I have a MySQL JOIN query where 2 tables are joined to get the output
select distinct (a.error_type),a.links_id, a.crawl_cycle , b.* from $table a inner join crawler_error_type b on a.error_type = b.error_type where a.projects_id = '$pid' and b.error_priority_page_level='High'
Now I want to check if the value of the field error_type is present in the third table. If it is present then it shouldn't give me the resulted row.
Add the below:
LEFT OUTER JOIN third_table c ON c.error_type = a.error_type
and
WHERE c.error_type is null
LEFT OUTER JOIN will display all the records from a table joining on third_table. Since you do not want the record with matching error type from third_table, use WHERE c.error_type is null
You need to add one more INNER JOIN on third_table as:
SELECT DISTINCT a.error_type, a.links_id, a.crawl_cycle , b.*
FROM $table a
INNER JOIN crawler_error_type b
ON a.error_type = b.error_type
INNER JOIN third_table c
ON a.error_type = c.error_type
WHERE a.projects_id = '$pid' AND
b.error_priority_page_level='High'.
If I understand it correctly, you should just be able to inner join the third table. Inner joins will on show the record if they have records in the joining tables. If I am misunderstanding could you please elaborate. Thx
select distinct (a.error_type),a.links_id, a.crawl_cycle , b.*
from $table a
inner join crawler_error_type b on a.error_type = b.error_type
inner join some_table_3 c on c.error_type = a.error_type
where a.projects_id = '$pid' and b.error_priority_page_level='High'
Related
I am working on a project where multiple table data exists for a user but if empty one table from any of them then SQL return empty data even other tables data exist like below SQL
$id = 40;
SELECT *
FROM players a
JOIN pitcher b
ON a.id = b.user_id
JOIN outfield_position c
ON a.id = c.user_id
JOIN infield_position d
ON a.id = d.user_id
JOIN defensive_statistics e
ON a.id = e.user_id
JOIN career f
ON a.id = f.user_id
WHERE a.id = $id
like if $outfield_position table is empty then the SQL returns an empty array but sometimes maybe data here, what can I do if data available or not available every way can works?
Thanks
The default join used is inner join and as already explained here joins .
The output in this case will be intersection of the tables it is joined with,so if any table does not have any value then intersection will give empty result.
You can try with LEFT OUTER JOIN or FULL OUTER JOIN , in Left Outer Join if data is present in $players the value will be displayed.If unsure about the data Full Outer join will give all the results from all the tables.
What I have been trying to achieve is to pull a price based on 3 different variables: brand_id, model_id, motor_id.
The design of the tables that I am working with:
The only issue is that when I add an INNER JOIN for databaseapp_lkp_prices I get a zero result set (fyi, there aren't any prices currently set so databaseapp_lkp_prices is an empty table)
I was expecting to see NULL in place of the price for the 48,000 records that exist when I don't add the databaseapp_lkp_prices INNER JOIN
My query is:
SELECT
a.brand,
b.model,
c.motor,
d.ecu_hardware_ver,
d.ecu_software_ver,
d.ecu_software_upg_ver,
d.ecu_brand,
d.ecu_type,
d.eprom,
d.eprom_desc,
d.`checksum`,
d.checksum16,
c.motor_hp * 1.2 AS motor_hp,
e.price,
c.motor_id,
c.model_id,
c.brand_id
FROM
databaseapp_brand AS a
INNER JOIN databaseapp_model AS b ON b.brand_id = a.brand_id
INNER JOIN databaseapp_motor AS c ON b.model_id = c.model_id
INNER JOIN databaseapp_ecu AS d ON d.motor_id = c.motor_id
INNER JOIN databaseapp_lkp_prices AS e ON c.brand_id = e.brand_id AND c.model_id = e.model_id AND c.motor_id = e.motor_id
ORDER BY
a.brand ASC,
b.model ASC
Anyone able to help me out with why I'm getting a zero result set when I try to look up the price.
Cheers!
Inner join requires match. No match no row. You should try LEFT JOIN instead of INNER JOIN for databaseapp_lkp_prices contribution.
I cannot solve this issue, I have tree tables, inner join and I'm after selecting only specific columns because I'm concerned about performance issue if I just leave SELECT * to do the job.
I have tables: ugovori-artikli, ugovori and ids, working SELECT * query:
SELECT * FROM `ugovori-artikli`
INNER JOIN `ugovori`
ON `ugovori-artikli`.`ugovor_id` = `ugovori`.`id`
INNER JOIN `ids`
ON `ugovori`.`kupac_id` = `ids`.`id`
AND `ugovori-artikli`.`artikal` = ?
and non-working query, my attempt:
SELECT a.*,
b.*,
c.id, c.ime, c.prezime
FROM `ugovori-artikli` AS a
INNER JOIN `ugovori` AS b
ON `ugovori-artikli`.`ugovor_id` = `ugovori`.`id`
INNER JOIN `ids` AS c
ON `ugovori`.`kupac_id` = `ids`.`id`
AND `ugovori-artikli`.`artikal` = ?
I get an error:
Error in query (1054): Unknown column 'ugovori-artikli.ugovor_id' in 'on clause'
Use the alias name
SELECT a.*,
b.*,
c.id, c.ime, c.prezime
FROM `ugovori-artikli` AS a
INNER JOIN `ugovori` AS b
ON a.`ugovor_id` = b.`id`
INNER JOIN `ids` AS c
ON b.`kupac_id` = c.`id`
AND a.`artikal` = ?
Hope this helps :)
You have to use the aliasses not the table name in your SQL statement.
SELECT a.*,b.*,c.id, c.ime, c.prezime
FROM `ugovori-artikli` AS a
INNER JOIN `ugovori` AS b ON a.`ugovor_id` = b.`id`
INNER JOIN `ids` AS c
ON b.`kupac_id` = cid`
AND a.`artikal` = ?
I am struggling to get this query to work . I have three tables and I want to do a query to get the red area.
Each circle is a table with different structure. I have managed a lot of combinations of inner joins but i specially cant get all the red areas.
A Payments : idPayment , idInvoice , Amount , date.
B Invoice : idInvoice , amount date.
C PromissoryNotes: IdNote , idInvoice, amount, date.
so far ...
SELECT B.idInvoice,A.idPayment,C.idNote FROM (Invoice b INNER JOIN payments a ON a.idInvoice=b.idInvoice) LEFT OUTER JOIN PromissoryNotes c ON c.idInvoice=b.idInvoice ORDER BY idInvoice.
DOESNT QUITE WORK
Any suggestions?
You were pretty close -- another OUTER JOIN and some WHERE criteria will do the trick:
SELECT B.idInvoice, A.idPayment, C.idNote
FROM Invoice b
LEFT JOIN payments a ON a.idInvoice=b.idInvoice
LEFT JOIN PromissoryNotes c ON c.idInvoice=b.idInvoice
WHERE a.idInvoice IS NOT NULL
OR c.idInvoice IS NOT NULL
ORDER BY B.idInvoice
What this basically says is give me all results from table B, where there's a match in table a or table c.
Condensed SQL Fiddle Demo
You could do this two ways:
1) Create a set A that is the inner join of B and A, create a set C that is the inner join of B and C, then union A and C.
2) Create a sub query that inner joins A and B, then full outer join to a sub query that inner joins C and B.
Example of 1)
SELECT b.idInvoice FROM Invoice B
JOIN Payments A on A.IdInvoice = B.IdInvoice
UNION
SELECT b.idInvoice FROM Invoice B
JOIN PromissoryNotes C on c.idInvoice = B.id Invoice
Example of 2)
SELECT idInvoice FROM
(
SELECT b.idInvoice FROM Invoice B
JOIN Payments A on A.IdInvoice = B.IdInvoice
) B FULL OUTER JOIN
(
SELECT b.idInvoice FROM Invoice B
JOIN Payments A on A.IdInvoice = B.IdInvoice
) C on b.idInvoice = C.idInvoice
Try
SELECT B.idInvoice, A.idPayment, C.idNote FROM Invoice B INNER JOIN payments A ON A.idInVoice = B.idInvoice INNER JOIN PromissoryNotes C ON C.idInvoice = B.idInvoice ORDER BY idInvoice
INNER JOIN means you get the intersection of both tables. So this is what you want.
Does this do the trick?
SELECT
ZZ.idInvoice,
ZZ.idPayment,
YY.idInvoice,
YY.idNote
FROM
(SELECT idInvoice, idPayment
FROM Invoice b
INNER JOIN payments a ON a.idInvoice=b.idInvoice) AS ZZ
FULL OUTER JOIN
(SELECT idInvoice, idNote
FROM PromissoryNotes c
INNER JOIN payments a ON a.idInvoice=c.idInvoice) AS YY ON ZZ.idInvoice = YY.idInvoice
SELECT p.idInvoice, p.idPayment, idNote
FROM Payments p JOIN Invoice i ON p.adInvoice-i.adInvoice RIGHT OUTER JOIN PromissoryNotes
UNION
SELECT i.idInvoice, idPayment, idNote
FROM Invoice i JOIN PromissoryNotes pn ON i.idInvoice=pn.idInvoice RIGHT OUTER JOIN Payments
You need to include the outer joins because the resulting tables that are to be unioned must have the same schema. I believe these are the desired fields from the query.
I'm having a real mind blank - This code selects rows quite nicely apart from those entries where I change st.station_id from a value of '1' to a different (but still valid) number but where there are no entries for that station_id in either the station_owner_map table, the organisation table or the cap_gen_data_table. I basically need to amend my sql to ignore any table where there are no entries.
Select st.station_id, st.station_name , st.st_town, st.st_state, c1.country_name, o1.organisation_name, som1.equity, st.river_basin, st.cost, st.cost_ref, st.comm_year,cg1.caporgen, ht1.hydro_name, cg1.value, srs1.srs_description, cg1.ref_year
FROM station st
inner join station_country_map scm1 on st.station_id = scm1.station_id
inner join country c1 on scm1.country_id = c1.country_id
inner join station_owner_map som1 on st.station_id = som1.station_id
inner join organisation o1 on som1.owner_id = o1.org_id
inner join cap_gen_data cg1 on st.station_id = cg1.station_id
inner join value_lookup vl1 on cg1.caporgen = vl1.id
inner join hydro_type ht1 on cg1.hydro_type_id = ht1.type_id
inner join station_record_status srs1 on cg1.capacity_status = srs1.st_rec_stat_id
where st.station_id = 1
It's caused by your inner joins. Inner join means there has to be a value in both tables for the record to show up in the result set.
Use left join instead, then only the table 'on the left' has to have a value.
Use left join on tables where the value may not be present.
If you have two tables A and B an inner join will only return the rows from A where the join condition is met. A left join will return all rows from A regardless of if the join condition is satisfied. Columns in the select statement associated with B will be null when a left join is used.
I have only added the left join to the tables you have indicated. If other tables may not satisfy the join condition change the join type from inner to left.
Select st.station_id, st.station_name , st.st_town, st.st_state, c1.country_name, o1.organisation_name, som1.equity, st.river_basin, st.cost, st.cost_ref, st.comm_year,cg1.caporgen, ht1.hydro_name, cg1.value, srs1.srs_description, cg1.ref_year
FROM station st
inner join station_country_map scm1 on st.station_id = scm1.station_id
inner join country c1 on scm1.country_id = c1.country_id
left join station_owner_map som1 on st.station_id = som1.station_id
left join organisation o1 on som1.owner_id = o1.org_id
left join cap_gen_data cg1 on st.station_id = cg1.station_id
inner join value_lookup vl1 on cg1.caporgen = vl1.id
inner join hydro_type ht1 on cg1.hydro_type_id = ht1.type_id
inner join station_record_status srs1 on cg1.capacity_status = srs1.st_rec_stat_id
where st.station_id = 1