Im trying to run a sub-query that based on one of the main query values but i always get 0 as VALUE.
This is my query :
SELECT ID,(
SELECT COUNT( * )
FROM `post_meta`
WHERE `post_id`
IN (
SELECT `ID`
FROM `wp_posts`
WHERE `post_title` = posts.ID
)
) AS counter
FROM wp_posts;
if i run only the sub-query with id number instead of posts.ID it returns a good value.
I do believe a simple join in the sub query will get you the correct COUNT:
SELECT posts.ID,
(
SELECT COUNT(*)
FROM post_meta
INNER JOIN wp_posts ON wp_posts.ID = post_meta.post_ID
WHERE wp_posts.post_title = posts.ID
) AS counter
FROM posts;
The problem was fixed by giving the table a custom name so i can use it when im going in two layers this is how the code look after the change :
SELECT ID,(
SELECT COUNT( * )
FROM `post_meta`
WHERE `post_id`
IN (
SELECT `ID`
FROM `wp_posts`
WHERE `post_title` = my_posts.ID
)
) AS counter
FROM wp_posts as my_posts;
Linger you beat me to it but I was going to suggest leaving out the subquery altogether if I can guess what the structure looks like.
SELECT ID, COUNT(*) AS count FROM wp_posts
INNER JOIN post_meta ON wp_posts.ID = post_meta.post_id
WHERE wp_posts.ID = post_title
GROUP BY ID
OR
SELECT COUNT(*) AS count FROM wp_posts
INNER JOIN post_meta ON wp_posts.ID = post_meta.post_id
WHERE wp_posts.ID = post_title
Related
SELECT post_title,
count(*) AS c
FROM wp_posts
WHERE post_type = "product"
GROUP BY post_title
HAVING c > 1
ORDER BY c DESC
runs no problem, returns result in < 1 sec. Yet
select * from wp_posts where post_title in (
select post_title from wp_posts WHERE post_type = "product"
group by post_title having count(*) > 1
)
hangs up.
Yet they are fundamentally the same query except for the fact that in the second query I'm trying to pull out the entire record rather than just the post_title.
Have I erred? Is there a more efficient way to achieve the equivalent?
Edit: EXPLAIN query and SHOW CREATE TABLE wp_posts has been appended for your information.
you could avoid the IN clause on the subquery and use an inner join
select a.*
from wp_posts a
INNER JOIN (
select post_title
from wp_posts
WHERE post_type = "product"
group by post_title
having count(*) > 1
) t ON t.post_title = a.post_title
this should be more performant
The most efficient way to write this query is probably using exists . . . assuming wp_posts has a primary key:
select p.*
from wp_posts p
where p.post_type = 'product' and
exists (select 1
from wp_posts p2
where p2.post_title = p.post_title and
p2.post_type = p.post_type and
p2.id <> p.id
);
For performance, yu want an index on wp_posts(post_type, title, id).
here is my custom sql query ;
SELECT id,
post_title,
post_content,
comment_count,
post_date,
post_status,
post_name
FROM wp_posts
WHERE post_type = 'post'
AND post_status = 'publish'
AND id NOT IN (SELECT DISTINCT post_id
FROM wp_postmeta
WHERE meta_key = 'visible_headlane'
AND meta_value = 'On')
AND id NOT IN (SELECT DISTINCT post_id
FROM wp_postmeta
WHERE meta_key = 'visible_homepage'
AND meta_value = 'On')
ORDER BY post_date DESC
LIMIT 11, 32
i can not use, LIMIT in NOT IN Query so, there is any way to use, or limit SELECT DISTINCT sql query, or any idea ?
Note : I need to optimise this query because, it takes so long , like a slow query.
Thanks.
Switch to NOT EXISTS( SELECT 1 FROM ... ) -- this variation does not need to compute the entire list of things; it only needs to check for the absence. LEFT JOIN .. ON .. IS NULL is also more efficient.
Furthermore, the standard schema for wp_postmeta is quite inefficient; see my suggestions.
Meanwhile, keep it as two tests, unlike the suggestion by 'holder'.
The EXISTS would look something like
AND NOT EXISTS ( SELECT 1 FROM wp_postmeta
WHERE post_id = wp_posts.id
AND meta_key = 'visible_headlane'
AND meta_value = 'On' )
which would make good use of the PRIMARY KEY(post_id, meta_key) that I recommend.
(Is it really 'headlane', not 'headline'?)
Maybe something like this as jarlh suggested
SELECT
ID,post_title,post_content,comment_count,post_date,post_status,post_name
FROM wp_posts t1
left join (
SELECT DISTINCT post_id from wp_postmeta
WHERE meta_key IN ('visible_headlane','visible_homepage') AND meta_value = 'On' ) t2 on t1.ID = t2.post_id
WHERE post_type = 'post'
AND post_status = 'publish'
AND t2.post_id is null
ORDER BY post_date DESC
LIMIT 11, 32
My query gets the results of these products based on if they exist in a separate table index. I am trying to get a count of all the instances where they exist so I can ORDER the results by relevance. Everything I try seems to return the variable #priority as 0. Any ideas?
Maybe it is better to use join statements?
Thank you for your help. Here is my MySQL query:
SELECT `products` . * , #priority
FROM `products`
LEFT JOIN productstypes_index ON productstypes_index.product_id = products.id
WHERE (
EXISTS (
SELECT *
FROM `productstypes_index`
WHERE `productstypes_index`.`product_id` = `products`.`id`
AND `productstypes_index`.`_type_id` = '1'
)
AND (
(
(
EXISTS (
SELECT #priority := COUNT( * )
FROM `producthashtags_index`
WHERE `producthashtags_index`.`product_id` = `products`.`id`
AND `producthashtags_index`.`producthashtag_id` = '43'
)
)
AND (
EXISTS (
SELECT #priority := COUNT( * )
FROM `producthashtags_index`
WHERE `producthashtags_index`.`product_id` = `products`.`id`
AND `producthashtags_index`.`producthashtag_id` = '11'
)
)
)
)
)
ORDER BY `updated_at` DESC;
You could do without those exists, and without variables. Also, a left join has no sense if you have an exists condition on the joined table. Then you might as well do the more efficient inner join and put the extra type condition in the join condition.
The priority can be calculated by a count over the hash tags, but only those with id in ('43', '11').
SELECT products.*
count(distinct producthashtags_index.producthashtag_id) priority
FROM products
INNER JOIN productstypes_index
ON productstypes_index.product_id = products.id
AND productstypes_index._type_id = '1'
INNER JOIN producthashtags_index
ON producthashtags_index.product_id = products.id
AND producthashtags_index.producthashtag_id in ('43', '11')
GROUP BY products.id
ORDER BY updated_at DESC;
MySQL ignores the SELECT list in EXISTS subquery, so it makes no difference what you type in there. This is documented here.
An approach using joins would look like below:
SELECT p.id,
COUNT(case when phi.product_id is not null then 1 end) AS instances
FROM products p
INNER JOIN productstypes_index pti ON pti.product_id = p.id AND pti.`_type_id` = 1
LEFT JOIN producthashtags_index phi ON phi.product_id = p.id AND phi.producthashtag_id IN (11,43)
GROUP BY p.id
ORDER BY instances DESC;
I have removed additional backticks where I believe they are not neccessary and also if your id columns in tables are integers, you do not need quotation marks.
I'm starting in mysql, and I wonder how can I do to remove the result of the SELECT below, thank you all!
SELECT ID,post_name,meta_value, guid, COUNT( meta_value )
FROM wp_postmeta
INNER JOIN wp_posts
WHERE wp_postmeta.post_id = wp_posts.ID AND wp_postmeta.meta_value >100
GROUP BY meta_value
HAVING COUNT( meta_value ) >1
You can first select and create a array or you can directly put this query with delete query using IN clause.
DELETE from wp_posts
WHERE ID IN (
SELECT ID
FROM wp_posts
INNER JOIN wp_postmeta
WHERE wp_postmeta.post_id = wp_posts.ID AND wp_postmeta.meta_value >100
GROUP BY meta_value
HAVING COUNT( meta_value ) >1)
If you set foreign key with postmeta colum post_id as on delete cascade then data from this table will automatically remove.
Otherwise please consider to create unique array of post ids and postmeta ids. And use two separate delete query with IN clause.
What is wrong with my query? Can somebody help me please?
I get this errormessage
"Unknown column 'wp_gdsr_data_article.
(SUM(user_voters)+SUM(visitor_voters))' in 'order clause'"
but the 'wp_gdsr_data_article' colum exist
SELECT *
FROM `wp_posts`
INNER JOIN wp_term_relationships ON wp_term_relationships.object_id = ID AND wp_term_relationships.term_taxonomy_id = 1
INNER JOIN wp_gdsr_data_article ON post_id = ID
WHERE `post_status` = 'publish'
AND `post_type` = 'post'
ORDER BY `wp_gdsr_data_article`.`(SUM(user_voters)+SUM(visitor_voters))` DESC
LIMIT 1 , 30
You are using an expression in the ORDER clause which not a table's column.
Hence you can't use a table identifier on the outcome of an expression.
This is wrong.
ORDER BY `wp_gdsr_data_article`.`(SUM(user_voters)+SUM(visitor_voters))` DESC
Change it to:
ORDER BY (SUM(user_voters)+SUM(visitor_voters)) DESC
And you can't directly use any aggregate function in ORDER BY clause like that.
Calculate SUM... parts separately and then use in ORDER BY.
SELECT * from (
SELECT *, (SUM(user_voters)+SUM(visitor_voters)) total
FROM `wp_posts`
INNER JOIN wp_term_relationships
ON wp_term_relationships.object_id = ID
AND wp_term_relationships.term_taxonomy_id = 1
INNER JOIN wp_gdsr_data_article
ON post_id = ID
WHERE `post_status` = 'publish'
AND `post_type` = 'post'
LIMIT 1 , 30
) results
ORDER BY total
Refer to: How to ORDER BY a SUM() in MySQL?
Remove quotes from all columns and tablenames in your statement. Besides the Order by part should base on a column or an evaluated value in our statement, the way you use it is wrong. you will need to evaluate the part which you use in the order by section before using it for the order by, something like this (untested):
SELECT (SUM(wp_gdsr_data_article.user_voters)+SUM(wp_gdsr_data_article.visitor_voters) as total_voters), *
FROM wp_posts
INNER JOIN wp_term_relationships
ON wp_term_relationships.object_id = ID
AND wp_term_relationships.term_taxonomy_id = 1
INNER JOIN wp_gdsr_data_article
ON post_id = ID
WHERE post_status = 'publish' AND post_type = 'post'
ORDER BY total_voters DESC
LIMIT 1 , 30
Try this
SELECT *, (SUM(wp_gdsr_data_article.user_voters)+SUM(wp_gdsr_data_article.visitor_voters)) AS someSum
FROM `wp_posts`
INNER JOIN wp_term_relationships ON wp_term_relationships.object_id = ID AND wp_term_relationships.term_taxonomy_id = 1
INNER JOIN wp_gdsr_data_article ON post_id = ID
WHERE `post_status` = 'publish'
AND `post_type` = 'post'
ORDER BY someSum DESC
LIMIT 1 , 30