Right now, I have
SELECT gp_id FROM gp.keywords
WHERE keyword_id = 15
AND (SELECT practice_link FROM gp.practices
WHERE practice_link IS NOT NULL
AND id = gp_id)
This does not provide a syntax error, however for values where it should return row(s), it just returns 0 rows.
What I'm trying to do is get the gp_id from gp.keywords where the the keywords table keyword_id column is a specific value and the practice_link is the practices table corresponds to the gp_id that I have, which is stored in the id column of that table.
I'm not even sure that is valid SQL, so I'm surprised it is working at all:
SELECT gp_id
FROM gp.keywords
WHERE keyword_id = 15
AND (SELECT practice_link FROM gp.practices WHERE practice_link IS NOT NULL AND id = gp_id)
How about this instead:
SELECT kw.gp_id, p.practice_link
FROM gp.keywords AS kw
INNER JOIN gp.practices AS p
ON p.id = kw.gp_id
WHERE kw.keyword_id = 15
I would steer clear of implicit joins as in the other examples. It only leads to tears later.
select k.gp_id
from gp.keywords as k,
gp.practices as p
where
keyword_id=15
and practice_link is not null
and p.id=k.gp_id
SELECT k.gp_id
FROM gp.keywords k, gp.practices p
WHERE
p.id = k.gp_id.AND
k.keyword_id = 15 AND
p.practice_link is not null
SELECT g.gp_id, p.practice_link FROM gp.keywords g, gp.practices p
WHERE
g.keyword_id = 15 AND p.practice_link IS NOT NULL AND p.id = g.gp_id
Related
When I add the nested query for invCount, my query time goes from .03 sec to 14 sec. The query works and I get correct values, but it is very, very slow in comparison. Is that just because I have to many conditions in that query? When I take it out and still have the second nested query, the time is still .03 secs. There is clearly something about the first nested query the database doesn't like, but I am not seeing what it is. I have a foreign key set for all the inner join lines too. Any help or ideas would be appreciated.
SELECT a.*,
f.name,
f.partNumber,
f.showInAdminStore,
f.showInPublicStore,
f.productImage,
r.mastCatID,
(SELECT COUNT(b.inventoryID)
FROM storeInventory b
INNER JOIN events c ON c.eventID = b.eventID
WHERE b.pluID = a.pluID
AND b.listPrice = a.listPrice
AND b.unlimitedQty = a.unlimitedQty
AND (b.packageID = a.packageID OR (b.packageID IS NULL AND a.packageID IS NULL))
AND b.orderID IS NULL
AND c.isOpen = '1'
AND b.paymentTypeID <= '2'
AND (b.inCart < '$cartTime' OR b.inCart IS NULL) ) AS invCount,
(SELECT COUNT(x.inventoryID)
FROM storeInventory x
WHERE x.packageID = a.inventoryID) AS packageCount
FROM storeInventory a
INNER JOIN storePLUs f ON f.pluID = a.pluID
INNER JOIN storeCategories r ON r.catID = f.catID
INNER JOIN events d ON d.eventID = a.eventID
WHERE a.storeFrontID = '1'
AND a.orderID IS NULL
AND a.paymentTypeID <= '2'
AND d.isOpen = '1'
GROUP BY a.packageID, a.unlimitedQty, a.listPrice, a.pluID
Table from query output
UPDATE: 12/12/2022
I changed the line checking the packageID to "AND (b.packageID <=> a.packageID)" as suggested and that cut my query time down to 7.8 seconds from 14 seconds. Thanks for the pointer. I will definitely use that in the future for NULL comparisons.
using "count(*)" took about half a second off. When I take the first nested query out, it drops down to .05 seconds even with the other nested queries in there, so I feel like there is still something causing issues. I tried running it without the other "AND (b.inCart < '$cartTime' OR b.inCart IS NULL)" line and that did take about a second off, but no where what I was hoping for. Is there an operand that includes NULL on a less than comparison? I also tried running it without the inner join in the nested query and that didn't change much at all. Of course removing any of that, throughs the values off and they become incorrect, so I can't run it that way.
Here is my current query setup that still pulls correct values.
SELECT a.*,
f.name,
f.partNumber,
f.showInAdminStore,
f.showInPublicStore,
f.productImage,
r.mastCatID,
(SELECT COUNT(*)
FROM storeInventory b
INNER JOIN events c ON c.eventID = b.eventID
WHERE b.pluID = a.pluID
AND b.listPrice = a.listPrice
AND b.unlimitedQty = a.unlimitedQty
AND (b.packageID <=> a.packageID)
AND b.orderID IS NULL
AND c.isOpen = '1'
AND b.paymentTypeID <= '2'
AND (b.inCart < '$cartTime' OR b.inCart IS NULL) ) AS invCount,
(SELECT COUNT(x.inventoryID)
FROM storeInventory x
WHERE x.packageID = a.inventoryID) AS packageCount
FROM storeInventory a
INNER JOIN storePLUs f ON f.pluID = a.pluID
INNER JOIN storeCategories r ON r.catID = f.catID
INNER JOIN events d ON d.eventID = a.eventID
WHERE a.storeFrontID = '1'
AND a.orderID IS NULL
AND a.paymentTypeID <= '2'
AND d.isOpen = '1'
GROUP BY a.packageID, a.unlimitedQty, a.listPrice, a.pluID
I am not familiar with the term 'Composite indexes' Is that something different than these?
Screenshot of ForeignKeys on Table a
I think
AND (b.packageID = a.packageID
OR (b.packageID IS NULL
AND a.packageID IS NULL)
)
can be simplified to ( https://dev.mysql.com/doc/refman/8.0/en/comparison-operators.html#operator_equal-to ):
AND ( b.packageID <=> a.packageID )
Use COUNT(*) instead of COUNT(x.inventoryID) unless you check for not-NULL.
The subquery to compute packageCount seems strange; you seem to count inventories but join on packages.
The need to reach into another table to check isOpen is part of the performance problem. If eventID is not the PRIMARY KEYforevents, then add INDEX(eventID, isOpen)`.
Some other indexes that may help:
a: INDEX(storeFrontID, orderID, paymentTypeID)
a: INDEX(packageID, unlimitedQty, listPrice, pluID)
b: INDEX(pluID, listPrice, unlimitedQty, orderID)
f: INDEX(pluID, catID)
r: INDEX(catID, mastCatID)
x: INDEX(packageID, inventoryID)
After OP's Update
There is no way to do (x<y OR x IS NULL) except by switching to a UNION. In your case, it is pretty easy to do the conversion. Replace
( SELECT COUNT(*) ... AND ( b.inCart < '$cartTime'
OR b.inCart IS NULL ) ) AS invCount,
with
( SELECT COUNT(*) ... AND b.inCart < '$cartTime' ) +
( SELECT COUNT(*) ... AND b.inCart IS NULL ) AS invCount,
Revised indexes:
storePLUs:
INDEX(pluID, catID)
storeCategories:
INDEX(catID, mastCatID)
events:
INDEX(isOpen, eventID)
storeInventory:
INDEX(pluID, listPrice, unlimitedQty, orderID, packageID)
INDEX(pluID, listPrice, unlimitedQty, orderID, inCart)
INDEX(packageID, inventoryID)
INDEX(storeFrontID, orderID, paymentTypeID)
I'm running a statement that's selecting stock market data from three tables. The last part of the statement is running a SELECT max(date) on a table that contains rows of stock data that is dated. I need the last date for a chosen stock from this table (tbl_asxd_extended.date). The problem is the statement just hangs and I can't work out why.
If I separate the statements, up to the final SELECT and run them independently they run fine! They just don't play well together when combined.
I'm not sure how to troubleshoot this one.
SELECT tbl_asxd_extended.close, tbl_asxd_extended.mcapintra, tbl_asxco.industry, tbl_asxco.company, tbl_watchlist.*
FROM tbl_watchlist
INNER JOIN tbl_asxco ON tbl_asxco.symbol = tbl_watchlist.symbol
INNER JOIN tbl_asxd_extended ON tbl_asxd_extended.symbol = tbl_watchlist.symbol
WHERE user_email='testuser#test.com'
AND tbl_asxd_extended.date =
(SELECT max(tbl_asxd_extended.date) FROM tbl_asxd_extended
WHERE tbl_watchlist.symbol = tbl_asxd_extended.symbol)
Here is an 'EXPLAIN' of the statement
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY tbl_watchlist ALL NULL NULL NULL NULL 9 Using where
1 PRIMARY tbl_asxco eq_ref symbol_2,symbol symbol_2 32 func 1 Using where
1 PRIMARY tbl_asxd_extended ALL NULL NULL NULL NULL 2195 Using where; Using join buffer
2 DEPENDENT SUBQUERY tbl_asxd_extended ALL NULL NULL NULL NULL 2195 Using where
SELECT tbl_asxd_extended.close, tbl_asxd_extended.mcapintra, tbl_asxco.industry, tbl_asxco.company, tbl_watchlist.*
FROM tbl_watchlist
INNER JOIN tbl_asxco ON tbl_asxco.symbol = tbl_watchlist.symbol
INNER JOIN tbl_asxd_extended ON tbl_asxd_extended.symbol = tbl_watchlist.symbol
WHERE user_email='testuser#test.com'
AND tbl_asxd_extended.date =
(SELECT MAX(tbl_asxd_extended.date) FROM tbl_asxd_extended
WHERE tbl_watchlist.symbol = tbl_asxd_extended.symbol)
this will solve your problem as you're using the max() instead of MAX();
And if possible execute last select query first and store it in any variable say result and just assign result variable to the AND part condition matching
An uncorrelated subquery usually outperforms a correlated one:
SELECT e.close
, e.mcapintra
, s.industry
, s.company
, w.*
FROM tbl_watchlist w
JOIN tbl_asxco a
ON a.symbol = w.symbol
JOIN tbl_asxd_extended e
ON e.symbol = w.symbol
JOIN
( SELECT symbol
, MAX(date) date
FROM tbl_asxd_extended
GROUP
BY symbol
) x
ON x.symbol = e.symbol
AND x.date = e.date
WHERE user_email = 'testuser#test.com'
Further performance improvements may be gained by providing the EXPLAIN for the above together with CREATE TABLE statements for ALL relevant tables.
I have query like this:
SELECT cs_event.*, cs_file.name, cs_file.extension, cs_user.first_name, cs_user.last_name
FROM cs_event
LEFT JOIN cs_file ON cs_event.idfile = cs_file.idfile
LEFT JOIN cs_user ON cs_event.iduser = cs_user.iduser
WHERE type != 51
AND idportal = 1
UNION DISTINCT
SELECT cs_event.*, cs_file.name, cs_file.extension, cs_user.first_name, cs_user.last_name
FROM cs_event
LEFT JOIN cs_file ON cs_event.idfile = cs_file.idfile
LEFT JOIN cs_user ON cs_event.iduser = cs_user.iduser
WHERE shared_with_users LIKE '%i:2;%'
AND idportal = 1
ORDER BY add_date DESC
LIMIT 6
The problem is following:
Regular user can't see certain types of events (for now it is type 51) and he can see only things which are shared with him.
shared_with_users column can be null or have value - this column have value only for one type of event (type = 50) and for other events it is null.
I need to perform following:
User can access all events except event with type 51 and if the the event is type of 50, I need to check if the event is shared with him (shared_with_users column), and collect that also. Is it possible to make this kind of query?
Try this
SELECT cs_event.*, cs_file.name, cs_file.extension, cs_user.first_name, cs_user.last_name
FROM cs_event
LEFT JOIN cs_file ON cs_event.idfile = cs_file.idfile
LEFT JOIN cs_user ON cs_event.iduser = cs_user.iduser
WHERE type != 51 o or (type = 50 and shared_with_users LIKE '%i:2;%')
AND idportal = 1
ORDER BY add_date DESC
LIMIT 6
I think you can do this as a single query, with logic in the WHERE clause:
SELECT e.*, f.name, f.extension, u.first_name, u.last_name
FROM cs_event e LEFT JOIN
cs_file f
ON e.idfile = f.idfile LEFT JOIN
cs_user u
ON e.iduser = u.iduser
WHERE idportal = 1 AND
(type <> 51 OR shared_with_users LIKE '%i:2;%');
Some notes:
I don't think the LEFT JOINs are necessary. The WHERE clause may be turning them into inner joins anyway, but it is hard to tell without qualified column names.
I added table aliases so the query is easier to write and to read.
The logic for shared_with_users suggests that you have stored a list of values in a string. That is a bad choice.
I'm wanting to do the following:
Select everything from product that matches the value of type_id from both tables product and system_type. Then with those matched results, match cat_id from both tables system_type and system_cat and then refine the final result where cat_type = 0 from the system_cat table.
Current SQL seems to have a syntax error:
SELECT * FROM product
JOIN system_type
USING (type_id)
JOIN system_cat
USING (cat_id)
WHERE cat_type = 0
What else I've tried:
SELECT * FROM product
JOIN system_type
USING system_type.type_id = product.type_id
JOIN system_cat
USING system_type.cat_id = system_cat.cat_id
WHERE system_cat.cat_type = 0
Try this. You may need to explicitely type out the columns you need
SELECT * FROM product as pr
INNER JOIN system_type as st
ON st.type_id = pr_id
INNER JOIN system_cat as sc
ONH st.cat_id = sc.cat_id
WHERE sc.cat_type = 0
Syntax changes when using table_name.column method. Use ON and not USING.
SELECT * FROM product
JOIN system_type
ON system_type.type_id = product.type_id
JOIN system_cat
ON system_type.cat_id = system_cat.cat_id
WHERE system_cat.cat_type = 0
I have a short access/mySQL question. I have a mapping table on the format below.
ID Category_A Category_B Category_C Team
1 a b T1
2 a d T2
I have a second table which also includes Category_A, Category_B, and Category_C. I would like to join the Team value to the my second table based on the mappingtable. My problem is that when there is a blank (e.g. ID=2, Category_B) the mapping should assign the T2 to any row that contains Category_A=a and Category_C=d regardless of the value in Category_B.
Can this type of mapping be done?
Grateful for your help!
In MS Access, I think you would need something on the lines of:
SELECT t.ID, m.Team
FROM Team t
INNER JOIN Mapping m
ON (m.Category_C = t.Category_C)
AND (m.Category_B = t.Category_B)
AND (m.Category_A = t.Category_A)
WHERE m.Category_C Is Not Null
AND m.Category_B Is Not Null
AND m.Category_A Is Not Null
UNION ALL
SELECT t.ID, m.Team
FROM Team t
INNER JOIN Mapping m
ON (m.Category_B = t.Category_B)
AND (m.Category_A = t.Category_A)
WHERE m.Category_C Is Null
AND m.Category_B Is Not Null
AND m.Category_A Is Not Null
UNION ALL
SELECT t.ID, m.Team
FROM Team t
INNER JOIN Mapping m
ON (m.Category_C = t.Category_C)
AND (m.Category_A = t.Category_A)
WHERE m.Category_C Is Not Null
AND m.Category_B Is Null
AND m.Category_A Is Not Null
UNION ALL
SELECT t.ID, m.Team
FROM Team t
INNER JOIN Mapping m
ON (m.Category_C = t.Category_C)
AND (m.Category_B = t.Category_B)
WHERE m.Category_C Is Not Null
AND m.Category_B Is Not Null
AND m.Category_A Is Null