I have a query like below. This query is working fine but since I have huge amount of data to check, this query running is slower.
Can anybody help me how to optimize this query?
SELECT * from trn where concat(comp_id,cus_id)
IN (select concat(comp_id,cus_id) FROM cus where sid='A0001')
AND docdate between ('2018-01-01') and ('2018-04-30')
The concat is probably causing those performance problems as it can't use indexes.
But MySQL supports multi-column subqueries, so simply remove it:
SELECT * from trn
where (comp_id,cus_id) IN
( select comp_id,cus_id
FROM cus
where sid='A0001'
)
AND docdate between ('2018-01-01') and ('2018-04-30')
You can use JOIN, e.g.:
SELECT DISTINCT t.*
FROM trn t
JOIN cus c ON t.comp_id = c.comp_id AND t.cus_id = c.cus_id
WHERE c.sid='A0001' AND t.docdate BETWEEN ('2018-01-01') AND ('2018-04-30');
You can use EXISTS :
SELECT t.*
FROM trn t
WHERE EXISTS (SELECT 1
FROM cus c
WHERE c.sid = 'A0001' AND c.comp_id = t.comp_id AND c.cus_id = t.cus_id
) AND
docdate between '2018-01-01' and '2018-04-30';
Related
I would like to optimise the query I have below:
SELECT
a.id, a.pay_point_name, a.pay_point_location,
COUNT(b.id) AS countedCustomers,
SUM(b.approved) AS summedLoans,
SUM(c.deduction) AS summedDeductions
FROM
pay_tbl a
LEFT JOIN
customer_tbl b
ON b.employer = a.pay_point_name
LEFT JOIN
loans_tbl c
ON c.paypoint = a.pay_point_name
GROUP BY
a.pay_point_name
ORDER BY
NULL
Current Execution time: 161.2s
EXPLAIN statement gives me the table below:
I would like to know how best to optimise this query and reduce execution time.
Please check this one where I've used subquery. If this works better create view with this query.
-- MySQL
SELECT t.id, t.pay_point_name
, t.pay_point_location
, COALESCE(t.countedCustomers, 0) countedCustomers
, COALESCE(t.summedLoans, 0) summedLoans
, COALESCE(p.summedDeductions, 0) summedDeductions
FROM (SELECT a.id, a.pay_point_name
, MAX(a.pay_point_location) pay_point_location
, COUNT(b.id) AS countedCustomers
, SUM(b.approved) AS summedLoans
FROM pay_tbl a
LEFT JOIN customer_tbl b
ON b.employer = a.pay_point_name
GROUP BY a.id, a.pay_point_name) t
LEFT JOIN (SELECT paypoint
, SUM(deduction) AS summedDeductions
FROM loans_tbl
GROUP BY paypoint) p
ON t.pay_point_name = p.paypoint
ORDER BY t.id;
Suppose if you have to repeatedly execute the same query frequently. You can use MySql views.
https://www.mysqltutorial.org/mysql-views-tutorial.aspx
I have been having some troubles getting my head around achieving the below.
I have an 'applications' table and a 'application_logs' table. I am attempting to select all the applications where the 'type' is equal to 'test' and then join the 'application_logs' table and retrieve only the first log entry for the application.
One of the queries I tried and understood most was: (whilst this didn't fail it looked like an endless loop and completed the query.
SELECT applications.id FROM applications JOIN application_logs ON application_logs.application_id =
(
SELECT application_logs.id FROM application_logs
WHERE application_logs.application_id = applications.id
ORDER BY id DESC
LIMIT 1
)
WHERE type = 'test';
There were some other queries (using CROSS APPLY/distinct) I attempted but they didn't make sense to me and didn't look like they were trying to achieve the same thing. I appreciate all the help :)
There are many ways to achieve this in standard SQL. A lateral join (CROSS APPLY) is the first to come to mind, but MySQL doesn't support it. Another would be FETCH FIRST ROWS WITH TIES to get all latest application logs, but MySQL doesn't support it (and its counterpart LIMIT doesn't have a ties clause either). If you are only interested in the application ID alone (as shown in your query) one could even combine this with an INTERSECT operation, but MySQL doesn't support it.
After all you want to find out the maximum log ID per application ID. As of MySQL 8 you can do this on-the-fly:
select *
from applications a
left join
(
select
application_logs.*,
max(id) over (partition by application_id) as max_application_id
from application_logs
) al on al.application_id = a.id and al.application_id = al.max_application_id
where a.type = 'test';
In earlier vesions you would do this in separate steps. One way would be this:
select *
from applications a
left join application_logs al
on al.application_id = alm.application_id
and (al.application_id, al.id) in
(
select application_id, max(id)
from application_logs
group by application_id
)
where a.type = 'test';
Another is your own query, where you only got confused with the IDs:
SELECT *
FROM applications a
JOIN application_logs al ON al.id =
(
SELECT almax.id
FROM application_logs almax
WHERE almax.application_id = a.id
ORDER BY almax.id DESC
LIMIT 1
)
WHERE a.type = 'test';
try this
SELECT
a.*, c.*
FROM
applications a
INNER JOIN (
SELECT
al.application_id AS application_id,
MAX(al.id) AS al_id
FROM
application_logs al
GROUP BY
al.application_id
) c ON a.id = c.application_id
WHERE
a.type = 'test';
To get the first entry from application_logs table with respect to application_id. You need to use Row_Number Over (partition by order by ).
SELECT *
FROM applications A
LEFT JOIN (
SELECT Id AS applications.id
FROM (
SELECT ROW_NUMBER() OVER (Partition By applications.id ORDER BY application_logs.id) as R, application_logs.id, applications.id
FROM application_logs
) AS S
WHERE R = 1
) AS L ON L.applications.id = A.applications.id
Try this -
SELECT a.id, ay.*
FROM applications AS a
INNER JOIN (
SELECT al.application_id, min(al.id) as Min_Id
FROM application_logs AS al
GROUP BY al.application_id
) AS ax ON ax.application_id = a.id
INNER JOIN application_logs AS ay ON ay.id = ax.id
WHERE a.type = 'test';
Your query suggests that "first" means the largest id. (Colloquially, I would expect "first" to mean the smallest id or earliest chronologically.)
I usually recommend a correlated subquery for the filtering. It is worth testing if this is faster than other methods:
select . . .
from applications a join
application_logs al
on al.application_id = a.id
where a.type = 'test' and
al.id = (select max(al2.id)
from application_logs al2
where al2.application_id = al.application_id
);
The optimal indexes for performance are:
application(type, id)
application_logs(application_id, id)
I need assistance in joining the two query statements together using subquery. I am confused on how I can combine the two together. I appreciate the help.
SELECT * FROM MEDICAL_PROCEDURE
JOIN PROCEDURE_CATEGORY ON medical_procedure.procedure_category_id = PROCEDURE_CATEGORY.PROCEDURE_CATEGORY_ID;
SELECT
Medical_procedure.medical_procedure_id,
COUNT(procedure_tool_supply.medical_procedure_id) AS Supply_Needed
FROM Procedure_tool_supply
JOIN Medical_Procedure on Procedure_tool_supply.medical_procedure_id = Medical_procedure.medical_procedure_id
GROUP BY Procedure_tool_supply.medical_procedure_id
HAVING COUNT(Procedure_tool_supply.medical_procedure_id) < 3;
Can't really test without test data, but this should work. Hopefully I figured out correctly what you're trying to do:
SELECT *
FROM
MEDICAL_PROCEDURE P
JOIN PROCEDURE_CATEGORY C ON
P.procedure_category_id = C.PROCEDURE_CATEGORY_ID
cross apply (
SELECT
COUNT(T.medical_procedure_id) AS Supply_Needed
FROM
Procedure_tool_supply T
where
T.medical_procedure_id = P.medical_procedure_id
GROUP BY
T.medical_procedure_id
HAVING
COUNT(T.medical_procedure_id) < 3
) T
It's not clear what you are trying to achieve. But if your intent is to include the derived Supply_Needed column from the second query on each row from the first query, and to restrict the rows returned to those that have a medical_procedure_id value returned by the second query, then...
you could do something like this:
SELECT mp.*
, pc.*
, ct.Supply_Needed
FROM MEDICAL_PROCEDURE mp
JOIN PROCEDURE_CATEGORY pc
ON mp.procedure_category_id = pc.PROCEDURE_CATEGORY_ID
JOIN ( SELECT pr.medical_procedure_id
, COUNT(ts.medical_procedure_id) AS Supply_Needed
FROM Procedure_tool_supply ts
JOIN Medical_Procedure pr
ON ts.medical_procedure_id = pr.medical_procedure_id
GROUP BY ts.medical_procedure_id
HAVING COUNT(ts.medical_procedure_id) < 3
) ct
ON ct.medical_procedure_id = mp.medical_procedure_id
While working with following query on mysql, Its getting locked,
SELECT event_list.*
FROM event_list
INNER JOIN members
ON members.profilenam=event_list.even_loc
WHERE (even_own IN (SELECT frd_id
FROM network
WHERE mem_id='911'
GROUP BY frd_id)
OR even_own = '911' )
AND event_list.even_active = 'y'
GROUP BY event_list.even_id
ORDER BY event_list.even_stat ASC
The Inner query inside IN constraint has many frd_id, So because of that above query is slooow..., So please help.
Thanks.
Try this:
SELECT el.*
FROM event_list el
INNER JOIN members m ON m.profilenam = el.even_loc
WHERE el.even_active = 'y' AND
(el.even_own = 911 OR EXISTS (SELECT 1 FROM network n WHERE n.mem_id=911 AND n.frd_id = el.even_own))
GROUP BY el.even_id
ORDER BY el.even_stat ASC
You don't need the GROUP BY on the inner query, that will be making the database engine do a lot of unneeded work.
If you put even_own = '911' before the select from network, then if even_own IS 911 then it will not have to do the subquery.
Also why do you have a group by on the subquery?
Also run explain plan top find out what is taking the time.
This might work better:
( SELECT e.*
FROM event_list AS e
INNER JOIN members AS m ON m.profilenam = e.even_loc
JOIN network AS n ON e.even_own = n.frd_id
WHERE n.mem_id = '911'
AND e.even_active = 'y'
ORDER BY e.even_stat ASC )
UNION DISTINCT
( SELECT e.*
FROM event_list AS e
INNER JOIN members AS m ON m.profilenam = e.even_loc
WHERE e.even_own = '911'
AND e.even_active = 'y' )
ORDER BY e.even_stat ASC
Since I don't know whether the JOINs one-to-many (or what), I threw in DISTINCT to avoid dups. There may be a better way, or it may be unnecessary (that is, UNION ALL).
Notice how I avoid two things that are performance killers:
OR -- turned into UNION
IN (SELECT...) -- turned into JOIN.
I made aliases to cut down on the clutter. I moved the ORDER BY outside the UNION (and added parens to make it work right).
I have query that working perfectly.but now there is situation where i have to join 2 query in case statement.but problem is one of the query is in already use.So my question how do i add this two sql in one sql
My original sql is
SELECT
tc.dentist_id,md.vendor_no,pl.pack_trans_id,tc.agent_dentist,md.company_name,md.contact,md.phone_no,sql1.image_path,sql1.metal_id,sql1.expect_more,sql1.how_long_acquire,tc.check_amt,tc.check_date_sent,tc.check_no
FROM tbl_check tc
LEFT JOIN tbl_mst_dentist md ON tc.dentist_id=md.dentist_id
LEFT JOIN tbl_pack_list pl ON tc.pack_id=pl.pack_id
LEFT JOIN (SELECT image_path,pack_id,metal_id,expect_more,how_long_acquire FROM
tbl_metals_list GROUP BY pack_id
)sql1 ON tc.pack_id=sql1.pack_id
WHERE tc.sale_agent_id = '3' AND tc.paying_percent !=0
Now i have to add 2 sql statement in the above statement
if(tc.agent_dentist=a) select sa.* ,sm.state_code from tbl_sales_agent
as sa,tbl_mst_state as sm where sa.sales_agent_id = '3' AND
sa.state=sm.state_name else select * from tbl_mst_dentist where
dentist_id =tc.dentist_id
second table already is in use.Is it possible? Thanks in advance
yes, you can use an ALIAS with a different name. E.g. TABLE AS ANY_ALIAS.
SELECT *
FROM t1
JOIN t2 AS alias_a ON (alias_a.t1_id = t1.id)
JOIN t2 AS alias_b ON (alias_b.t1_id = t1.id)
Note that in the absence of any aggregating functions, the use of GROUP BY in this query...
SELECT image_path
, pack_id
, metal_id
, expect_more
, how_long_acquire
FROM tbl_metals_list
GROUP
BY pack_id
...makes little sense. Perhaps you meant SELECT DISTINCT...?