Hope you can help me with correct syntax of a SQL query (using MySQL 5.5.25).
I have 3 tables:
data
data_tmp
users
data table is empty - has it's own structure but no rows
data:
id | name | who
----------------
data_tmp:
id | cars | who
---------------
1 | lambo| 2
users
who | name |
------------
2 | john
My query is:
SELECT DISTINCT
users.name,
(SELECT count(id) FROM data WHERE who = 1) as number,
data_tmp.cars
FROM
users, data, data_tmp
WHERE
users.who = 2
AND data_tmp.who = 2
AND data.who = 2
This of course returns an empty result (there is no row that suits to all parameters because data is empty).
What I would like to achieve is:
users.name | number | data_tmp.cars |
-------------------------------------
john | 0 | lambo |
I am sure I have to - in some way - use LEFT JOIN but can't find correct syntax. Hope you can help me.
Kalreg
give this a try (without using subquery)
SELECT a.name, b.cars, count(c.id) as number
FROM users a
INNER JOIN data_tmp b
on a.who = b.who
LEFT JOIN data c
on a.who = c.who AND
a.name = c.name
WHERE a.who = 2
GROUP BY a.name, b.cars
this works on different servers:
MSSQL SERVER # SQLFIDDLE
MYSQL # SQLFIDDLE
Your assumption is right: you have to use left JOIN, in this way :
SELECT DISTINCT users.name, (SELECT count(id) FROM data WHERE who = 1) as number, data_tmp.cars
FROM users
JOIN data_tmp USING (who)
LEFT JOIN data USING(who)
WHERE users.who = 2
Related
For transaction listing I need to provide the following columns:
log_out.timestamp
items.description
log_out.qty
category.name
storage.name
log_out.dnr ( Representing the users id )
Table structure from log_out looks like this:
| id | timestamp | storageid | itemid | qty | categoryid | dnr |
| | | | | | | |
| 1 | ........ | 2 | 23 | 3 | 999 | 123 |
As one could guess, I only store the corresponding ID's from other tables in this table. Note: log_out.id is the primary key in this table.
To get the the corresponding strings, int's or whatever back, I tried two queries.
Approach 1
SELECT i.description, c.name, s.name as sname, l.*
FROM items i, categories c, storages s, log_out l
WHERE l.itemid = i.id AND l.storageid = s.id AND l.categoryid = c.id
ORDER BY l.id DESC
Approach 2
SELECT log_out.id, items.description, storages.name, categories.name AS cat, timestamp, dnr, qty
FROM log_out
INNER JOIN items ON log_out.itemid = items.id
INNER JOIN storages ON log_out.storageid = storages.id
INNER JOIN categories ON log_out.categoryid = categories.id
ORDER BY log_out.id DESC
They both work fine on my developing machine, which has approx 99 dummy transactions stored in log_out. The DB on the main server got something like 1100+ tx stored in the table. And that's where trouble begins. No matter which of these two approaches I run on the main machine, it always returns 0 rows w/o any error *sigh*.
First I thought, it's because the main machine uses MariaDB instead of MySQL. But after I imported the remote's log_out table to my dev-machine, it does the same as the main machine -> return 0 rows w/o error.
You guys got any idea what's going on ?
If the table has the data then it probably has something to do with JOIN and related records in corresponding tables. I would start with log_out table and incrementally add the other tables in the JOIN, e.g.:
SELECT *
FROM log_out;
SELECT *
FROM log_out
INNER JOIN items ON log_out.itemid = items.id;
SELECT *
FROM log_out
INNER JOIN items ON log_out.itemid = items.id
INNER JOIN storages ON log_out.storageid = storages.id;
SELECT *
FROM log_out
INNER JOIN items ON log_out.itemid = items.id
INNER JOIN storages ON log_out.storageid = storages.id
INNER JOIN categories ON log_out.categoryid = categories.id;
I would execute all the queries one by one and see which one results in 0 records. Additional join in that query would be the one with data discrepancy.
You're queries look fine to me, which makes me think that it is probably something unexpected with the data. Most likely the ids in your joins are not maintained right (do all of them have a foreign key constraint?). I would dig around the data, like SELECT COUNT(*) FROM items WHERE id IN (SELECT itemid FROM log_out), etc, and seeing if the returns make sense. Sorry I can't offer more advise, but I would be interested in hearing if the problem is in the data itself.
I've looked at a bunch of questions and solutions regarding many to many queries. I just can't seem to wrap my head around it. Maybe I'm not completely understanding the keywords in MySQL. But...
I have 3 tables. The first table is a list of peoples contact information. The second table is a list of mailing list categories. The third table is an associative table that holds the id's from the first and second table. How would I write a MySQL query to get all the contacts from the contact table that match the VIP list id (which I already have)?
Table 1 (contacts)
id | name | email
-----------------------------
1 | John | john#gmail.com
-----------------------------
2 | Jane | jane#gmail.com
-----------------------------
Table 2 (list_type)
id | list_name |
-----------------
1 | VIP's |
-----------------
2 | Generic |
-----------------
Table 3 (list_contact_joiner)
contact_id | list_type_id |
----------------------------
1 | 2 |
----------------------------
2 | 1 |
----------------------------
This is what I tried but get a syntax error
$listID = 1;
SELECT list_contact_joiner.contact_id
FROM list_contact_joiner
WHERE list_id = $listID AS lcj
INNER JOIN contact_lists AS cl
ON cl.id = lcj.contact_id
SELECT c.*
FROM contacts c
JOIN list_contact_joiner j on j.contact_id = c.id
JOIN list_type t on j.list_type_id = t.id
WHERE t.list_name = 'VIP''s'
If you already have the id of VIP's then you need to join only 2 tables
SELECT c.*
FROM contacts c
JOIN list_contact_joiner j on j.contact_id = c.id
WHERE j.list_type_id = 1
Yes the join statement is not correct. It should be something as
select
c.name,
c.email,
lt.list_type
from list_contact_joiner lcj
join contacts c on c.id = lcj.contact_id
join list_type lt on lt.id = lcj.list_type_id
where
lt.id = ?
If you are looking for data with $listID = 1; then the place holder is
lt.id = ?
Your syntax error is because all the table specification (FROM and JOIN) has to occur before the WHERE and you got your alias syntax a little messed up - this should work better:
$listID = 1;
SELECT lcj.contact_id
FROM list_contact_joiner AS lcj
INNER JOIN contact_lists AS cl
ON cl.id = lcj.contact_id
WHERE lcj.list_id = $listID
But if all you are trying to do is get the contact_id then you don't need to do any join at all...
SELECT contact_id
FROM list_contact_joiner
WHERE list_id = $listID
If you need the rest of the contact information then you might try this:
SELECT contact.*
FROM list_contact_joiner
JOIN contacts ON contacts.id = list_contact_joiner.contact_id
WHERE list_id = $listID
Note that you still don't need to get the list_type table at all.
I've got two tables, that are not linked the standard way (I'm aware this isn't a good way to do it)
lets say the tables are setup like the below
Table:
component
fields:
cid, cname, rangeid, company
Table: ranges
fields:
rid, rangename, year
While this is quite simple in a relational DB, i'm not too sure of the cleanest way to do this otherwise (remaking the DB is not an option).
the basic query I need is.
select * from component where range.year = '2014' and company = 'xxx'
any advice would be greatly appreciated.
Is this what you're looking for?
SELECT a.cid, a.cname, a.rangeid, a.company, b.rid, b.rangename, b.year
FROM component a
JOIN ranges b ON
b.rid = a.rangeid
WHERE b.year = 2014
AND a.company = 'xxx'
Result
| CID | CNAME | RANGEID | COMPANY | RID | RANGENAME | YEAR |
------|-----------|---------|---------|-----|-----------|------|
| 1 | Component | 1 | xxx | 1 | Range | 2014 |
Demo
If a range from component may not exist in ranges, then use a LEFT JOIN.
JOIN the two tables:
select c.cname, r.rangename, r.year, ...
from component AS c
INNER JOIN ranges AS r ON c.rangeid = r.rid
where r.year = '2014'
and c.company = 'xxx';
Note that: You can JOIN any tables normally, even if they haven't any relation between them, just put the condition in the ON clause, just like in your case. But, you have to ensure that indexes are setup correctly, see this page fore more information:
Multiple-Column Indexes
JOIN is what you are looking for :
select *
from component
inner join ranges on rid = rangeid and year = 2014
where company = 'xxx'
Maybe a bit of a strange title description, but i basically want to achieve something the GROUP_CONCAT() function does, only then keep the double entries.
I have four tables i want to join, client, doctor, physio and records
Depending on the variable $client i want to get the client details, attending doctor and therapist (one single row from three tables) and join all records for that user.
Say that in this case the $client = 1. The records table has five records where the column r_client_id = 1. If i run a query like below i only get one record from the records table, namely the first occurrence where r_client_id = 1 (which makes sense of course):
SELECT
client.c_id, client.c_name
doctor.d_name,
physio.p_name,
records.r_record
FROM
adm_clients AS client
INNER JOIN
norm_client_doctor AS ncd ON ncd.ncd_client_id = client.c_id
INNER JOIN
adm_doctor AS doctor ON doctor.d_id = ncd.ncd_doctor_id
INNER JOIN
norm_client_physio AS ncp ON ncp.ncp_client_id = client.c_id
INNER JOIN
adm_physio AS physio ON physio.p_id = ncp.ncp_physio_id
LEFT JOIN
adm_doctor_records AS records ON records.r_client_id = client.c_id
WHERE
client.c_id = '".$client."'
Now assume the five records where r_client_id = 1 are like so:
+------+-------------+-------------------+----------+
| r_id | r_client_id | r_record | r_date |
+------+-------------+-------------------+----------+
| 1 | 1 | regular visit | 10/10/12 |
+------+-------------+-------------------+----------+
| 3 | 1 | emergency control | 24/10/12 |
+------+-------------+-------------------+----------+
| 7 | 1 | regular visit | 08/09/12 |
+------+-------------+-------------------+----------+
| 18 | 1 | delivery | 03/01/12 |
+------+-------------+-------------------+----------+
| 20 | 1 | health checkup | 10/12/11 |
+------+-------------+-------------------+----------+
I want my output to be in an array like so:
Client 1
- Name Doctor
- Name Physio
Records
- Emergency control, 24/10/12
- Regular visit, 10/10/12
- Regular visit, 08/09/12
- Delivery, 03/01/12
- Health checkup, 10/12/11
The closest one i can image is a to add a GROUP_CONCAT() on the records, but that, of course, groups the 'regular visit', so i'll get 4 rows instead of 5
GROUP_CONCAT(DISTINCT records.r_record SEPARATOR '|')
[..]
echo(str_replace("|","<br>",$show->r_record));
Anybody an idea how to display all the matching records? I have the feeling i'm close, but i'm out of options by now..
Edit:
I forgot to mention that when i remove the DISTINCT, it displays all the records twice..
SOLVED:
Got it working like so:
GROUP_CONCAT(DISTINCT
CONCAT (records.r_date, '~', records.r_record, '~', records.r_paraph)
SEPARATOR '|') AS clientDoctorRecords,
Try:
SELECT
client.c_id, client.c_name
doctor.d_name,
physio.p_name,
GROUP_CONCAT(records.r_record)
FROM
adm_clients AS client
INNER JOIN
norm_client_doctor AS ncd ON ncd.ncd_client_id = client.c_id
INNER JOIN
adm_doctor AS doctor ON doctor.d_id = ncd.ncd_doctor_id
INNER JOIN
norm_client_physio AS ncp ON ncp.ncp_client_id = client.c_id
INNER JOIN
adm_physio AS physio ON physio.p_id = ncp.ncp_physio_id
LEFT JOIN
adm_doctor_records AS records ON records.r_client_id = client.c_id
WHERE
client.c_id = '".$client."'
GROUP BY
client.c_id
If you want r_date to come along with record in one column, then you can use plain CONCAT first and then do a GROUP_CONCAT on it.
I have following two tables 'USERS' and 'GROUPS':
USERS
-id
-name
-groupid
GROUP
-id
-name
I'd like to return all users along with their group's name and group id. It should be an outer join on group id field correct?
A simple INNER JOIN should be enough:
SELECT `USERS`.*, `GROUP`.name AS group_name
FROM `USERS`, `GROUP`
WHERE `USERS`.groupid = `GROUP`.id
You're going to want to look at the JOIN statement
Doing this from my phone, so pardon any moderately incorrect syntax, but something a long the lines of
Edit: other guy's syntax is better. It's too early here
You can use a LEFT JOIN between users and groups so that users who are not in a group still show up in the result set, but with group name and id NULL:
SELECT
a.*,
b.name AS group_name
FROM
users a
LEFT JOIN
`group` b ON a.group_id = b.id
Side note: Ensure that you're encasing the table name group in backticks because it is a reserved keyword.
The result-set should look something like:
id | name | group_id | group_name
-----------------------------------------------------------------------------
1 | John | 5 | ThisIsGroup5
3 | Tim | 3 | ThisIsGroup3
6 | NotInGroup | NULL | NULL
Changing LEFT to INNER in the above query would INNER JOIN the two tables and exclude the user "NotInGroup" from the result-set.