I have a query like this:
DELETE FROM rules_table
WHERE
type1 = (
SELECT type_id
FROM types_table
WHERE name = '<some_name>')
OR
type2 = (
SELECT type_id
FROM types_table
WHERE name = '<some_name>')
Please note that <some_name> is the same in both occurrences
I submit a query from php script and I'd prefer it to be a single request rather then selecting the type_is with one request, parsing the result and submitting the delete request.
And also as far as I know, running the same SELECT statement two times is also a bad idea.
try
DELETE FROM rules_table
WHERE (
SELECT type_id
FROM types_table
WHERE name = '<some_name>'
) in (type1, type2)
instead of subquery you can use INNER JOIN:
DELETE a
FROM rules_table a
INNER JOIN types_table b
ON (a.type1 = b.type_id OR a.type2 = b.type_id)
WHERE b.name = '<some_name>';
Related
review table has store_idx, user_idx etc...
I want to create a query sentence that gets information about the store to which the user has bookmarked with the user_id value entered.
The query sentence I made is
select A.store_name
, A.store_img
, count(B.store_idx) as review_cnt
from board.store A
Left
Join board.review B
On A.store_idx is B.store_idx
where store_idx is (select A.store_idx from bookmark where user_id = ?)
However, nothing came out as a result.
Help me..
Please use below Query:
SELECT store_name
, store_img
, SUM(review_cnt) AS review_cnt
FROM
( SELECT DISTINCT A.store_name
, A.store_img
, CASE WHEN B.store_idx IS NULL THEN 0 ELSE 1 END AS review_cnt
FROM bookmark br
JOIN board.store A
ON A.store_idx = br.store_idx
LEFT
JOIN board.review B
ON A.store_idx = B.store_idx
WHERE br.user_id = ?
)T
The WHERE clause is obviously filtering out all rows. We can't do much about that. But your query is also lacking a GROUP BY, the table aliases can be improved, and the join condition is not correct.
So, try this version:
select s.store_name, s.store_img, count(b.store_idx) as review_cnt
from board.store s left join
board.review r
on s.store_idx = r.store_idx
where b.store_idx in (select b.store_idx
from bookmark b
where b.user_id = ?
);
If have a db table name WORK with this data
Client|Task |Status
A |Clean office |Done
A |Paint the wall|Issue
A |Read mail |Done
B |Fix PC |Done
B |Buy Parts |Done
My query is
SELECT * FROM `WORK` where Status = "Done"
I want to show only task that done, but if client have records that is not "Status = Done", I don't want to get neither of his records (Even those who have Status done)
And I would get only two client B records because all of them done.
You can use NOT IN() function for this :
SELECT * FROM `Work` t
WHERE t.Client NOT IN(SELECT distinct s.Client FROM `Work` s
WHERE s.status <> 'Done')
That way you select only those that have only 'Done' status.
You can also do that using a LEFT JOIN like this:
SELECT * FROM `work` t
LEFT JOIN(SELECT * from `work` where status <> 'Done') s
ON(t.Client = s.Client)
WHERE s.Client is null
you can use NOT IN in this way:
select * from Work where status='Done' and Client NOT IN(SELECT DISTINCT Client FROM Work
WHERE status != 'Done');
I'm trying to select and group by all the contentid values of the table below where the match criteria can be several different values.
the contentid values actually represent cars, so I need to select [and group by] all the contentis where the values are 'GMC' and the values are 'sedan' and the value is 'automatic.
i.e. I'm trying to select all the GMC sedans with an automatic transmission.
a query like this fails [obviously]:
select * from modx_site_tmplvar_contentvalues WHERE
`value` = 'gmc' and
`value` = 'tacoma'
group by contentid
I have no idea how to create a query like that. Any suggestions?
You need to "pivot" these data on "tmplvarid", but unfortunately for you MySQL doesn't have a PIVOT statement like other RDBMS. However, you can pivot it yourself by joining in the table multiple times for each variable you care about:
SELECT
contents.contentid,
transmission.value as transmission,
type.value as type,
make.value as make
FROM
(SELECT DISTINCT contentid FROM modx_site_tmplvar_contentvalues) AS contents
LEFT JOIN
modx_site_tmplvar_contentvalues AS transmission
ON contents.contentid = transmission.contentid
AND transmission.tmplvarid = 33 -- id for transmission
LEFT JOIN
modx_site_tmplvar_contentvalues AS make
ON contents.contentid = make.contentid
AND make.tmplvarid = 13 -- id for make
LEFT JOIN
modx_site_tmplvar_contentvalues AS type
ON contents.contentid = type.contentid
AND type.tmplvarid = 17 -- id for type
WHERE
type.value = 'sedan'
AND make.value = 'GMC'
AND transmission.value = 'automatic'
You can expand this with additional joins for other criteria such as year (id 15) or mileage (id 16).
If you need to use the value only, you could try:
SELECT DISTINCT
contents.contentid,
transmission.value as transmission,
type.value as type,
make.value as make
FROM
(SELECT DISTINCT contentid FROM modx_site_tmplvar_contentvalues) AS contents
INNER JOIN
modx_site_tmplvar_contentvalues AS transmission
ON contents.contentid = transmission.contentid
AND transmission.value = 'automatic'
INNER JOIN
modx_site_tmplvar_contentvalues AS make
ON contents.contentid = make.contentid
AND make.value = 'GMC'
INNER JOIN
modx_site_tmplvar_contentvalues AS type
ON contents.contentid = type.contentid
AND type.value = 'sedan'
In any case, make sure you have an index on the value column; these queries are going to get slow.
please try this:
SELECT *
FROM modx_site_tmplvar_contentvalues t1 INNER JOIN modx_site_tmplvar_contentvalues t2 ON t1.contentid = t2.content_id
WHERE
t1.`value` = 'gmc'
AND t2.`value` = 'tacoma';
You can do this with a group by. This is the most flexible in terms of expressing the conditions. In MySQL, multiple joins will often perform better:
select contentid
from modx_site_tmplvar_contentvalues
group by contentid
having sum(`value` = 'gmc') > 0 and
sum(`value` = 'tacoma') > 0;
This is always false:
`value` = 'gmc' and
`value` = 'tacoma'
Instead, use OR:
`value` = 'gmc' OR
`value` = 'tacoma'
In a condition "and" means "this and this is true at the same time". If you want all foos and all bars, then your condition is "foo OR bar".
EDIT:
To select groups containing your values, you can write subqueries:
SELECT DISTINCT name FROM table WHERE name IN (SELECT name FROM table WHERE value='value1') AND name IN (SELECT name FROM table WHERE value='value2')
I have two tables:
objects object_features
------------- -------------------
id id
name object_id
term_id
What I want to achieve is, giving a list of features, get all objects that has all of them.
I'm trying this:
SELECT objects.*
FROM `object_features` LEFT JOIN `objects` ON ( objects.id=object_features.object_id)
WHERE term_id IN ('1','3','4','10')
This is the php code I'm using:
$feature_list = array(1,3,4,10);
$sql = 'SELECT objects.*
FROM `object_features` LEFT JOIN `objects` ON ( objects.id=object_features.object_id)
WHERE term_id IN ('.implode(',', $feature_list).')';
This is near to what I need, but differing that it returns me any object that has any of the features given, instead of ALL the features
one option is to group by the data you want returned from object and add a having clause that counts object.id and tests to see if it is the same as the length of the array.
SELECT objects.id, objects.name
FROM `object_features` LEFT JOIN `objects` ON ( objects.id=object_features.object_id)
WHERE term_id IN ('1','3','4','10')
group by objects.id,objects.name
having count(objects.id) = 4
Cant swear to the syntax on that as I've been writing tsql recently and don't have an instance of mysql to test on.
try
'WHERE term_id = '.impode(' AND termid = ', $features_ids).')'
This will result in:
WHERE termid = 1 AND termid = 3 AND termid = 5
Actually you need a GROUP BY to group by each object and using a HAVING clause to allow only rows that have all the termids
SELECT objects.*
FROM `object_features` LEFT JOIN `objects` ON ( objects.id=object_features.object_id)
WHERE term_id IN ('1','3','4','10')
GROUP BY objects.id, objects.name
HAVING count(term_id) = 4
The SQL way of doing it would be:
SELECT objects.*
FROM objects
WHERE null not in
(
select of.object_id
from features f
left join object_features of on (f.id = of.id)
)
Assuming you have a features table with all the features.
If you need to list only certain features, you can do (check out the where condition on the subquery):
SELECT objects.*
FROM objects
WHERE null not in
(
select of.object_id
from features f
left join object_features of on (f.id = of.id)
where f.id in (1,2,3,4,5)
)
I have a master table called "parent" and a related table called "childs"
Now I run a query against the master table to update some values with the sum from the child table like this.
UPDATE master m SET
quantity1 = (SELECT SUM(quantity1) FROM childs c WHERE c.master_id = m.id),
quantity2 = (SELECT SUM(quantity2) FROM childs c WHERE c.master_id = m.id),
count = (SELECT COUNT(*) FROM childs c WHERE c.master_id = m.id)
WHERE master_id = 666;
Which works as expected but is not a good style because I basically make multiple SELECT querys on the same result. Is there a way to optimize that? (Making a query first and storing the values is not an option.
I tried this:
UPDATE master m SET (quantity1, quantity2, count) = (
SELECT SUM(quantity1), SUM(quantity2), COUNT(*)
FROM childs c WHERE c.master_id = m.id
) WHERE master_id = 666;
but that doesn't work.
Update: Here is the solution, thanks to everbody:
You can do something like this:
UPDATE master m
INNER JOIN childs c ON m.master_id = c.master_id
SET master.quantity1 = c.quantity1,
master.count = 1
If you have only one child record at a time. However if you want to use a group function like SUM() in the joined table that doesn't work. Either you get a "Invalid use of group function" if you leave the "group by" part or a "You have an error in your sql syntax if you use "GROUP BY c.master_id"
-- This doesnt work :(
UPDATE master m
INNER JOIN childs c ON m.master_id = c.master_id
SET master.quantity1 = SUM(c.quantity1),
master.count = COUNT(c.*)
GROUP by c.master_id
The solution is to use JOIN with a subquery:
UPDATE master m
INNER JOIN
(
SELECT master_id,
SUM(quantity1) as quantity1,
COUNT(*) as count
FROM childs c
GROUP BY master_id
) c
ON c.master_id = m.master_id
SET m.quantity1 = c.quantity1,
m.count = c.count
WHERE m.master_id = 666;
But since this pulls every row from the childtable the overhead would likely be bigger than using more subqueries like in the original sql. So you should add a WHERE clause to the joined table to get only the rows you need.
Another interesting approach is this syntax, which does the same as the JOIN with the WHERE clause but you should only use if if you want to update all rows with the same values and your subquery only returns one row, since the result from the subquery gets appended to the result and can be used like any column.
UPDATE master m,
(
SELECT SUM(c.quantity1) as sum_of_quantity,
COUNT(*) as rowcount FROM child c WHERE c.master_id = 666
) as c
SET m.quantity1 = c.sum_of_quantity,
m.count = c.rowcount
WHERE m.master_id = 666;
Rewriting Lieven's solution to MySQL:
UPDATE master m
JOIN (
SELECT master_id
, SUM(quantity1) as quantity1
, SUM(quantity2) as quantity2
, COUNT(*) as count
FROM childs c
GROUP BY
master_id
) c
ON c.master_id = m.master_id
SET
m.quantity1 = c.quantity1
,m.quantity2 = c.quantity2
,m.count = c.count
WHERE m.master_id = 666;
I don't know if it is allowed in MySQL, but SQL Server allows you to use the result of a select in an update.
UPDATE master m SET
quantity1 = c.quantity1
, quantity2 = c.quantity2
, count = c.count
FROM master m
INNER JOIN (
SELECT master_id
, quantity1 = SUM(quantity1)
, quantity2 = SUM(quantity2)
, count = COUNT(*)
FROM childs c
WHERE master_id = 666
GROUP BY
master_id
) c ON c.master_id = m.master_id
You could select your data into a temporary table, and then update using that data.
If you also want to insert "new" data in the same roundtrip, look into INSERT INTO ... SELECT FROM ... ON DUPLICATE KEY UPDATE ...
If you already are doing inserts if row doesn't exist, then that would be redundant with this example.
example:
INSERT INTO master m (id, quantity1, quantity2, count)
SELECT master_id, SUM(quantity1) q1, SUM(quantity2) q1, COUNT(*) c
FROM childs
GROUP BY master_id
ON DUPLICATE KEY UPDATE
m.quantity1 = q1,
m.quantity2 = q2,
m.count = c
NOTE! This is untested code, but I think it should be possible to backreference the select result in the UPDATE.
Syntax reference: http://dev.mysql.com/doc/refman/5.0/en/insert.html