I need to count how many users are in each group in a database. Unfortunately the database design is not great and the users uids are stored against the group in the group table in a LONGTEXT field column name owncloudusers.
Example of owncloudusers data :
{i:0;s:36:"25C967BD-AF78-4671-88DC-FAD935FF1B26";i:1;s:36:"40D6866B-EA06-4F39-B509-8CE551CC1924";i:2;s:36:"7724C600-DE23-45C8-8BFD-326B0138E029";i:3;s:36:"D6FF37EC-11F4-471F-94C9-F3A28416CF1F";i:4;s:36:"F70C6D03-B7BA-44E4-B703-9AF3EED9BC03";}
I thought I could use a query with a LIKE on the join to compare the user's uid and look inside owncloudusers and see if there is a match.
The closest I have got is:
SELECT T1.owncloudname, count(T2.owncloud_name) AS Users
FROM oc_ldap_group_members T1
LEFT JOIN oc_ldap_user_mapping T2 ON T1.owncloudusers LIKE('%:"'||T2.owncloud_name||'";%')
GROUP BY owncloudname;
T1 table holds the groupings and who is tagged to that group
T2 table holds the users data. column owncloud_name is the users uid column
I have tried a few approaches I found on stackoverflow CONCAT on the LIKE join and LIKE('%:"'+T2.owncloud_name+'";%')
But no joy. The current statement I have returns 0 users against all the groups but I know this is not right.
I know it much but an issue on the join not sure where to go with it next.
Any assistance would be much appreciated.
I think you need a simple
SELECT T1.owncloudname, count(*) AS Users
FROM oc_ldap_group_members T1
LEFT JOIN oc_ldap_user_mapping T2 ON T1.owncloudusers LIKE '%T2.owncloud_name%'
GROUP BY owncloudname;
If you need concat try
SELECT T1.owncloudname, count(T2.owncloud_name) AS Users
FROM oc_ldap_group_members T1
LEFT JOIN oc_ldap_user_mapping T2 ON T1.owncloudusers
LIKE concat( '%',T2.owncloud_name,'%' )
GROUP BY owncloudname;
You were close, but mysql doesn't understand || as a text concatenation operator; use CONCAT() with the text parts passed as a list of values to build the LIKE operand:
SELECT T1.owncloudname, count(T2.owncloud_name) AS Users
FROM oc_ldap_group_members T1
LEFT JOIN oc_ldap_user_mapping T2
ON T1.owncloudusers LIKE CONCAT('%;', T2.owncloud_name, ';%')
GROUP BY owncloudname;
if there aint any performance issue,
could you try it with sub-query,
SELECT
T1.owncloudname,
(SELECT COUNT(*)
FROM oc_ldap_user_mapping AS T2
WHERE LOCATE(T2.owncloud_name,T1.owncloudusers)=1) AS Users
FROM
oc_ldap_group_members T1
GROUP BY
owncloudname;
Related
I have two tables with users and I want to select the users from the first table which do not exist in the second. Can you help me?
When I use the code
Select t1.user_name From t1 Inner Join t2 On t1.user_name != t2.user_name;
I get all the users many times (actually as the number of the users - 1).
Use a LEFT JOIN instead like
Select t1.user_name From t1 left join t2
On t1.user_name = t2.user_name
where t2.user_name is null;
You can use EXISTS like this
SELECT t1.user_name FROM t1 WHERE NOT EXISTS (SELECT 1 FROM t2 WHERE t1.id = t2.id)
This example assumes that you have some sort of ID on the tables that represents the primary key and foreign key.
Not sure how are your tables designed, but having the same info (user_name) in more than one table is considered as duplication of data. To fix this, you should read about Database normalization
I've never done an inner join SQL statement before, so I don't even know if this is the right thing to use, but here's my situation.
Table 1 Columns: id, course_id, unit, lesson
Table 2 Columns: id, course_id
Ultimately, I want to count the number of id's in each unit in Table 1 that are also in Table 2.
So, even though it doesn't work, maybe something like....
$sql = "SELECT table1.unit, COUNT( id ) as count, table2.id, FROM table1, table2, WHERE course_id=$im_course_id GROUP BY unit";
I'm sure the syntax of what I'm wanting to do is a complete fail. Any ideas on fixing it?
SELECT unit, COUNT( t1.id ) as count
FROM table1 as t1 inner JOIN table2 as t2
ON t1.id = t2.id
GROUP BY unit
hope this helps.
If I understand what you want (maybe you could post an example input and output?):
SELECT unit, COUNT( id ) as count
FROM table1 as t1 JOIN table2 as t2
ON t1.id = t2.id
GROUP BY unit
Okay, so there are a few things going on here. First off, commas as joins are deprecated so they may not even be supported (depending on what you are using). You should probably switch to explicitly writing inner join
Now, whenever you have any sort of join, you also need on. You need to tell sql how it should match these two tables up. The on should come right after the join, like this:
Select *
From table1 inner join table2
on table1.id = table2.id
and table1.name = table2.name
You can join on as many things as you need by using and. This means that if the primary key of one table is several columns, you can easily create a one-to-one match between tables.
Lastly, you may be having issues because of other general syntax errors in your query. A comma is used to separate different pieces of information. So in your query,
SELECT table1.unit, COUNT( id ) as count, table2.id, FROM ...
The comma at the end of the select shouldn't be there. Instead this should read
SELECT table1.unit, COUNT( id ) as count, table2.id FROM ...
This is subtle, but the sql query cannot run with the extra comma.
Another issue is with the COUNT( id ) that you have. Sql doesn't know which id to count since table1 and table2 both have ids. So, you should use either count(table1.id) or count(table2.id)
Hi I've got data in two tables my first table contains
first name
last name
my second table contain
userid
first name
last name
I'm trying to write a sql query to get the userid of a particular user but I'm getting empty set while executing the query. Could anyone please verify that the query I'm using is right? It seems ok to me
select users.id
FROM TABLE1 AS r
LEFT JOIN TABLE2 AS users
ON (users.firstname = r.firstname
AND users.lastname=r.lastname)
You use twice the same table (TABLE2), but in the description you state that you have two tables.
I am not sure but i think you want this:
select users.id
FROM TABLE1 AS r
INNER JOIN TABLE2 AS users
ON (users.firstname = r.firstname AND users.lastname=r.lastname)
select users.id
FROM TABLE1 AS r
INNER JOIN TABLE2 AS users
ON (lower(ltrim(rtrim(users.firstname))) = lower(ltrim(rtrim(r.firstname))) AND lower(ltrim(rtrim(users.lastname)))=lower(ltrim(rtrim(r.lastname))))
Can anyone help me please? Inner join query working fine. but query displaying duplicate data. I don't to display duplicate data.
here is my query.
SELECT DISTINCT t1.class, t1.classid, t2.classid, t2.option_name
FROM table1 AS t1
INNER JOIN table AS t2 ON t1.classid = t2.classid
Here is output
"COLOR";"456";"456";"Nude"
"COLOR";"456";"456";"Ivory"
"COLOR";"456";"456";"Black"
"COLOR";"456";"456";"Coral"
"COLOR";"459";"459";"Black"
"COLOR";"459";"459";"Coral"
"COLOR";"459";"459";"Nude"
"COLOR";"459";"459";"Ivory"
"SIZE";"460";"460";"Large"
"SIZE";"460";"460";"Medium"
"SIZE";"460";"460";"Small"
"SIZE";"470";"470";"Large"
"SIZE";"470";"470";"Small"
"SIZE";"470";"470";"Medium"
"COLOR";"476";"476";"White"
"COLOR";"476";"476";"Black"
"SIZE";"477";"477";"Small"
But i don't to display duplicate data. for example which is displaying here.
"COLOR";"459";"459";"Black"
"COLOR";"459";"459";"Black"
"COLOR";"459";"459";"Black"
"COLOR";"460";"60";"Black"
is there any way?? thanks
Maybe you just want to group it by names? You seem to be calling a duplicated data what seems to have different ids...
SELECT DISTINCT t1.class, t1.classid, t2.classid, t2.option_name
FROM table1 AS t1
INNER JOIN table AS t2 ON t1.classid = t2.classid
GROUP BY t1.class,t2.option_name
I want to do a sql query and have some problems:
I want to salect from table_1 the ID's Where parent_id is the value I have:
SELECT ID FROM table_1 WHERE parent_ID = 'x'
I want to use the ID'S I got in 1. and
SELECT FROM table_2 WHERE ID = 'The ID's from Query 1.
Simple and Execute
Select t1.`id` FROM table t1 INNER JOIN table t2 ON t1.`id`=t2.`id`
As Bainternet mentioned you can do this with a subquery
SELECT * FROM table_2 WHERE ID IN (SELECT ID FROM table_1 WHERE parent_ID = 'x')
Though your idea to use an inner join is also good (especially since MySQL can be slow when processing subqueries).
SELECT t2.* FROM table_2 as t2 INNER JOIN table_1 AS t1 ON t2.ID = t1.ID WHERE t1.parent_ID = 'x'
If that's not clear, try looking at the MySQL JOIN Syntax or the Subqueries, as Bainternet mentioned. If these examples and the MySQL docs aren't clear enough for you, consider posting more details on exactly what you're trying to do (e.g. include table structures in your question). Also while you might want this information for some WordPress related work you are doing, there's nothing in the question itself that actually ties it to WordPress. So if you have more questions that about MySQL queries in general, then you might want to consider posting them to the StackOverflow, tagged as mysql-query.