSeatsBooked <= 110 THEN 'BA 146-200'
ELSE'Embraer 170'
END AS ChoiceOfAircraft
FROM aircrafttype;
Big Thanks to everyone
After one answer i think im heading in the right direction with merging the both queries together , the code now displays the total number of seats and flight number in the sub query but the choice of aircraft column still doesnt show but it does if you run the query by it self i know i am close to getting this and i would appreciate any help to become better in SQL the code i have now is :
SELECT count(bookingdetails.FlightID)AS TotalNumberOfSeatsBooked,flightdetails.FlightID
FROM bookingdetails, bookingdetails AS TEMP,flightdetails
WHERE bookingdetails.BookingID = TEMP.BookingID
AND bookingdetails.FlightID= flightdetails.FlightID
AND bookingdetails.FlightID= flightdetails.FlightID IN(
SELECT CASE WHEN count(bookingdetails.FlightID) <= 110 THEN 'BA 146-200'
ELSE'Embraer 170'
END AS ChoiceOfAircraft
FROM bookingdetails,flightdetails)
Group BY FlightID;

You can use the same expression count(bookingdetails.FlightID) in your CASE statement (or) wrap your first query in a subquery and access the column in your outer query. That is
CASE WHEN count(bookingdetails.FlightID) <= 110 THEN 'BA 146-200'
ELSE'Embraer 170'
END AS ChoiceOfAircraft

Related

MySQL INNER JOIN with GROUP BY and COUNT(*)

I've never been able to get my head around INNER JOINs (or any other JOIN types for that matter) so I'm struggling to work out how to use it in my specific situation. In fact, I'm not even sure if it's what I need. I've looked at other examples and read tutorials but my brain just doesn't seem to work the way needed to truly get it (or it doesn't function at all).
Here's the scenario:
I have two tables -
phone_numbers - this table has a list of phone numbers that
belong to lots of different customers. A single customer can have
multiple numbers. For simplicity's sake, we'll say the fields are
'number_id', 'customer_id', 'phone_number'.
call_history - this table has a record of every single call that one of these
numbers in the first table could have had. There's a record for
every individual call going back years. Again, for simplicity,
we'll say the relevant fields are customer_id, phone_number,
call_start_time.
What I'm trying to accomplish is to find all of the numbers that belong to a particular customer_id in the phone numbers table and use that information to search through the call_history table and find the number of calls each phone number has received, and group that by the number of calls for each number, preferably also showing zeros where a number hasn't received any calls at all.
The reason the zero calls is important is because that's the data I'm interested in. Otherwise, I could just get all the information out of the call_history table. But what I'm trying to achieve is find the numbers with no activity.
All I've been able to accomplish is run one query to get all of the numbers belonging to one customer:
SELECT customer_id, phone_number FROM phone_numbers WHERE customer_id = Y;
Then run a second query to get all phone calls for that customer_id for a set duration:
SELECT customer_id, phone_number, COUNT(*) FROM call_history WHERE customer_id = Y and call_start_time >= DATE_SUB(SYSDATE(), INTERVAL 30 DAY) GROUP BY phone_number;
I've then had to use the data returned from both queries and use a VLOOKUP function in Excel to match number of calls for each individual number from the second query to the list of all numbers from the first query, thus leaving blanks in my "all numbers" table and identifying those numbers that had no calls for that time period.
I'm hoping there's some way to do all of this with a single query and return a table of results, listing the zero number of calls with it and eliminate the whole manual Excel bit as it's not overly efficient and prone to human error.
Without at least a workable example from you, it's not easy to re-create your situation. Anyway, INNER JOIN might not return the result as how you expected. In my short time with MySQL, I mainly use 2 types of JOIN; one is already mentioned and the other is LEFT JOIN. From what I can understand in your question, what you want to achieve can be done by using LEFT JOIN instead of INNER JOIN. I may not be the best person to explain this to you but this is how I understand it:
INNER JOIN - only return anything that match in ON clause between two (or more) tables.
LEFT JOIN - will return everything from the table on the left side of the join and return NULL if ON get no match in the table on the right side of the join .. unless you specify some WHERE condition from something on the right table.
Now, here is my query suggestion and hopefully it'll be useful for you:
SELECT A.customer_id, A.phone_number,
SUM(CASE WHEN call_start_time >= DATE_SUB(SYSDATE(), INTERVAL 30 DAY)
THEN 1 ELSE 0 END) AS Total
FROM phone_numbers A
LEFT JOIN call_history B
ON A.customer_id=B.customer_id
GROUP BY A.customer_id,A.phone_number;
What I did here is I LEFT JOIN phone_numbers table with call_history on customer_id and I re-position the WHERE call_start_time >= .. condition into a CASE expression in the SELECT since putting it at WHERE will turn this into a normal join or inner join instead.
Here is an example fiddle : https://www.db-fiddle.com/f/hriFWqVy5RGbnsdj8i3aVG/1
For Inner join You should have to do like this way..
SELECT customer_id,phone_number FROM phone_numbers as pn,call_history as ch where pn.customer_id = ch.customer_id and call_start_time >= DATE_SUB(SYSDATE(), INTERVAL 30 DAY) GROUP BY phone_number;
Just add table name whatever you want to join and add condition

MYSQL - Syntax for Joining My 3 Tables Correctly

Edit2: Chose to separate the queries and collate/handle the information as a whole outside of the database's output. Taking these out in a .CSV format, and adding them into Excel where I'm going to be running the actual numbers.
Query 1 to pull out orders and desired info:
SELECT
shipstation_orders_v2.id AS SSO_id,
shipstation_orders_v2.order_number AS SSO_orderNumber,
shipstation_orders_v2.order_id AS SSO_orderID,
shipstation_orders_v2.storename AS SSO_storeName,
shipstation_orders_v2.order_date AS SSO_orderDate,
shipstation_orders_v2.order_total AS SSO_orderTotal,
shipstation_orders_v2.name AS SSO_name,
shipstation_orders_v2.company AS SSO_company
FROM shipstation_orders_v2
GROUP BY shipstation_orders_v2.id,
shipstation_orders_v2.order_number,
shipstation_orders_v2.order_id,
shipstation_orders_v2.storename,
shipstation_orders_v2.order_date,
shipstation_orders_v2.order_total,
shipstation_orders_v2.name,
shipstation_orders_v2.company
ORDER BY SSO_orderDate
Query 2 to pull out fulfillments and equivalent info:
SELECT DISTINCT
shipstation_orders_v2.id AS SSO_id,
shipstation_fulfillments.id AS SSF_id,
shipstation_fulfillments.order_number AS SSF_orderNumber,
shipstation_orders_v2.order_number AS SSO_orderNumber,
shipstation_orders_v2.order_id AS SSO_orderID,
shipstation_orders_v2.storename AS SSO_storeName,
shipstation_orders_v2.order_date AS SSO_orderDate,
shipstation_fulfillments.order_date AS SSF_orderDate,
shipstation_orders_v2.order_total AS SSO_orderTotal,
shipstation_fulfillments.amount_paid AS SSF_amountPaid,
shipstation_orders_v2.name AS SSO_name,
shipstation_orders_v2.company AS SSO_company,
shipstation_fulfillments.name AS SSF_name,
shipstation_fulfillments.company AS SSF_company
FROM shipstation_fulfillments
INNER JOIN shipstation_orders_v2
ON shipstation_fulfillments.order_number =
shipstation_orders_v2.order_number
WHERE shipstation_fulfillments.order_number =
shipstation_orders_v2.order_number
GROUP BY shipstation_orders_v2.id,
shipstation_fulfillments.id,
shipstation_fulfillments.order_number,
shipstation_orders_v2.order_number,
shipstation_orders_v2.order_id,
shipstation_orders_v2.storename,
shipstation_orders_v2.order_date,
shipstation_fulfillments.order_date,
shipstation_orders_v2.order_total,
shipstation_fulfillments.amount_paid,
shipstation_orders_v2.name,
shipstation_orders_v2.company,
shipstation_fulfillments.name,
shipstation_fulfillments.company
Edit: Question marked as answered. I figured out another way to do it that wasn't quite as harebrained. Props to DRapp for getting my brain moving.
Original Code is below Wall of Text
I'm a self-taught MySQL database user. I won't say administrator, since it's just me. I've put together a small database for work - about 60,000 rows and a maximum of 51 columns spread over three tables. I use this at work as a way to organize a fairly disparate sales data setup and make sense of it to identify trends, seasonality, all that good stuff. I work primarily with Shipstation data.
My problem is when I needed to introduce this third table. With two tables, obviously, it's just a simple JOIN. I got that working just fine. I'm having quite a bit of trouble setting up the JOINs correctly for this third table.
I'm attempting to JOIN the data from the two innermost queries to shipstation_orders_v2 and order_keys to the shipstation_fulfillments results I have in the third table.
For those of you who don't use Shipstation or aren't familiar with this element of it, fulfillments are in a different category than orders and don't use quite the same data. This is my dirty way of gluing them together so we have some decent, manipulable information on sales and shipping trends, etc.
I am making an internal query from shipstation_orders_v2 to order_keys as a way to SELECT DISTINCT the sum totals of split orders. I had problems with data duplication before I built up that subquery. With the (now) subquery and sub-subquery, the duping problem has been eliminated and with just those two tables it worked fine.
The issue is, when I'm making the SELECT from shipstation_fulfillments with a JOIN to the subquery and sub-subquery, I'm hitting a roadblock.
I've gotten several errors while working on this query. In order of occurrence and resolution:
Error 2013, lost connection to server during query (which told me I'm doing a full table read on three joined tables, since it isn't erroring out beforehand, but my rinkadink setup can't handle it). I got rid of that one.
Then, Error 1051 for an unidentified table name shipstation_fulfillments. To me I think it might be an issue for the query aliases. I am not sure.
Finally, good ole Error 1064, incorrect syntax on the first subquery after the
SELECT shipstation_fulfillments arguments.
Being self-taught, I'd virtually guarantee I'm merely missing an element of syntax somewhere that would appear fairly obvious to a well-practiced user of MySQL. Below is my current query setup.
If there needs to be any clarification, let me know.
SELECT
`shipstation_fulfillments`.`order_date` AS `orderDate`,
`shipstation_fulfillments`.`order_number` AS `orderNumber`,
(`shipstation_fulfillments`.`amount_paid` + `shipstation_fulfillments`.`tax_paid`) AS "Total Paid",
`shipstation_fulfillments`.`name` AS `name`,
`shipstation_fulfillments`.`company` AS `company`,
FROM
(
(SELECT
COUNT(`shipstation_orders_v2`.`order_key`) AS `orderCount`,
`shipstation_orders_v2`.`key_id` AS `key_id`,
`shipstation_orders_v2`.`order_number` AS `order_number`,
MAX(`shipstation_orders_v2`.`order_date`) AS `order_date`,
`shipstation_orders_v2`.`storename` AS `store`,
(`shipstation_orders_v2`.`order_total` - `shipstation_orders_v2`.`shippingPaid`) AS `orderPrice`,
`shipstation_orders_v2`.`shippingpaid` AS `shippingPaid`,
SUM(`shipstation_orders_v2`.`shippingpaid`) AS `SUM shippingPaid`,
`shipstation_orders_v2`.`order_total` AS `orderTotal`,
SUM(`shipstation_orders_v2`.`order_total`) AS `SUM Total Amount Paid`,
`shipstation_orders_v2`.`qtyshipped` AS `qtyShipped`,
SUM(`shipstation_orders_v2`.`qtyshipped`) AS `SUM qtyShipped`,
`shipstation_orders_v2`.`name` AS `name`,
`shipstation_orders_v2`.`company` AS `company`
FROM
(SELECT DISTINCT
`order_keys`.`key_id` AS `key_id`,
`order_keys`.`order_key` AS `order_key`,
`shipstation_orders_v2`.`order_number` AS `order_number`,
`shipstation_orders_v2`.`order_id` AS `order_id`,
`shipstation_orders_v2`.`order_date` AS `order_date`,
`shipstation_orders_v2`.`storename` AS `storename`,
`shipstation_orders_v2`.`order_total` AS `order_total`,
`shipstation_orders_v2`.`qtyshipped` AS `qtyshipped`,
`shipstation_orders_v2`.`shippingpaid` AS `shippingpaid`,
`shipstation_orders_v2`.`name` AS `name`,
`shipstation_orders_v2`.`company` AS `company`
FROM
(`shipstation_orders_v2`
JOIN `order_keys` ON ((`order_keys`.`order_key` = `shipstation_orders_v2`.`order_id`)))) `t`)
JOIN `shipstation_fulfillments`
ON (`shipstation_orders_v2`.`order_number` = `shipstation_fulfillments`.`order_number`)) `w`
As a couple notes... As for long table names, no problem, but you can use alias references to them such as I have done via example ...ShipStation_Fulfillments SSF... the "SSF" is now an alias for shorter typing yet still makes sense of origin.
When changing column names in query via "AS", you only need the as if your column name result will change from its original as you had in the beginning such as SSF.order_date AS orderDate where you remove the "_" from the final column name, but also in "Total Paid" (yet I HATE column names with embedded spaces, let the user interface handle labeling things, but thats just me).
When typing table.column (or alias.column), doing via CamelCasing helps readability vs camelcasing slightly harder to read where the brain naturally breaks into readable words for us.
Other issue based on query. Outer query portions can't recognize aliases from inner closed queryies, only the alias of the subselect as you had with the "t" and "w" aliases.
Next, when doing JOINs, my preference is to read them in the way the tables are within the query listing the first one on the left, and whatever is joined TO on the right.
If went from Table A Join to Table B, the ON clause would be ON A.KeyID = B.KeyID vs B.KeyID = A.KeyID especially if you are going several tables... A->B, B->C, C->D
Any query with aggregates (sum, avg, count, min, max, etc) must have a "GROUP BY" clause to identify when each record should break. In your example, I would assume break on the original sales order.
Although this query IS NOT WORKING, here is a cleaned-up version of your query showing implementations from above.
SELECT
SSF.order_date AS OrderDate,
SSF.order_number AS OrderNumber,
(SSF.amount_paid + SSF.tax_paid) AS `Total Paid`,
SSF.name,
SSF.company
FROM
( SELECT
SSOv2.key_id,
SSOv2.order_number,
SSOv2.storename AS store,
SSOv2.order_total - SSOv2.shippingPaid AS OrderPrice,
SSOv2.ShippingPaid,
SSOv2.order_total AS OrderTotal,
SSOv2.QtyShipped,
SSOv2.name,
SSOv2.company,
COUNT(SSOv2.order_key) AS orderCount,
MAX(SSOv2.order_date) AS order_date,
SUM(SSOv2.shippingpaid) AS `SUM shippingPaid`,
SUM(SSOv2.order_total) AS `SUM Total Amount Paid`,
SUM(SSOv2.qtyshipped) AS `SUM qtyShipped`
FROM
( SELECT DISTINCT
OK.key_id AS key_id,
OK.order_key AS order_key,
SSOv2.order_number AS order_number,
SSOv2.order_id AS order_id,
SSOv2.order_date AS order_date,
SSOv2.storename AS storename,
SSOv2.order_total AS order_total,
SSOv2.qtyshipped AS qtyshipped,
SSOv2.shippingpaid AS shippingpaid,
SSOv2.name AS name,
SSOv2.company AS company
FROM
shipstation_orders_v2 SSOv2
JOIN order_keys
ON SSOv2.order_id = OK.order_key
JOIN shipstation_fulfillments SSF
ON SSOv2.order_number = SSF.order_number ) t
) w
Next, without seeing actual data or listed structures critical to solve the query, I will ask you edit your existing post. Create a sample table listing table, columns and sample data so we can see the basis of what you are aggregating and trying to get out of the query. Especially show where there could be multiple rows per order and fulfillment respectively and a sample answer of what you EXPECT the results to show.

Get average number from SQL statement

I've got a SQL statement:
SELECT AVG(`totalhours`)/5 AS `average`,* FROM `report_signout` JOIN `employee` ON `employee`.`username`=`report_signout`.`username`
However it's not working. Basically I need to calculate the average total hours an employee has been on the premises in any one week, the assumption is accepted that the office is only open 5 days a week. The total hours are coming from the table report_signout which I need to join on the username of the employee table so I can produce an outcome where I can then list the Firstname and Lastname of the employee along with the average hours on a web page. That last part is done in PHP which I already know how to do. I just need to see where I'm going wrong with the SQL statement.
If someone could point out to me please or give me a bit of help it would be much appreciated, thanks!
MySQL does not really know what totalhours is. As you are referencing more than one table, a table is not assumed, so you need to declare what to average by defining the reference as:
`table name`.`column name`
This is true for most if not all MySQL built in functions. Use absolute declarations (ie those with table and column names both defined, as above) as much as possible.
SELECT AVG(`report_signout`.`totalhours`)/5 AS `average`,
`report_signout`.*, `employee`.*
FROM `report_signout`
INNER JOIN `employee` ON `employee`.`username` = `report_signout`.`username`
As a small aside, try and avoid vague JOIN referencing instead using a complete JOIN reference, which states the type of JOIN rather than an assumption.
Also try to avoiding using * selection instead stating each column you wish to call.

something wrong with the result of mysql query with joins and select

Good day,
I am trying to join 3 tables for my inventory report but I am getting weird results out of it.
my query
SELECT i_inventory.xid,
count(x_transaction_details.xitem) AS occurrence,
i_inventory.xitem AS itemName,
SUM(i_items_group.or_qty) AS `openingQty`,
avg(x_transaction_details.cost) AS avg_cost,
SUM(x_transaction_details.qty) AS totalNumberSold,
SUM(i_items_group.or_qty) - SUM(x_transaction_details.qty) AS totalRemQty
FROM x_transaction_details
LEFT JOIN i_inventory ON x_transaction_details.xitem = i_inventory.xid
LEFT JOIN i_items_group ON i_inventory.xid = i_items_group.xitem
WHERE (x_transaction_details.date_at BETWEEN '2015-01-18 03:14:54' AND '2015-10-18 03:14:54')
AND i_inventory.xid = 3840
GROUP BY x_transaction_details.xitem
ORDER BY occurrence DESC
This query gives me this result:
See the openingQty column, I then tried to do a simple query to verify the result,
here's my query for checking the openingQty with joining only 2 tables i_items_group table (batches are stored) and i_inventory table (item Information are stored).
SELECT i_inventory.xid,
i_inventory.xitem,
SUM(i_items_group.or_qty) AS openingQty,
i_items_group.cost
FROM i_inventory
INNER JOIN i_items_group ON i_inventory.xid = i_items_group.xitem
WHERE i_inventory.xid = 3840
AND (i_items_group.date_at BETWEEN '2015-01-18 03:14:54' AND '2015-10-18 03:14:54')
my result was:
which is the correct data.
I also made a query on my x_transaction_details table also to verify if its correct or not.
heres my query:
select xitem, qty as qtySold from x_transaction_details where xitem = 3840
AND (date_at BETWEEN '2015-01-18 03:14:54' AND '2015-10-18 03:14:54')
result:
Which would total to: 15-quatitySold.
I'm just confused on how did I get 3269 as a result of my query where as the true openingQty should be only 467.
I guess the problem was in my query with joins, its messing up with number of transactions then it sums it up (I really dont know though).
Can you please help me identify it, and help me come up with the correct query.
This is a common problem with multiple SUM statements in a single query. Keep in mind how SQL does aggregation: first it generates a set of data that is not aggregated, then it aggregates it. Try your query without the GROUP BY or aggregate functions, and you'll be surprised what you turn up. There aren't enough of the right details in your post for me to determine where the breakdown is, but I can guess.
It looks like you have an xitem corresponding to some kind of product, then you have joined that to both transactions and items groups. Suppose a particular xitem matches with 3 transactions and 5 item groups. You'll get 15 records from that join. And when you sum it, any SUM calculations based on fields from the transaction table will be 5x higher than you expect, and any SUM calculations from the item groups table will be 3x higher than you expect. The key symptom here is the aggregate result being a multiple of the correct value, but seemingly different multiples for different rows.
There are multiple ways to address this kind of error. Some developers like to calculate one of hte aggregates in a subquery, then do the other aggregate in the main query and group by the already correct result from the subquery. Others like to write in-line queries to do the aggregate right in the expression:
SELECT xitem, (SELECT SUM(i_items_group.or_qty) FROM i_items_group WHERE i_inventory.xid = i_items_group.xitem) AS `openingQty`
, -- select more fields
Find what approach works best for you. But if you want to see the evidence for yourself, run this query with the aggregates gone and you'll see why those SUMs are doing what they are doing:
SELECT i_inventory.xid,
x_transaction_details.xitem AS occurrence,
i_inventory.xitem AS itemName,
i_items_group.or_qty,
x_transaction_details.cost,
x_transaction_details.qty,
i_items_group.or_qty - x_transaction_details.qty AS RemainingQty
FROM x_transaction_details
LEFT JOIN i_inventory ON x_transaction_details.xitem = i_inventory.xid
LEFT JOIN i_items_group ON i_inventory.xid = i_items_group.xitem
WHERE (x_transaction_details.date_at BETWEEN '2015-01-18 03:14:54' AND '2015-10-18 03:14:54')
AND i_inventory.xid = 3840
ORDER BY occurrence DESC

MySQL advanced sub query repetition

I'm writing some reasonably complex queries for reporting for an app I am developing. I could probably achieve all of the following through using higher level PHP, but obviously I would like to get it all done with MySQL which will obviously simplify things greatly.
The report I need is a typical sales report type query, which will list a list of people, and some relevant totals relating to them. The only minor difference is that this system relates to freight/haulage, so the "sales people" are actually lorry drivers, and the "sales" are individual consignments. Also, consignments are only linked/tied to their respective driver through the creation of "routes", which record who delivers/collects what on a specific day.
Naturally, I could use an INNER JOIN to get a list of each driver, with all of the consignments they have delivered/collected, and SUM the revenue made off these. The problem comes however, when I need to show both a column for total delivery revenue and collection revenue. These figures can come from a consignments table, which lists every consignment. Each consignment can have a flag (ENUM "D","C") which donates whether it is a delivery or collection. This can almost be ascertained easily through using sub queries but still, there will be a lot of repetition.
What I have so far:
SELECT pr.driver_callsign, d.first_name, d.last_name, sum(pc.revenue) AS total_revenue
FROM pallet_routes AS pr
INNER JOIN drivers AS d ON d.driver_callsign = pr.driver_callsign
INNER JOIN pallet_consignments AS pc ON pc.route_id = pr.route_id
GROUP BY pr.driver_callsign
ORDER BY d.driver_callsign ASC
This obviously returns a list of each driver, with the total amount of revenue made from all consignments they have tied to them.
What would be the most efficient way to further split this revenue SUM field up to show a SUM(revenue) WHERE type = "C" and SUM(revenue) WHERE type="D"? Subqueries? UNION?
It may also be worth mentioning that the end query will be narrowed down to a date range. So for example there will be a WHERE date BETWEEN x AND y put against the pallet_routes table.
Any advice would be greatfully received. Please do ask if you want me to elaborate more.
I don't know where your column type is, but if it's on pallet_consignments, you can try the following:
SELECT pr.driver_callsign, d.first_name, d.last_name,
SUM(IF(pc.`type` = 'C', pc.revenue, 0)) collection_revenue,
SUM(IF(pc.`type` = 'D', pc.revenue, 0)) delivery_revenue
FROM pallet_routes AS pr
INNER JOIN drivers AS d ON d.driver_callsign = pr.driver_callsign
INNER JOIN pallet_consignments AS pc ON pc.route_id = pr.route_id
GROUP BY pr.driver_callsign
ORDER BY d.driver_callsign ASC
Otherwise, please mention where the column type is.