Just to clarify i can't change the tables structure, so please leave out the "you should change your tables to this and that" answers, thank you.
So i have a table entities_attributes_values where an entity has a lot of attributes and the value of that attribute, basically imagine 3 fields:
entity_id
entity_attributes_id
value
Because every entities attribute and its value is on row getting more values is not so easy i was thinking of multiple self joins, and because this query will be very common i created a view, which is built with this query:
SELECT `L1`.`entity_id`,
`L1`.`value` as 'company_id',
`L2`.`value` as 'entity_name',
`P`.`value` as 'person_name',
`L4`.`value` as 'establishment_id',
`L5`.`value` as 'department_id'
FROM `entities_attributes_values` `L1`
LEFT JOIN `entities_attributes_values` `L2` ON `L1`.`entity_id` = `L2`.`entity_id` AND `L2`.`entity_attributes_id` = 1
LEFT JOIN `entities_attributes_values` `L3` ON `L1`.`entity_id` = `L3`.`entity_id` AND `L3`.`entity_attributes_id` = 3
LEFT JOIN `persons_attributes_values` `P` ON `L3`.`value` = `P`.`core_persons_id` AND `P`.`core_persons_attributes_id` = 4
LEFT JOIN `entities_attributes_values` `L4` ON `L1`.`entity_id` = `L4`.`entity_id` AND `L4`.`entity_attributes_id` = 12
LEFT JOIN `entities_attributes_values` `L5` ON `L1`.`entity_id` = `L5`.`entity_id` AND `L5`.`entity_attributes_id` = 13
WHERE `L1`.`entity_attributes_id` = 2
So this works but i have one problem i get "duplicate" values and its not really duplicate but the point is that in my view i want every entity to be only one row with all its attributes values but instead i get this:
So as you can see the first three result are not good for me, i only need the fourth one, where i have all my data about one entity.
Thank you in advance for any help!
Try using conditional aggregation instead:
select eav.entity_id,
max(case when entity_attributes_id = 2 then eav.value end) as company_id,
max(case when entity_attributes_id = 1 then eav.value end) as entity_name,
max(case when entity_attributes_id = 3 then eav.value end) as company_name,
. . .
from entities_attributes_values eav
group by eav.entity_id;
This will make it easy to add new attributes to the view. Also, don't use single quotes to delimit column names. Single quotes should only be used for date and time constants.
Related
Hopefully i can explain this well enough. I have a bit of a unique issue where the customer system we use can change a ID in the database in the background based on the products status.
What this means is when i want to report old products we don't use anymore along side active products there ID differs between the two key tables depending on there status. This means Active products in the product table match that of the stock item table with both showing as 647107376 but when the product is no long active the StockItem table will present as 647107376 but the table that holds the product information the id presents as -647107376
This is proving problematic for me when i comes to joining the tables together to get the information needed. Originally i had my query set up like this:
SELECT
Company_0.CoaCompanyName
,SopProduct_0.SopStiStockItemCode AS hbpref
,SopProduct_0.SopStiCustomerStockCode AS itemref
,SopProduct_0.SopDescription AS ldesc
,StockMovement_0.StmOriginatingEntityID AS Goodsin
FROM
SBS.PUB.StockItem StockItem_0
LEFT JOIN SBS.PUB.SopProduct SopProduct_0 ON StockItem_0.StockItemID = SopProduct_0.StockItemID
LEFT JOIN SBS.PUB.Company Company_0 ON SopProduct_0.CompanyID = Company_0.CompanyID
LEFT JOIN SBS.PUB.StockMovement StockMovement_0 ON StockItem_0.StockItemID = StockMovement_0.StockItemID
WHERE
Company_0.CoaCompanyName = ?
AND StockMovement_0.MovementTypeID = '173355'
AND StockMovement_0.StmMovementDate >= ? AND StockMovement_0.StmMovementDate <= ?
AND StockMovement_0.StmQty <> 0
AND StockMovement_0.StockTypeID ='12049886'
Unfortunately though what this means is any of the old product will not show because there is no matching id due to the SopProduct table presenting the StockItemID with a leading -
So from this i thought best to use a case when statement with a nested concat and left in it to bring through the results but this doesn't appear to work either sample of the join below:
LEFT JOIN SBS.PUB.SopProduct SopProduct_0 ON (CASE WHEN LEFT(SopProduct_0.StockItemID,1) = "-" THEN CONCAT("-",StockItem_0.StockItemID) ELSE StockItem_0.StockItemID END) = SopProduct_0.StockItemID
Can anyone else think of a way around this issue? I am working with a Progress OpenEdge ODBC.
Numbers look like numbers. If they are, you can use abs():
ON StockItem_0.StockItemID = ABS(SopProduct_0.StockItemID)
Otherwise a relatively simple method is:
ON StockItem_0.StockItemID IN (SopProduct_0.StockItemID, CONCAT('-', SopProduct_0.StockItemID))
Note that non-equality conditions often slow down JOIN operations.
Using an or in the join should work:
LEFT JOIN SBS.PUB.SopProduct SopProduct_0
ON SopProduct_0.StockItemID = StockItem_0.StockItemID
OR
SopProduct_0.StockItemID = CONCAT("-", StockItem_0.StockItemID)
You might need to cast the result of the concat to a number (if the ids are stored as numbers).
Or you could use the abs function too (assuming the ids are numbers):
LEFT JOIN SBS.PUB.SopProduct SopProduct_0
ON SopProduct_0.StockItemID = abs(StockItem_0.StockItemID)
Good day,
I have a small issue with MySQL Distinct.
Trying the following query in my system :
SELECT DISTINCT `booking_id`, `booking_ticket`, `booking_price`, `bookingcomment_id`, `bookingcomment_message` FROM `mysystem_booking`
LEFT JOIN `mysystem_bookingcomment` ON `mysystem_booking`.`booking_id` = `mysystem_bookingcomment`.`bookingcomment_link`
WHERE `booking_id` = 29791
The point is that there are bookings like 29791 that have many comments added.
Let's say 10. Then when running the above query I see 10 results instead of one.
And that's not the way DISTINCT supposes to work.
I simply want to know if there are any comments. If the comment ID is not 0 then there is a comment. Of course I can add COUNT(blabla) as comment_number but that's a whole different story. For me now I'd like just to have this syntax right.
You may try aggregating here, to find which bookings have at least a single comment associated with them:
SELECT
b.booking_id,
b.booking_ticket,
b.booking_price
FROM mysystem_booking b
LEFT JOIN mysystem_bookingcomment bc
ON b.booking_id = bc.bookingcomment_link
WHERE
b.booking_id = 29791
GROUP BY
b.booking_id
HAVING
COUNT(bc.bookingcomment_link) > 0;
Note that depending on your MySQL server mode, you might have to also add the booking_ticket and booking_price columns to the GROUP BY clause to get the above query to run.
You can try below - using a case when expression
SELECT DISTINCT `booking_id`, `booking_ticket`, `booking_price`, `bookingcomment_id`,
case when `bookingcomment_message`<>'0' then 'No' else 'Yes' end as comments
FROM `mysystem_booking`
LEFT JOIN `mysystem_bookingcomment` ON `mysystem_booking`.`booking_id` = `mysystem_bookingcomment`.`bookingcomment_link`
WHERE `booking_id` = 29791
I'm brand new to SQL and I know this should be easy, but I can't seem to find any reference on how to do specifically what I'm looking for. I've check the archives and I can't find a basic example.
Anyway, all I want is -
SELECT
(COUNT (i.productNumber WHERE i.type = 'type1') AS 'Type 1'),
(COUNT (i.productNumber WHERE i.type = 'type2') AS 'Type 2'),
FROM items AS i
WHERE i.dateadded BETWEEN '2015-03-02' and '2015-03-04'
The two count conditions are different, but both of those queries share that date condition. I've done two distinct select statements and put a UNION between them. That works. The only issue is all of the data appears in one column under the first alias in the statement. I would need each alias to be a new column. I also have to write the date condition in twice.
You could group them by type so you would get a different row for each of them :
SELECT i.type, COUNT(i.productNumber)
FROM items i
WHERE i.dateadded BETWEEN '2015-03-02' AND '2015-03-04'
GROUP BY i.type;
If you really want to have one row, then you could do
SELECT COUNT(b.productNumber) AS 'type1', COUNT(c.productNumber) AS 'type2'
FROM items i
LEFT JOIN items b on b.productNumber = i.productNumber
LEFT JOIN items c on c.productNumber = i.productNumber
WHERE i.dateadded BETWEEN '2015-03-02' AND '2015-03-04'
AND b.type = 'type1'
AND c.type = 'type2';
I am having some trouble with my sql statement.
Here is a picture of the relevant tables:
A product can be in multiple categories.
A single product can have multiple varietycategories (ie: size, color, etc)
a varietycategory can have multiple varietycategoryoptions (ie: small, medium, large)
the table searchcriteria.criterianame loosly relates to varietycategory.category
the table searchcriteriaoption.criteriaoption loosely relates to varietycategoryoption.descriptor.
I get the searchcriteria.criterianame and use that string as the value we want to match with varietycategory.category and we also have to get the various searchcriteriaoption.criteriaoption strings (for that searchcriteria.criterianame) and match that against varietycategoryoption.descriptor for that varietycategory.category.
Here is the sql:
SELECT DISTINCT categories.*, product.*
FROM (categories, product, product_category)
LEFT JOIN varietycategory ON varietycategory.productid = product.id
LEFT JOIN varietycategoryoption ON varietycategoryoption.varietycategoryid = varietycategory.id
WHERE product_category.categoryid=4
AND product.id=product_category.productid
AND categories.category_id=product_category.categoryid
AND (
(varietycategory.category = 'color' AND (varietycategoryoption.descriptor='red' OR varietycategoryoption.descriptor='blue'))
OR
(varietycategory.category = 'size' AND (varietycategoryoption.descriptor = 'small' OR varietycategoryoption.descriptor='medium'))
)
but I get an error:
Unknown column 'varietycategory.id' in 'on clause'
I have tried to figure out what I am doing wrong. I tried simplifying the query a bit (just to try and determine what part of the sql query was causing the problem) to only match the searchcriteria.category string with the varietycategory.category and the query returns the data set correctly.
Here is the working query (this query is simplified and insufficient):
SELECT DISTINCT categories.*, product.*
FROM (categories, product, product_category)
LEFT JOIN varietycategory ON varietycategory.productid = product.id
WHERE product_category.categoryid=4
AND product.id=product_category.productid
AND categories.category_id=product_category.categoryid
AND (varietycategory.category = 'color' OR varietycategory.category = 'size' OR varietycategory.category='shape');
But I also need to be able to match against the varietycategoryoptions as well.
Just to avoid confusion, I am only using searchcriteria to get the field category and use it as a string to match against the varietycategory.category
and I am only using searchcriteriaoption to get the field criteriaoption and use it as a string to match against varietycategoryoption.descriptor
Does anyone know what I am doing wrong with my 1st query?
Please do help as SQL is not expertise.
Thank you!
The error is at:
OR
(varietycategory.category = 'size' (varietycategoryoption.desciptor = 'small' OR varietycategoryoption.descriptor='medium'))
^
|
An operator (AND, OR) is missing here
This has nothing to do with the join syntax, by the way.
Do not mix implicit and explicit joins. Your query should look like:
SELECT DISTINCT c.*, p.*
FROM product_category pc join
categories c
on c.category_id = pc.categoryid join
product p
on p.id = pc.productid join
varietycategory vc
ON vc.productid = p.id
WHERE c.categoryid = 4 AND
vc.category in ('color', 'size', 'shape');
You probably don't need the distinct, but that depends on the data. The left join is unnecessary because you are filtering on the second table in the where.
A simple rule: Never use commas in the from clause. To help, MySQL has scoping rules that can cause queries to break when you mix implicit and explicit join syntax.
The problem was a misspelled field on the table varietycategory, which I named
vcid, when I almost always name my table primary key id's "id".
I have tow tables, the first is mda_alert_info and the second is key_contacts_info. For each alert set up there may be multiple corresponding contacts. Both tables are linked by 3 columns mda_id, stage_id and ref_number and during the query I will have to pass figures values for them
How do I get all what I want from both tables in one statement. Below are the individual SELECT statements.
$result = mysql_query("SELECT `mda_name`, `project_name`, `ipc_id` FROM `mda_alert_info` WHERE `stage_id`=1 AND `mda_id`=2 AND `ref_number`= '444'");
This will always return one record
$result = mysql_query("SELECT `contact_role`, `contact_email`, `contact_ph_number` FROM `key_contacts_info` WHERE `stage_id`=1 AND `mda_id`=2 AND `role`=0 AND `ref_number`='444'");
This may return multiple records
I tried for a while and couldn't get it to work so I tried adding another field called 'me' to both tables which is basically concatting mda_id and stage_id strings then I tried the query below.
$result = mysql_query("SELECT key_contacts_info.contact_role, key_contacts_info.contact_email, key_contacts_info.contact_ph_number, mda_alert_info.mda_name, mda_alert_info.project_name, mda_alert_info.ipc_id FROM key_contacts_info LEFT JOIN mda_alert_info ON key_contacts_info.me = mda_alert_info.me WHERE stage_id=1 AND mda_id=2 AND role=0 AND ref_number='444'");
But it's still not working. What am I doing wrong and how do I get it to work.
UPDATE:
Sorry but I should clarify something on the relationship between the tables the three columns exist on each table but are not primary keys on either of the tables
SELECT a.*, b.*
FROM mda_alert_info a
INNER JOIN key_contacts_info b
ON a.mda_id = b.mda_id AND
a.stage_id = b.stage_id AND
a.ref_number = b.ref_number
WHERE b.role = 0 AND
a.stage_id = 1 AND
a.mda_id = 2 AND
a.ref_number = '444'
To further gain more knowledge about joins, kindly visit the link below:
Visual Representation of SQL Joins
select
a.mda_name,
a.project_name,
a.lpc_id,
k.contact_role,
k.contact_email,
k.contact_ph_number
from mda_alert_info a
join key_contacts_info k
on a.state_id = k.state_id
and a.mda_id = k.mda_id
and a.ref_number = k.ref_number
where a.state_id = 1
and a.mda_id = 2
and a.ref_number = '444'
and k.role = 0
;