Get "non-existing" values from database - mysql

I am having trouble with my database. I have three corresponding tables, where I in the first is holding some pages and in the second one holding some fields.
The third one is a table holding content to all fields in the pages.
Tables:
pages(PageID, Name)
fields(FieldID, FieldName);
pagefields(PageFieldID, FieldID, PageID)
pagefieldcontents(PageFieldContentID, PageFieldID, FieldID, PageID, Content)
What I need is to make sure, that EVEN if there in the table "pagefields" is NO value to a field, but if the field is related to the page (in the pagefields table), it will get returned as a row with value as an empty string.
What I am doing now is the following:
SELECT
pfc.ContentID as PFC_ContentID,
pfc.Content as PFC_FieldContent,
pfc.FieldID as PFC_FieldID
FROM
pagesfieldcontents pfc
INNER JOIN
pagefields pf
ON pf.PageID = pfc.PageID
INNER JOIN
fields ptf
ON pf.FieldID = ptf.FieldID
INNER JOIN
pages p
ON p.PageID = pf.PageID
WHERE
(some where-statement)
ORDER BY
somefield desc
Hope you can understand my question - have a nice day.

INNER JOINs require there to be a row in the joined table for the first tabke's row to be returned. But you may have fields that font have content and you shill want those returned...
Change all your INNER joins to LEFT joins:
SELECT
pfc.ContentID as PFC_ContentID,
pfc.Content as PFC_FieldContent,
pfc.FieldID as PFC_FieldID
FROM pages p
LEFT JOIN pagefields pf
ON p.PageID = pf.PageID
LEFT JOIN fields ptf
ON pf.FieldID = ptf.FieldID
LEFT JOIN pagesfieldcontents pfc
ON p.PageID = pfc.PageID
AND pf.FieldID = pfc.FieldID
WHERE some where-statement
ORDER BY somefield desc
I've also rearranged the table order and join conditions to what I guess you need.

Related

How can I populate a table when inner join values might be null?

I'm populating a table which is fetching the ids from 2 other tables to display their information, for example, delivery has a Hamburguer and the box, but the user might register the delivery with out the box, only with the hamburguer.
When I make a INNER JOIN SELECT to get the data from the DB it will return 0 results since there is no box and I'm trying to compare the ids that don't exist. It doesn't populate the table then.
SELECT
entrega_telemovel.*,
telemovel.id_telemovel,
telemovel.nroserie,
nro_telemovel.numero_telemovel,
nro_telemovel.id_nrotelemovel,
funcionarios.id_funcionario,
funcionarios.nome
FROM entrega_telemovel
INNER JOIN telemovel
ON entrega_telemovel.telemovel = telemovel.id_telemovel
INNER JOIN nro_telemovel
ON nro_telemovel.id_nrotelemovel = entrega_telemovel.numero_telemovel
INNER JOIN funcionarios
ON funcionarios.id_funcionario = entrega_telemovel.funcionario_entrega
ORDER BY funcionarios.nome;
In this query above entrega_telemovel.telemovel=telemovel.id_telemovel the value in entrega_telemovel.telemovel is null like the example I gave above. So 0 results are returned from the query.
How can I solve this ?
You are looking for a LEFT JOIN.
INNER JOIN only combines rows, that exist in both tables. A LEFT JOIN on the other hand always produces at least one row. If on table does not have a match for it, all columns are set to NULL.
SELECT
entrega_telemovel.*,
telemovel.id_telemovel,
telemovel.nroserie,
nro_telemovel.numero_telemovel,
nro_telemovel.id_nrotelemovel,
funcionarios.id_funcionario,
funcionarios.nome
FROM entrega_telemovel
LEFT JOIN telemovel
ON entrega_telemovel.telemovel = telemovel.id_telemovel
LEFT JOIN nro_telemovel
ON nro_telemovel.id_nrotelemovel = entrega_telemovel.numero_telemovel
LEFT JOIN funcionarios
ON funcionarios.id_funcionario = entrega_telemovel.funcionario_entrega
ORDER BY funcionarios.nome;
You want to show all entrega_telemovel entries, no matter whether they have a match in entrega_telemovel or not. This is what an outer join does.
SELECT ...
FROM entrega_telemovel et
LEFT OUTER JOIN telemovel t ON et.telemovel = t.id_telemovel
...

MySQL - How to get one of the repeated records given a condition in SQL?

I have the next results from a query. I did this:
Where the user "Adriana Smith" with ID 6 is repeated because she has different contract dates, to do that I did a left join from table bo_users to bo_users_contracts (1:m One to Many Relation). The query is below:
SELECT bo_users.ID, bo_users.display_name, COALESCE (bo_users_contracts.contract_start_date,'-') AS contract_start_date, COALESCE (bo_users_contracts.contract_end_date, '-') AS contract_end_date, COALESCE (bo_users_contracts.current,'-') AS current
FROM bo_users
LEFT JOIN bo_users_contracts ON bo_users.ID = bo_users_contracts.bo_users_id
LEFT JOIN bo_usermeta ON bo_users.ID = bo_usermeta.user_id
WHERE (bo_usermeta.meta_key = 'role' AND bo_usermeta.meta_value = 'member')
But I want to get all users, but from user Adriana I just want to get the occurrence where "current" column = 1.
So the final result would be the 3 user's records:
Alejandro, Rhonda and Adriana (with "current" = 1)
Thank you!
Since you want to limit on a table being outer joined, the limit should be placed on the join itself so the all records from bo_users is retained. (as indicated desired by the outer join)
Essentially the limit is applied before the join so the unmatched records from BO_users to bo_users_contracts are kept. If applied after the join in a where clause the records from BO_user without a matching record would have a null value for current and thus be excluded when the current=1 filter is applied.
In this example the only values which should be in the where would be from table BO_USERS.
I'd even move the bo_usermeta filters to the join or you may lose bo_users; or the left join on the 3rd table should be an inner join.
SELECT bo_users.ID
, bo_users.display_name
, COALESCE (bo_users_contracts.contract_start_date,'-') AS contract_start_date
, COALESCE (bo_users_contracts.contract_end_date, '-') AS contract_end_date
, COALESCE (bo_users_contracts.current,'-') AS current
FROM bo_users
LEFT JOIN bo_users_contracts
ON bo_users.ID = bo_users_contracts.bo_users_id
and bo_users_contracts.current = 1
LEFT JOIN bo_usermeta --This is suspect
ON bo_users.ID = bo_usermeta.user_id
WHERE (bo_usermeta.meta_key = 'role' --this is suspect
AND bo_usermeta.meta_value = 'member') --this is suspect
The lines reading this is suspect are that way because you have a left join which means you want all users from bo_users.. However if a user doesn't have a meta_key or meta_value defined, they would be eliminated. Either change the join to an inner join or move the where clause limits to the join. I indicate this as you're query is "inconsistent" in it's definition leading to ambiguity when later maintained.

Avoid Duplicate in Mysql Left Join Query

i have to take data from three tables like Userdetails,tasks,timedetails so i am getting data but it is duplicating based on the timedetails table. for example person id is - 1. it is presented two times in timedetails table then i'm getting duplicate rows.
my query is
SELECT GROUP_CONCAT(B.task_status) as task_status,
GROUP_CONCAT(B.task_type) as task_type,
GROUP_CONCAT(B.task_id) as task_id,
GROUP_CONCAT(B.task_name) as task_name,
A.us_id,
A.us_name,
C.out_time
FROM ts_userdetails A
LEFT JOIN
cms_task B
ON B.emp_id = A.us_id
LEFT JOIN
ts_timedetails C
ON C.user_id=A.us_id
WHERE C.entry_date='2017-05-09' AND
A.us_id!='1'
GROUP BY C.user_id
I am getting results like
I don't want duplicated things in displayed fields.
If I have 2 timedetails for one particular person id means 2 times duplication occurs. I just want one time.
use distinct keyword
SELECT GROUP_CONCAT(distinct B.task_status) as task_status,GROUP_CONCAT(distinct B.task_type) as task_type,GROUP_CONCAT(distinct B.task_id) as task_id,GROUP_CONCAT(distinct B.task_name) as task_name,A.us_id,A.us_name,C.out_time FROM ts_userdetails A LEFT JOIN cms_task B ON B.emp_id = A.us_id LEFT JOIN ts_timedetails C ON C.user_id=A.us_id WHERE C.entry_date='2017-05-09' AND A.us_id!='1' GROUP BY C.user_id

Need mysql query to pull data from two tables

So after helpful feedback from my original question, I now have this query:
SELECT sessions.id, sessions.title, sessions.abstract, sessions.presenters, sessions.proposal_id, proposals.outcomes, proposals.CategorySelection, proposals.research3, proposals.research4, proposals.research5, proposals.research6, proposals.innovation3, proposals.innovation4, proposals.innovation5,proposals.innovation6, proposals.application3, proposals.application4, proposals.application5, proposals.application6, proposals.integration3, proposals.integration4, proposals.integration5, proposals.integration6, proposals.references, proposals.organization
FROM sessions, proposals
INNER JOIN proposals ON proposals.id = sessions.proposal_id
WHERE sessions.id = '$id
LIMIT 1;)
that is getting me nowhere fast. What am I doing wrong?
Original question:
I need to pull several fields from one table and several more from a second table. The criteria is that a field called proposal_id match the id field of the second table. I am fairly new so this is what I have so far. It is not working, but not sure how to make it work.
(SELECT `title`,`abstract`,`presenters`,`proposal_id` FROM `sessions` WHERE `id`='$id')
UNION
(SELECT `outcomes`,`CategorySelection`,`research3`,`research4`,`research5`,`research6`,`innovation3`,`innovation4`,`innovation5`,
`innovation6`,`application3`,`application4`,`application5`,`application6`,`integration3`,`integration4`,`integration5`,`integration6`,`references`,`organization` FROM `proposals` WHERE `id`= `sessions`.`proposal_id`)
LIMIT 1;
You need to use JOIN not UNION
select
s.*,p.*
from `sessions` s
inner join `proposals` p on p.id = s.proposal_id
where s.id = '$id'
This is how you can join both the tables using the common key between.
You can select the specific fields instead of .* by specifying the column names as
s.col1,s.col2,p.col1,p.col2
etc
Try to use JOINS, where you can match the related fields from both the tables , this is the most convenient way to fetch records from multiple tables
UNION is used when you want to combine two queries
select a.id,b.some_field from table1 as a
INNER JOIN table2 as b ON b.prospal_id = a.id

Getting Repeated values in SQL

I was desperately trying harder and harder to get this thing done but didn`t yet succeed. I am getting repeated values when i run this query.
select
tbl_ShipmentStatus.ShipmentID
,Tbl_Contract.ContractID,
Tbl_Contract.KeyWinCountNumber,
Tbl_Item.ItemName,
Tbl_CountryFrom.CountryFromName,
Tbl_CountryTo.CountryToName,
Tbl_Brand.BrandName,
Tbl_Count.CountName,
Tbl_Seller.SellerName,
Tbl_Buyer.BuyerName,
Tbl_Contract.ContractNumber,
Tbl_Contract.ContractDate,
tbl_CountDetail.TotalQty,
tbl_CostUnit.CostUnitName,
tbl_Comission.Payment,
tbl_Port.PortName,
Tbl_Contract.Vans,
tbl_Comission.ComissionPay,
tbl_Comission.ComissionRcv,
tbl_CountDetail.UnitPrice,
tbl_Comission.ComissionRemarks,
tbl_CountDetail.Amount,
tbl_LCStatus.LCNumber,
tbl_ShipmentStatus.InvoiceNumber,
tbl_ShipmentStatus.InvoiceDate,
tbl_ShipmentStatus.BLNumber,
tbl_ShipmentStatus.BLDate,
tbl_ShipmentStatus.VesselName,
tbl_ShipmentStatus.DueDate
from tbl_ShipmentStatus
inner join tbl_LCStatus
on
tbl_LCStatus.LCID = tbl_ShipmentStatus.LCStatusID
inner join Tbl_Contract
on
tbl_LCStatus.ContractID = Tbl_Contract.ContractID
inner join Tbl_CountDetail
on Tbl_Contract.ContractID = Tbl_CountDetail.ContractId
inner join tbl_Comission
on
tbl_Comission.ContractID = Tbl_Contract.ContractID
inner join Tbl_Item
on
Tbl_Item.ItemID = Tbl_Contract.ItemID
inner join Tbl_Brand
on Tbl_Brand.BrandID = Tbl_Contract.BrandID
inner join Tbl_Buyer
on Tbl_Buyer.BuyerID = Tbl_Contract.BuyerID
inner join Tbl_Seller
on Tbl_Seller.SellerID = Tbl_Contract.SellerID
inner join Tbl_CountryFrom
on Tbl_CountryFrom.CountryFromID = Tbl_Contract.CountryFromID
inner join Tbl_CountryTo
on
Tbl_CountryTo.CountryToID = Tbl_Contract.CountryToID
inner join Tbl_Count
on
Tbl_Count.CountID = Tbl_CountDetail.CountId
inner join tbl_CostUnit
on tbl_Comission.CostUnitID = tbl_CostUnit.CostUnitID
inner join tbl_Port
on tbl_Port.PortID = tbl_Comission.PortID
where tbl_LCStatus.isDeleted = 0
and tbl_ShipmentStatus.isDeleted =0
and tbl_LCStatus.isDeleted = 0
and Tbl_CountDetail.isDeleted = 0
and Tbl_Contract.isDeleted = 0
and tbl_ShipmentStatus.LCStatusID = 5
I have also attached a picture of my result set of rows.
Any suggestions why this is happening would really be appreciable.
Result Set
Typically this happens when you have an implicit partial cross join (Cartesian product) between two of your tables. That's what it looks like to me here.
This happens most often when you have a many-to-many relationship. For example, if a single Album allows both multiple Artists and multiple Songs and the only relationship between Artists and Songs is Album, then there's essentially a many-to-many relationship between Artists and Songs. If you select from all three tables at once you're going to implicitly cross join Artists and Songs, and this may not be what you want.
Looking at your query, I see many-to-many between Tbl_CountDetail and tbl_Comission through Tbl_Contract. Try eliminating one of those joins to test to see if the behavior disappears.
Try using the DISTINCT keyword. It should solve your issue
Select DISTINCT ....
Wait as far as I can see your records are not duplicates.
HOWEVER
Notice the CountName column and Shipment ID column
The combination is unique for every row. Hence the values are unique as far as I can see. Try not selecting CountName.
Well if you have distinct rows its not a duplication problem. The issue is during the join a combination is occurring you don't want it to duplicating the results.
Either don't select CountName or you have a mistake in your data.
Only one of those rows should be true either 6 with Count2 or 6 with Count1. Likewise for 7. The fact that your getting both when your not supposed to indicates a logic mistake