There are a lot of questions posted on stackoverflow that are almost same like my problem but I found no working solution. I have a table message and entries are:
id | Message | Status
1 | Hello | 1
2 | Hiiii | 0
4 | Works | 1
I have another table which gives ids 1,2,3 and I want to find the status of all these entries from message table. What I want is if an id doesn't exist in message table then it should return null for that id if I use IN clause to find all status. I want following result:
id | Status
1 | 1
2 | 0
3 | null
I have been using IN clause but didn't get working output. Then I got a solution on stackoverflow and tried this query
SELECT `id`,`status` FROM ( SELECT 1 AS ID UNION ALL SELECT 2 AS ID UNION ALL SELECT 3) ids LEFT OUTER JOIN message ON ids.ID = message.id
But this query is not giving the expected results. Any help would be much appreciated.
I don't see how your query would work. The column id should be ambiguous in the select (unless your database is case sensitive). Try this:
SELECT ids.ID, m.status
FROM ( SELECT 1 AS ID UNION ALL SELECT 2 AS ID UNION ALL SELECT 3
) ids LEFT OUTER JOIN
message m
ON ids.ID = m.id;
Related
situation:
table 1 - #__virtuemart_products
virtuemart_product_id | product_special
PRODUCTS_IDS | 0 or 1
table 2 - #__virtuemart_product_badges
virtuemart_product_id | product_badge
PRODUCTS_IDS | for this situation code 3
I have a default SQL
SELECT p.`virtuemart_product_id`
FROM `#__virtuemart_products` as p
WHERE p.`product_special` = 1;
results is product IDs like 2,3,225,...
I need modify this SQL syntax for select IDs from 2 different tables and return one column.
If I modify syntax like that:
SELECT p.`virtuemart_product_id`, badges_table.`virtuemart_product_id`
FROM `#__virtuemart_products` as p, `#__virtuemart_product_badges` as badges_table
WHERE p.`product_special` = 1 OR badges_table.`badge` = 3
Result is:
virtuemart_product_id | virtuemart_product_id
1 | 123
1 | 321
1 | 231
....
why is first column 1,1,1,...? here must be product_id, no product_special code
I need group this results into one column virtuemart_product_id
What I doing wrong?
I think what you are looking for is UNION of the IDs fetched from two different tables.
SELECT p.`virtuemart_product_id`, badges_table.`virtuemart_product_id`
FROM `#__virtuemart_products` as p, `#__virtuemart_product_badges` as
badges_table
WHERE p.`product_special` = 1 OR badges_table.`badge` = 3
What the above query is doing is, it is performing a join between the two tables with the condition that product_special should be 1 or badge should be 3. Hence, each row from one table will be joined with each row of the other table where the condition will satisfy.
To get IDs from both the tables you can get the results from each table according to condition and then perform a UNION on them. So for example
(SELECT `virtuemart_product_id` FROM `#__virtuemart_products` WHERE
`product_special` = 1)
UNION
(SELECT `virtuemart_product_id` FROM
`#__virtuemart_product_badges` WHERE `badge` = 3)
I hope this helps.
Not sure if this is possible but I have a schema like this:
id | user_id | thread_id
1 | 1 | 1
2 | 4 | 1
3 | 1 | 2
4 | 3 | 2
I am trying to retrieve the thread_id where user_id = 1 and 4. I know that in(1,4) does not fit my needs as its pretty much a OR and will pull up record 3 as well and Exists only returns a bool.
You may use JOIN (that answer already exists) or HAVING, like this:
SELECT
thread_id,
COUNT(1) AS user_count
FROM
t
WHERE
user_id IN (1,4)
GROUP BY
thread_id
HAVING
user_count=2
-check the demo. HAVING will fit better in case of many id's (because with JOIN you'll need to join as many times as many id you have). This is a bit tricky, however: you may do = comparison only if your records are unique per (user_id, thread_id); for example, your user_id can repeat, then use >=, like in this demo.
Try this with join, i guess you need to do AND operation with user_id must be 4 and 1 then
SELECT
t1.thread_id
FROM
TABLE t1
JOIN TABLE t2
ON (t1.user_id = t2.user_id)
WHERE t1.user_id = 1
AND t2.user_id = 4
There are a number of left join questions already, but still I can't quite put my finger on this issue. The WHERE condition doesn't look sensible to move.
The problem is that there should be 4 rows returned but only 1 is.
In checking the left join conditions, there is 1 row returned for each left join, which is correct for the number of records in the table, however the query below returns 1 record instead of 4, but I can't see how to return 4, yet.
Query follows: (Gives 1 result not 4; 4 being expected)
SELECT
list.uid,
list.business_uid,
list.creator_name,
business.company_name,
list_alias.uid AS list_alias_uid,
list_alias.alias AS list_alias,
list_member.uid AS list_member_uid,
mailbox.full_name AS list_member_name,
mailbox.email_address AS list_member_email_address
FROM
mailbox,
business,
list
LEFT JOIN
list_alias ON list_alias.list_uid=list.uid
LEFT JOIN
list_member ON list_member.list_uid=list.uid
WHERE
list.business_uid='1'
AND list.business_uid=business.uid
AND mailbox.uid=list_member.mailbox_uid
ORDER BY
list.full_name ASC
Data:
Business UID 1 has 4 lists
SELECT * FROM list WHERE business_uid=1 -- gives 4 results
SELECT * FROM list_alias WHERE list_uid IN (SELECT uid FROM list WHERE business_uid=1) -- gives 1 result
SELECT * FROM list_member WHERE list_uid IN (SELECT uid FROM list WHERE business_uid=1) -- gives 1 result
Any pointers on what I could check would be welcome.
Table Sample Data:
list:
uid | business_uid | creator_name | full_name
--------------------------------------------------
1 1 List Maker Subscribe to W
2 1 List Maker Subscribe to X
3 1 List Maker Subscribe to Y
4 1 List Maker Subscribe to Z
business:
uid | company_name
-------------------
1 List Company
list_alias:
uid | list_uid | alias
----------------------------------------
1 1 subscriber#list-url.com
list_member:
uid | list_uid | mailbox_uid
------------------------------------
1 1 1
mailbox:
uid | full_name | email_address
-------------------------------
1 I am He me#me.com
Try this using a single join methodology, like so.
SELECT list.uid,
list.business_uid,
list.creator_name,
b.company_name,
la.uid AS list_alias_uid,
la.alias AS list_alias,
lm.uid AS list_member_uid,
m.full_name AS list_member_name,
m.email_address AS list_member_email_address
FROM list LEFT JOIN list_member lm ON lm.list_uid=list.uid
LEFT JOIN mailbox m ON m.uid=lm.mailbox_uid
LEFT JOIN business b ON list.business_uid=b.uid
LEFT JOIN list_alias la ON la.list_uid=list.uid
WHERE list.business_uid=1
ORDER BY list.full_name ASC
Question: What are the values of 'uid' from the 'list' table? Because 'uid' is not the same as 'business_uid'. What I mean is ...
If the 'list' table has this ...
'uid' 'business_uid'
1 1
2 1
3 1
4 1
Then that is the problem. You are returning the same 'busines_uid' but a different 'uid' which means it will only match the first record.
I need to count the number of duplicate emails in a mysql database, but without counting the first one (considered the original). In this table, the query result should be the single value "3" (2 duplicate x#q.com plus 1 duplicate f#q.com).
TABLE
ID | Name | Email
1 | Mike | x#q.com
2 | Peter | p#q.com
3 | Mike | x#q.com
4 | Mike | x#q.com
5 | Frank | f#q.com
6 | Jim | f#q.com
My current query produces not one number, but multiple rows, one per email address regardless of how many duplicates of this email are in the table:
SELECT value, count(lds1.leadid) FROM leads_form_element lds1 LEFT JOIN leads lds2 ON lds1.leadID = lds2.leadID
WHERE lds2.typesID = "31" AND lds1.formElementID = '97'
GROUP BY lds1.value HAVING ( COUNT(lds1.value) > 1 )
It's not one query so I'm not sure if it would work in your case, but you could do one query to select the total number of rows, a second query to select distinct email addresses, and subtract the two. This would give you the total number of duplicates...
select count(*) from someTable;
select count(distinct Email) from someTable;
In fact, I don't know if this will work, but you could try doing it all in one query:
select (count(*)-(count(distinct Email))) from someTable
Like I said, untested, but let me know if it works for you.
Try doing a group by in a sub query and then summing up. Something like:
select sum(tot)
from
(
select email, count(1)-1 as tot
from table
group by email
having count(1) > 1
)
I have a table of services that have been provided to clients. I'm trying to make a query that selects all the clients who received a service that WEREN'T provided by a certain user.
So consider this table...
id_client | id_service | id_user
--------------------------------
5 | 3 | 2
7 | 4 | 2
7 | 4 | 1
9 | 4 | 2
8 | 4 | 1
If I write the query like this:
SELECT id_client FROM table WHERE id_service=4 AND id_user<>1
I still end up getting id_client 7. But I don't want to get client 7 because that client HAS received that service from user 1. (They're showing up because they've also received that service from user 2)
In the example above I would only want to be returned with client 9
How can I write the query to make sure that clients that have EVER received service 4 from user 1 don't show up?
Try this:
SELECT DISTINCT id_client
FROM yourtable t
WHERE id_service = 4 AND id_client NOT IN
(SELECT DISTINCT id_client
FROM yourtable t
WHERE id_user = 1
)
I'd write it like this:
SELECT DISTINCT id_client
FROM mytable t1
LEFT OUTER JOIN mytable t2
ON t1.id_client = t2.id_client AND t2.id_user = 1
WHERE t2.id_client IS NULL
When the conditions of a left outer join are not met, the row on the left side is still returned, and all the columns for the row on the right side are null. So if you search for cases of null in a column that would be certain to be non-null if there were a match, you know the outer join found no match.
SELECT id_client
FROM table
WHERE id_service = 4
GROUP BY id_client
HAVING MAX(CASE
WHEN id_user = 1 THEN 2
ELSE 1
END) = 1