multiple tables for distinct queries in mysql - php

Originally my sql query works to check if there is pending timesheet/overtime ready for manager to review... now i added in on-call timesheets which is on a different table...
my previous sql query that worked but WITHOUT $ONCALL_TABLE...
list($qh, $num) = dbQuery("SELECT manager FROM $USER_TABLE WHERE username IN (SELECT DISTINCT uid FROM $TIMES_TABLE WHERE submitstatus=1 OR ot_status=1)");
now im trying to add the pending on-call timesheet to the same sql query but i keep getting errors... maybe someone can help me fix my syntax?:
list($qh, $num) = dbQuery("SELECT manager FROM $USER_TABLE WHERE username IN (SELECT DISTINCT $TIMES_TABLE.uid, $ONCALL_TABLE.uid FROM $TIMES_TABLE, $ONCALL_TABLE WHERE $TIMES_TABLE.submitstatus=1 OR $TIMES_TABLE.ot_status=1 OR $ONCALL_TABLE.submitstatus=1)");
ERROR I GET:
Can't perform query: Operand should contain 1 column(s)

The problem is in the subquery, but I would handle it using a union all:
SELECT manager
FROM $USER_TABLE
WHERE username IN (SELECT uid
from (select $TIMES_TABLE.uid
from $TIMES_TABLE
where $TIMES_TABLE.submitstatus=1 OR $TIMES_TABLE.ot_status=1
union all
select $ONCALL_TABLE.uid
from $ONCALL_TABLE
where $ONCALL_TABLE.submitstatus=1
) t
)
To be honest, though, the union all may interfere with with the use of indexes. This might perform better:
SELECT manager
FROM $USER_TABLE
WHERE username IN (select $TIMES_TABLE.uid
from $TIMES_TABLE
where $TIMES_TABLE.submitstatus=1 OR $TIMES_TABLE.ot_status=1
) or
username in (select $ONCALL_TABLE.uid
from $ONCALL_TABLE
where $ONCALL_TABLE.submitstatus=1
)

Related

What join to use

I have two tables, one for registered users and one to store votes.
We are logging in with registrants.id and registrants.zipcode. Once they vote their votes are inserted into the votes table, along with their Registration ID.
Im trying to right a select statement that returns a record that will select all the records for Matched ID and Zipcode, but the ID is not in the Votes.voter column. i have tried all kinds of variations of all the joins i can think of. is it something simple i am missing.
SELECT * FROM registrants
LEFT JOIN votes on registrants.id = votes.voter
WHERE registrants.id = 1 AND registrants.zipcode = 46706 and votes.voter <> 1
Perhaps a not exists query:
select * from registrants
where registrants.zipcode = '46706'
and not exists (select 1 from votes where registrants.id = votes.voter)

Complicated INNER JOIN Mysql Query From 3 Tables in Laravel

I've been on this for a few hours without solution. I thought of laravel relationships but don't know how to pass a second condition because I need to relate with 3 tables. I'd like to use the query below in laravel.
SELECT
subscriptions.subscribed_to,
broadcasts. *,
FROM subscriptions
INNER JOIN broadcasts
WHERE subscriptions.subscriber = {$user_id}
AND (
SELECT COUNT(*) FROM seen_broadcasts
WHERE user_id = {$user_id}
AND broadcast_id = broadcasts.id
) = 0
ORDER BY broadcast.date DESC
There are 3 tables.
subscriptions: subscriber_id subscribes to broadcaster_id.
broadcasts: where broadcaster's message is saved.
seen_broadcast: where the information of subscribers are saved when they read a broadcast. This helps us provide detailed stats to broadcaster. user_id = subscriber_user_id, broadcast_id = broadcast_message_id
I want to be able to get broadcasts from all broadcaster that userA has subscribed to and have not seen.
The query above currently works outside laravel.
After much runarounds, I ended up with this:
$broadcast_result = DB::select( DB::raw("
SELECT
subscriptions.subscribed_to,
broadcasts.*
FROM subscriptions
INNER JOIN broadcasts
WHERE subscriptions.browser_agent_id = :subsc_id
AND broadcasts.user_id = subscriptions.subscribed_to
AND (
SELECT COUNT(*) FROM broadcasts_seen
WHERE broadcast_id = broadcasts.id
AND subscriber_id = subscriptions.subscriber_id
) = 0
ORDER BY broadcasts.date DESC LIMIT 1
"), array(
'subsc_id' => $subscriber->id
));
$broadcast_set = $broadcast_result[0];
Also add use DB; in the controller.
If there's a better way to do this, please share.

Picking which data to view in group by

So yesterday, I am trying to sort data in groups made by Group by
I must select which data I want to show in those group
There is list of debts and each person may be in debt in the past but never have more than 1 unpaid debt
I need to know how many times how many times each user have been in debt before this last debt.
This is the column in the data base
Table "Users"
uid | name | date_of_birth
Table "Debt"
uid | debt_duration | paid_count | created_date
I end up with a hack like this in php
$res = mysql_query( "
SELECT * FROM Debt
JOIN Users
WHERE Users.uid = Debt.uid
ORDER BY created_date
GROUP BY Debt.uid");
while( $row = mysql_fetch_array( $res ) ){
$uid = $row['uid'];
$r = mysql_fetch_array( mysql_query("SELECT COUNT(*) FROM Debt WHERE uid = $uid") );
$previous_debts_count = $r[0];
}
This script is quite heavy but fortunately my client doesn't complain.
The script run at around 3 seconds top
But I need to know better ways to do this
sorry for the strange formatting, I am new here ...
I think the query you want is this:
SELECT Users.uid, COUNT(*) as cnt
FROM Debt JOIN
Users
ON Users.uid = Debt.uid
GROUP BY Debt.uid
ORDER BY created_date ;
Just loop through the results and don't use multiple queries for this. Check that Users.uid is the primary key on the users table. And add an index on debt(uid) to improve performance.
First of all, you should never use * in an SQL statement.
It makes the query highly vulnerable to SQL injection.
And I recommend you to use a PDO or a PHP framework.
Try this:
SELECT COUNT(Debt.uid) AS users
FROM Debt
LEFT JOIN Users
ON Users.uid = Debt.uid
GROUP BY Debt.uid

How to write mysql5 query for finding duplicate rows from a table?

Hi I have a table like this
ID UserName
1 test#test.com
2 test#test.com
3 john#stack.com
4 test#test.com
5 adam#stack.com
6 john#stack.com
I need an output like this. I need only repeated rows list. How can I create this kind of an output using mysql query.
ID UserName Count
1 test#test.com 3
2 john#stack.com 2
Please help me.
Thanks.
I had the same problem some time ago and solved it like this (as far as I remember):
SELECT *
FROM tableA INNER JOIN
(SELECT DISTINCT MAX(id) as id, type_id, temp FROM tableA GROUP BY type_id, temp) AS t
ON tableA.id = t.id
AND tableA.type_id = t.type_id
AND tableA.temp = t.temp
You join the table with itself selecting the ids that are duplicate. The fields that should be tested against duplicate values are in this case type_id and temp. If you need more or less fields that should be considered as duplicates you can adjust the fields.
I don't know if this helps in your case and if it can be done in a more simple way, so I'm prepared for downvotes ;-)
Edit: removed last condition AND tableA.id < t.id as suggested by ypercube because it leads to 0 results.
It looks like you're trying to pull the following data:
First ID for a given UserName
The UserName itself
The total number of IDs for that UserName
This query should do the trick:
SELECT
MIN(id),
UserName,
COUNT(id)
FROM users
GROUP BY UserName;
since the ID is not unique so its a bit not logical to get the sum of unique UserName from the table.
If the ID is not required we can get the result from single query.
SELECT UserName, COUNT(UserName) AS Count
FROM TableName GROUP BY UserName
HAVING COUNT(UserName) > 1;
But in the case of ID in the result it will be a more complicated query including sub-query and inner table.
SELECT UserName
, COUNT(*) AS `Count`
FROM tableX
GROUP BY UserName
HAVING COUNT(*) > 1
Hi this is the right answer.
SELECT UserName, COUNT(UserName) AS Count
FROM TableName GROUP BY UserName
HAVING COUNT(UserName) > 1;

unique field from mysql database to php

I have a sample database like this, in which, id is always unique, but the user_id is not unique.
id,user_id,message,msg_datetime
111,u1, msg from u1,time present here
112,u2, msg from u2,time present here
113,u3, msg from u3,time present here
114,u2, msg from u2,time present here
115,u7, msg from u7,time present here
116,u2, msg from u2,time present here
117,u1, msg from u1,time present here
118,u5, msg from u5,time present here
so i want to grab only those unique users who have messaged and order them in DESC by msg_datetime.
This is the query i have.
select id,DISTINCT user_id,msg_datetime ORDER BY msg_datetime DESC but i am getting an error as:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DISTINCT. any help here? what is the correct syntax for what i am trying to achieve?
I want to show only one entry for each user, it does not matter which ID i am showing but only 1 per user.
If you don't care which record with the same user_id query should return, then
SELECT id,user_id,msg_datetime FROM table_1 GROUP BY user_id ORDER BY msg_datetime DESC
If you want to display, for instance, the last record for each user, you need
SELECT a.user_id, a.last_time, b.id
FROM
(SELECT user_id, MAX(msg_datetime) as last_time
FROM table1)a
INNER JOIN table1 b ON (b.user_id = a.user_id AND b.msg_datetime = a.last_time)
ORDER BY a.last_time;
SELECT syntax:
SELECT (fieldlists)
FROM (table)
[WHERE (conditions)]
ORDER BY (something)
You kindof forgot to say which table you want the data from.
You misunderstand how DISTINCT works. It works on rows not fields. What you want is a groupwise maximum, also known as greatest-n-per-group.
Here's one way to do it in MySQL:
SELECT id, user_id, message, msg_datetime
FROM (
SELECT
id, user_id, message, msg_datetime,
#rn := CASE WHEN #prev_user_id = user_id
THEN #rn + 1
ELSE 1
END AS rn,
#prev_user_id := user_id
FROM (SELECT #prev_user_id := NULL) vars, Table1 T1
ORDER BY user_id, msg_datetime DESC
) T2
WHERE rn = 1
ORDER BY msg_datetime

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