I've got query.
SELECT * FROM '.PRFX.'sell
WHERE draft = "0" '.$e_sql.'
AND ID NOT IN (SELECT id_ FROM '.PRFX.'skipped WHERE uid = "'.$u.'")
AND ID NOT IN (SELECT id_ FROM '.PRFX.'followed WHERE uid = "'.$u.'")
ORDER BY raised DESC '.$sql_limit;
I want to add 3 records by the lowest number of refreshes; best on 5th position
they must be unique (so if you connect two UNION ALL...)
Firstly, you need make your SQL more readable. Something like this
SELECT * FROM sell
WHERE draft = 0
AND ID NOT IN (SELECT id_ FROM skipped WHERE uid = '0')
AND ID NOT IN (SELECT id_ FROM followed WHERE uid = '0')
ORDER BY raised DESC LIMIT 15
Then, what do you want? Add data to sell table through single request? This can be done with such request
INSERT INTO sell (key1, key2, keyN)
VALUES
('aaa', 'bbb', 'ccc'),
('ddd', 'eee', 'fff');
-- and so forth.
Related
When a post is accessed, I need, in addition to returning the information of this posts, to return the previous one if it exists and the next one.
I would like to know if there is a way to select MAX(id) and MIN(id) in a single query/select, passing a condition for each one of them. Example of what I'm trying to do in Laravel and I'll write it in SQL to make it easier too
Laravel:
$query = Post::query();
$query = $query->from('posts')->select(DB::raw('MAX(id), MIN(id)'))->whereRaw("id < {$id} and id > {$id}")->first();
SQL:
select MAX(id), MIN(id) from `posts` where id < 5 and id > 5 limit 1
The id variable is the post id value. In this example, it has the value 5. The query I'm doing is to get the MAX and MIN referring to this id, but I also need to get the info of the post that the user accessed.
The DB has post id number 4 and number 6. That is, I need to get the information from posts number 4, 5 and 6 in this example.
The where condition will never be true, but I cannot use or. The first condition is for MAX and the second for MIN. If I use the or, the biggest id will come of the DB.
I need to get the min and max value compared to a value. That is, as I explained above. If the id is 5, I need to get the largest existing id() below that value and I need to get the smallest value above it. In my case, from the information I have in the DB, it would be id 4, 5 and 6
Is it possible in a single consultation or do I really have to do more than one?
Yes, you can do it with case-when
select MAX(
CASE
WHEN id < 5 THEN id
ELSE NULL
END
), MIN(
CASE
WHEN id > 5 THEN id
ELSE NULL
END
)
from `posts`
where id <> 5
EDIT
Laravel equivalent, as shared by Gabriel Edu in the comment-section:
$query = Post::query();
$query = $query->from('posts')->
select(DB::raw("MAX(CASE WHEN id < {$id} THEN id ELSE null END), MIN(CASE WHEN id > {$id} THEN id ELSE null END)"))->first();
The LEAD() and LAG() function in MySQL are used to get preceding and succeeding value of any row within its partition.
Try this:
SELECT ID,
LAG (id) OVER (ORDER BY NULL) ONE_SHIFT_FORWARD,
LEAD (id) OVER (ORDER BY NULL) ONE_SHIFT_BACKWARD
FROM POSTS
ORDER BY ID ASC;
SELECT *
FROM ( SELECT ID,
LAG (id) OVER (ORDER BY NULL) ONE_SHIFT_FORWARD,
LEAD (id) OVER (ORDER BY NULL) ONE_SHIFT_BACKWARD
FROM POSTS
ORDER BY ID ASC)
WHERE id = 5;
You may use lead and lag to access the values before and after the current row.
You may then use those to select the post with a given id and the values before and after in a single select.
The following query
select *
from (
select
p.*,
lead(id) over(order by id) _lead,
lag(id) over(order by id) _lag
from post p
) x
where 23 in (id, _lead, _lag);
results in
id
text
_lead
_lag
15
fifteen
23
10
23
twentythree
24
15
24
twentyfour
50
23
With the following setup:
Schema (MySQL v8.0)
create table post (
id integer,
text varchar(50)
);
insert into post(id, text)
values
( 10, 'ten'),
( 15, 'fifteen'),
( 23, 'twentythree'),
( 24, 'twentyfour'),
( 50, 'fifty');
View on DB Fiddle
I am using a MySQL query to fetch data from 2 tables. Here I have a status Transfer Out in table2. I do need to fetch all the details with status Transfer Out and at the same time, there should not be any details with Transfer In status which is added after the Transfer Out. So that I should not get the details which are Transfer back In after a Transfer Out.
Right now I am using subquery for the same. But when the data count gets higher, it is causing timeout issues. Is there a better way to rewrite the query and get the same result?
My query sample is
SELECT sq.etid
FROM (
SELECT og.etid, pt.timestamp
FROM og_membership og
INNER JOIN table1 n ON(n.nid=og.etid)
INNER JOIN table2 pt ON(og.etid=pt.animal_nid)
WHERE og.entity_type='node'
AND pt.partner_gid = :gid
AND pt.shelter_gid = :our_gid
AND pt.type = 'Transfer Out'
AND (
SELECT count(id)
FROM table2
WHERE timestamp > pt.timestamp
AND type = 'Transfer In'
AND partner_gid = :gid
AND shelter_gid = :our_gid
) = 0
) AS sq
You could possibly do this with a group by for example
select something
from somehwere
group by something having isnull(max(out_date),0) > isnull(max(indate) ,0)
For example
DROP TABLE IF EXISTS LOANS;
CREATE TABLE LOANS (ID INT AUTO_INCREMENT PRIMARY KEY, ISBN INT,DIRECTION VARCHAR(3), DT DATETIME);
INSERT INTO LOANS(ISBN,DIRECTION,DT) VALUES
(1,'OUT','2017-10-01 09:00:00'),
(2,'OUT','2017-10-02 10:00:00'),
(2,'IN', '2017-10-02 10:10:00'),
(3,'REC','2017-10-02 10:00:00'),
(4,'REC','2017-10-02 10:00:00'),
(4,'OUT','2017-10-03 10:00:00'),
(4,'IN', '2017-10-04 10:00:00'),
(4,'OUT','2017-10-05 10:00:00')
;
SELECT ISBN
FROM LOANS
WHERE DIRECTION IN('OUT','IN')
GROUP BY ISBN HAVING
MAX(CASE WHEN DIRECTION = 'OUT' THEN DT ELSE 0 END) >
MAX(CASE WHEN DIRECTION = 'IN' THEN DT ELSE 0 END) ;
result
+------+
| ISBN |
+------+
| 1 |
| 4 |
+------+
2 rows in set (0.00 sec)
In case of a tie on DT you could substitute id.
Change
( SELECT COUNT(id) FROM ... ) = 0
to
EXISTS ( SELECT 1 FROM ... )
Get rid of the outermost query and the first pt.timestamp. (Or is there some obscure reason for pt.timestamp?)
table2 needs INDEX(type, partner_gid, shelter_gid, timestamp). timestamp must be last, but the others can be in any order.
table2 needs INDEX(type, partner_gid, shelter_gid, animal_nid); the columns can be in any order. (This index cannot be combined with the previous one.)
og_membership needs INDEX(etid, entity_type) (in either order).
Why do you have INNER JOIN table1 n ON(n.nid=og.etid) in the query? table1 does not seem to be used at all -- except maybe for verifying the existence of a row. Remove it if possible.
After making changes, please provide EXPLAIN SELECT ... and SHOW CREATE TABLE for the 2 (or 3??) tables.
let's say I have the following Table:
ID, Name
1, John
2, Jim
3, Steve
4, Tom
I run the following query
SELECT Id FROM Table WHERE NAME IN ('John', 'Jim', 'Bill');
I want to get something like:
ID
1
2
NULL or 0
Is it possible?
How about this?
SELECT Id FROM Table WHERE NAME IN ('John', 'Jim', 'Bill')
UNION
SELECT null;
Start by creating a subquery of names you're looking for, then left join the subquery to your table:
SELECT myTable.ID
FROM (
SELECT 'John' AS Name
UNION SELECT 'Jim'
UNION SELECT 'Bill'
) NameList
LEFT JOIN myTable ON NameList.Name = myTable.Name
This will return null for each name that isn't found. To return a zero instead, just start the query with SELECT COALESCE(myTable.ID, 0) instead of SELECT myTable.ID.
There's a SQL Fiddle here.
The question is a bit confusing. "IN" is a valid operator in SQL and it means a match with any of the values (see here ):
SELECT Id FROM Table WHERE NAME IN ('John', 'Jim', 'Bill');
Is the same as:
SELECT Id FROM Table WHERE NAME = 'John' OR NAME = 'Jim' OR NAME = 'Bill';
In your answer you seem to want the replies for each of the values, in order. This is accomplished by joining the results with UNION ALL (only UNION eliminates duplicates and can change the order):
SELECT max(Id) FROM Table WHERE NAME = 'John' UNION ALL
SELECT max(Id) FROM Table WHERE NAME = 'Jim' UNION ALL
SELECT max(Id) FROM Table WHERE NAME = 'Bill';
The above will return 1 Id (the max) if there are matches and NULL if there are none (e.g. for Bill). Note that in general you can have more than one row matching some of the names in your list, I used "max" to select one, you may be better of in keeping the loop on the values outside the query or in using the (ID, Name) table in a join with other tables in your database, instead of making the list of ID and then using it.
I would like to select multiple values from a single column in a database table that equal to a number of values. I want all these values to match otherwise it should return no rows. I do not want to use "IN" as that is equal to "OR".
The following is a basic mockup of what it should do but it needs to be dynamic as I wish to use it with a PDO statement. If the database only contains id's 1 and 2 it should fail ie return no rows.
SELECT
id
FROM
reports
WHERE
id=1 AND id=2 AND id=3
I have the current code as follow which is incorrectly returning zero rows:
SELECT id,title
FROM reports
WHERE id IN (1,2)
GROUP BY title
HAVING COUNT(DISTINCT id) = 2
My current table structure is as follows:
http://www.sqlfiddle.com/#!2/ce4aa/1
You have to use HAVING COUNT(id) = 3 to ensure that the selected rows have all the three id's. Something like:
SELECT *
FROM reports
WHERE id = 1 OR id = 2 OR id = 3 -- Or id IN(1, 2, 3)
GROUP BY SomeOtherField
HAVING COUNT(DISTINCT id) = 3;
Or:
SELECT *
FROM reports
WHERE SomeOtherField IN (SELECT SomeOtherField
FROM reports
WHERE id = 1 or id = 2 -- Or id IN(1, 2, 3)
GROUP BY SomeOtherField
HAVING COUNT(DISTINCT id) = 3
);
Note that: You have to GROUP BY SomeOtherField where SomeOtherField is other field than id because if you GROUP BY id with HAVING COUNT(id) you won't get any records, since COUNT(id) will be always = 1.
Edit: fixed WHERE clause, OR's instead of AND's.
SQL Fiddle Demo
just a quick question:
i have to have one single query that has multiple rows - some rows are identicle - and the order of rows must be preserved in the result -
some idea of what im refering to:
SELECT id,date
FROM items
WHERE id IN (1,2,1,3)
ORDER BY id=1 DESC,id=2 DESC,id=1 DESC,id=3 DESC;
unfortunately mysql result is this:
1,2,3
not 1,2,1,3
it removes the duplicate which i have to have in my result to display in multiple panels on the same webpage -
i really dont want to loop thru each id one by one to get them the way i want to display -
is there a way to actually have one single query that will preserve the order and pull out rows based on request whether its unique or not -
Your query as it stands will never work, because duplicate values in a list of values of an IN clause are ignored. The only way to make this work is by using UNION ALL:
SELECT id, date FROM items where id = 1
UNION ALL
SELECT id, date FROM items where id = 2
UNION ALL
SELECT id, date FROM items where id = 1
UNION ALL
SELECT id, date FROM items where id = 3;
But to be frank, I suspect your data model so far past screwed it's unusable.
try
SELECT
id,
date
FROM items
WHERE id IN (1,2,1,3)
ORDER BY FIND_IN_SET(id, '1,2,1,3')
Another scrupulous way to answer a suspicious question:
SELECT
items.id,
items.date
FROM
items
JOIN
( SELECT 1 AS id, 1 AS ordering
UNION ALL
SELECT 2, 2
UNION ALL
SELECT 1, 3
UNION ALL
SELECT 3, 4
) AS auxilary
ON
auxilary.id = items.id
ORDER BY
auxilary.ordering
Another approach (untested, but should give you the idea):
CREATE TEMPORARY TABLE tt (id INT, ai int unsigned auto_increment primary key);
INSERT INTO tt (id) VALUES (1), (2), (1), (3);
SELECT
id,
date
FROM items JOIN tt USING (id)
ORDER BY tt.ai;
keeps the given order.
If you want to include the records with id=1 and the order doesn't matter as long as you get them, you can split your query into two queries, one for (1,2,3) union all the other query for id=1 or just do:
... In (1,2)
Union all
... In (1,3)
Example:
Select * from
(Select case id when 1 then 1 when 2 then 2 as pseudocol, othercolumns
From table where Id in (1,2)
Union all
Select case id when 1 then 3 when 3 then 4 as pseudocol, othercolumns
From table where Id in (1,3)) t order by pseudocol
Instead of doing what you are trying to, just select the unique rows you need. In the frontend code, store each unique row once in a key=>value structure, where key is the item ID and value is whatever data you need about that item.
Once you have that you can use frontend logic to output them in the desired order including duplicates. This will reduce the amount of redundant data you are trying to select.
For example This is not usable code - exact syntax required depends on your scripting language
-- setup a display order
displayOrder= [1,2,1,3];
-- select data from database, order doesn't matter here
SELECT id,date
FROM items
WHERE id IN (displayOrder);
-- cache the results in a key=> value array
arrCachedRows = {};
for (.... each db row returned ...) {
arrCachedRows[id] = date;
}
-- Now output in desired order
for (listIndex in displayOrder) {
-- Make sure the index is cached
if (listIndex exists in arrCachedRow) {
echo arrCachedRows[listIndex ];
}
}
If you must persist in using UNION despite my warnings
If you go against the above recommendation and absolutely MUST have them back in 1 query in that order then add on an additional row which will enforce the row order. See below query where I use variable #subIndex to add an incrementing value as subIndex. This in turn lets you reorder by that and it'll be in the requested order.
SELECT
i.*
FROM (
SELECT #subIndex:=#subIndex+1 AS subIndex, id, date FROM items where id = 1
UNION
SELECT #subIndex:=#subIndex+1 AS subIndex, id, date FROM items where id = 2
UNION
SELECT #subIndex:=#subIndex+1 AS subIndex, id, date FROM items where id = 1
UNION
SELECT #subIndex:=#subIndex+1 AS subIndex, id, date FROM items where id = 3
) AS i,(SELECT #subIndex:=0) v
ORDER BY i.subIndex
Or a slightly cleaner version that keeps item selection until the outside and hides the subindex
SELECT
items.*
FROM items
-- initialise variable
INNER JOIN (SELECT #subIndex:=0) v
-- create a meta-table with the ids desired in the order desired
INNER JOIN (
SELECT #subIndex:=#subIndex+1 AS subIndex, 1 AS id
UNION
SELECT #subIndex:=#subIndex+1 AS subIndex, 2 AS id
UNION
SELECT #subIndex:=#subIndex+1 AS subIndex, 1 AS id
UNION
SELECT #subIndex:=#subIndex+1 AS subIndex, 3 AS id
) AS i
ON i.id = items.id
-- order by the subindex from i
ORDER BY i.`subIndex` ASC