I have 3 mysql tables:
Users:
id | name | interest | user_id
1 | user1 | 1,2 | 1
2 | user2 | 1,2,3 | 2
Interests:
id | name
1 | interest1
2 | interest2
User_posts:
id | user_id | desc
1 | 23 | something..
2 | 31 | something..
What i want to achieve is i want join interest column from users table into user_posts table based on user_id with user_name from interests table which i have already done using this query:
select user_posts.*, users.interest as interest_ids, zaya.interests.name as interest_name
from user_posts
left join users ON user_posts.id = users.interest
left join interests ON user_posts.id = users.interest;
i get the following output with this query:
User_posts:
id | user_id | desc | interest_ids | interest_name
1 | 23 | something.. | 1,2 | interest1
2 | 31 | something.. | 1,2,3 | interest1
Output i want to achieve:
User_posts:
id | user_id | desc | interest_ids | interest_name
1 | 23 | something.. | 1,2 | interest1, interest2
2 | 31 | something.. | 1,2,3 | interest1, interest2, interest3
I believe this can be solved using the temporary table creation method and have tried solving this but i'm newbie in mysql queries and getting errors please help me with the correct query.
Thank you in advance.
I would use a sub query rather than a join if you're looking to just get back one col form the [interests] table.
Here is an example using STRING_SPLIT function to get the names :
DECLARE #users TABLE(
[ID] int IDENTITY(1,1)
,[NAME] varchar(32)
,[INTERESTS] varchar(32)
)
INSERT INTO #users
VALUES ('user1', '1,2'), ('user2', '1,2,3')
DECLARE #interests TABLE(
[ID] int IDENTITY(1,1)
,[NAME] varchar(32)
)
INSERT INTO #interests
VALUES ('interests1'), ('interests2'), ('interests3')
DECLARE #user_posts TABLE(
[ID] int IDENTITY(1,1)
,[USERID] int
,[DESC] varchar(32)
)
INSERT INTO #user_posts
VALUES (1, 'post1'), (2, 'post2')
SELECT
U.[ID]
,UP.[USERID]
,UP.[DESC]
,U.[INTERESTS]
,SUBSTRING((SELECT ',' + I2.[NAME]
FROM #interests I2
WHERE I2.[ID] IN (SELECT [name] FROM STRING_SPLIT(U.[INTERESTS], ','))
FOR XML PATH('')), 2, 1000) AS 'INTEREST_NAME'
FROM #user_posts UP
LEFT JOIN #users U
ON U.[ID] = UP.[USERID]
This should return :
ID
USERID
DESC
INTERESTS
INTEREST_NAME
1
1
post1
1,2
interests1,interests2
2
2
post2
1,2,3
interests1,interests2,interests3
Related
I have 3 tables
User Info
id
name
1
bob
2
jane
3
tom
Locations
id
name
1
Test1
2
Test2
3
Test3
4
Test4
User Locations
userID
locationID
1
1
1
2
2
3
Basically What I am trying to achieve is to pull the location names where the user doesn't have it bound already.
In the above list Bob has 2 locations bounded "test 1" and "test 2" but he doesn't have "test 3" or "test 4" yet. I Only want the data to return test 3 and 4 since those are the only ones Bob doesn't have.
For Jane She only has Test 3 bounded but none of the remaining 3
Originally I had tried this and it somewhat worked. However Every time another user gets an unbounded location the its removed from the list. I'm not sure how I would add the user ID in all this so it's only specific to that user.
SELECT `name` FROM `locations`
WHERE `id` NOT IN (SELECT `locationID` FROM `user_locations`)
Create a cartesain product of the user and locations table (cross join), then using an outer join allows us to find rows that are as yet unmatched in user_locations:
select
user_info.ID AS UserID
, locations.ID AS locationID
from user_info
cross join locations
left outer join user_locations on user_info.id = user_locations.userid
and locations.id = user_locations.locationid
where user_locations.userid IS NULL
and user_info.name = 'bob'
SQL Fiddle
MySQL 5.6 Schema Setup:
CREATE TABLE user_info(
id INTEGER NOT NULL PRIMARY KEY
,name VARCHAR(4) NOT NULL
);
INSERT INTO user_info(id,name) VALUES (1,'bob');
INSERT INTO user_info(id,name) VALUES (2,'jane');
INSERT INTO user_info(id,name) VALUES (3,'tom');
CREATE TABLE locations(
id INTEGER NOT NULL PRIMARY KEY
,name VARCHAR(5) NOT NULL
);
INSERT INTO locations(id,name) VALUES (1,'Test1');
INSERT INTO locations(id,name) VALUES (2,'Test2');
INSERT INTO locations(id,name) VALUES (3,'Test3');
INSERT INTO locations(id,name) VALUES (4,'Test4');
CREATE TABLE user_locations(
userID INTEGER NOT NULL
,locationID INTEGER NOT NULL
);
INSERT INTO user_locations(userID,locationID) VALUES (1,1);
INSERT INTO user_locations(userID,locationID) VALUES (1,2);
INSERT INTO user_locations(userID,locationID) VALUES (2,3);
Query 1:
select
user_info.ID AS UserID
, locations.ID AS locationID
from user_info
cross join locations
left outer join user_locations on user_info.id = user_locations.userid
and locations.id = user_locations.locationid
where user_locations.userid IS NULL
order by 1,2
Results:
| UserID | locationID |
|--------|------------|
| 1 | 3 |
| 1 | 4 |
| 2 | 1 |
| 2 | 2 |
| 2 | 4 |
| 3 | 1 |
| 3 | 2 |
| 3 | 3 |
| 3 | 4 |
I have this table:
CREATE TABLE one (
id bigint(11) primary key,
email varchar(100),
refer_link varchar(8),
referrer varchar (8)
);
When users submit forms they get a unique refer link (refer_link). When another user submit forms with that link in his referrer column is inserted that refer link.
So in example I will have this table:
id email refer_link referrer
---------------------------------------------------------
1 jerry#jerry.com ref11111
2 elaine#elaine.com ref22222 ref11111
3 george#george.com ref33333 ref22222
4 kramer#kramer.com ref44444 ref11111
5 cosmo#cosmo.com ref55555 ref44444
How to create this view?
email refer_email refer_count
--------------------------------------------------------
jerry#jerry.com 2
elaine#elaine.com jerry#jerry.com 1
george#george.com elaine#elaine.com 0
kramer#kramer.com jerry#jerry.com 1
cosmo#cosmo.com kramer#kramer.com 0
Thank you very much for help!
Try the below sub query,
$query = "select o.email,
IFNULL( (select email from one where o.referrer = refer_link ),'') as refer_email,
(select count(referrer) from one where referrer = o.refer_link ) as refer_count
from one as o order by id ";
DROP TABLE IF EXISTS my_table;
CREATE TABLE my_table
(id SERIAL PRIMARY KEY
,email VARCHAR(50) NOT NULL
,referrer INT NULL
);
INSERT INTO my_table VALUES
(1,'jerry#jerry.com',NULL),
(2,'elaine#elaine.com',1),
(3,'george#george.com',2),
(4,'kramer#kramer.com',1),
(5,'cosmo#cosmo.com',4);
SELECT x.*, COUNT(y.id) refer_count FROM my_table x LEFT JOIN my_table y ON y.referrer = x.id GROUP BY x.id;
+----+-------------------+----------+-------------+
| id | email | referrer | refer_count |
+----+-------------------+----------+-------------+
| 1 | jerry#jerry.com | NULL | 2 |
| 2 | elaine#elaine.com | 1 | 1 |
| 3 | george#george.com | 2 | 0 |
| 4 | kramer#kramer.com | 1 | 1 |
| 5 | cosmo#cosmo.com | 4 | 0 |
+----+-------------------+----------+-------------+
I have 2 tables.
CREATE TABLE designs
( game_id INT NOT NULL,
des_id INT NOT NULL,
PRIMARY KEY(game_id, des_id),
FOREIGN KEY(game_id) REFERENCES Game(id),
ON UPDATE CASCADE)
CREATE TABLE designer
( name VARCHAR(30) NOT NULL,
id INT NOT NULL,
PRIMARY KEY(id),
FOREIGN KEY(id) REFERENCES designs(des_id),
ON UPDATE CASCADE);
Lets say I have data:
designs:
0---0
0---1
1---2
2---3
2---4
.............................
designer:
Bob---0
Jill---1
Bob---2
Rob---3
Jill---4
After the update, I would like the "designs" table to look like:
0---0
0---1
1---0
2---3
2---1
What update query would I need to accomplish this?
Some queries I tried are:
UPDATE designs
SET des_id = (
SELECT a.id
FROM designer as a
JOIN designer as b
ON a.name=b.name AND a.id < b.id
WHERE des_id = b.id);
...
UPDATE `designs` as a
JOIN designer as b
ON a.des_id=b.id
SET a.des_id = b.id
WHERE b.id = (
SELECT c.id
FROM designer as c
LEFT JOIN designer as d
ON c.name=d.name
WHERE c.id<d.id)
Here's one idea. Note that it uses an documented hack in the form of a 'group by/order by' trick:
UPDATE designs d
JOIN
( select d1.id matcher_id
, d2.id select_id
from `designer` d1
JOIN designer d2
ON d1.name = d2.name
group
by d1.id
Order
by d2.id
) x
ON x.matcher_id = d.des_id
SET d.des_id = select_id
Your LEFT JOIN idea is almost right, but here's another idea which is faster...
DROP TABLE IF EXISTS designs;
CREATE TABLE designs
( game_id INT NOT NULL
, designer_id INT NOT NULL
, PRIMARY KEY(game_id, designer_id)
);
DROP TABLE IF EXISTS designers;
CREATE TABLE designers
( name VARCHAR(30) NOT NULL
, designer_id INT NOT NULL AUTO_INCREMENT PRIMARY KEY
);
INSERT INTO designs VALUES
(1,1),
(1,2),
(2,3),
(3,4),
(3,5);
INSERT INTO designers VALUES
('Bob',1),
('Jill',2),
('Bob',3),
('Rob',4),
('Jill',5);
SELECT * FROM designs;
+---------+-------------+
| game_id | designer_id |
+---------+-------------+
| 1 | 1 |
| 1 | 2 |
| 2 | 3 |
| 3 | 4 |
| 3 | 5 |
+---------+-------------+
SELECT * FROM designers;
+------+-------------+
| name | designer_id |
+------+-------------+
| Bob | 1 |
| Jill | 2 |
| Bob | 3 |
| Rob | 4 |
| Jill | 5 |
+------+-------------+
UPDATE designs g
JOIN designers d
ON d.designer_id = g.designer_id
JOIN designers x ON x.name = d.name
JOIN
( SELECT name
, MIN(designer_id) min_designer_id
FROM designers
GROUP
BY name
) y
ON y.name = x.name
AND y.min_designer_id = x.designer_id
SET g.designer_id = x.designer_id;
SELECT * FROM designs;
+---------+-------------+
| game_id | designer_id |
+---------+-------------+
| 1 | 1 |
| 1 | 2 |
| 2 | 1 |
| 3 | 2 |
| 3 | 4 |
+---------+-------------+
Actually, in the special case of an UPDATE, I think this will work just as well, and I'm not really sure that it's any less performative...
UPDATE designs g
JOIN designers x
ON x.designer_id = g.designer_id
JOIN designers y
ON y.name = x.name
AND y.designer_id < x.designer_id
SET g.designer_id = y.designer_id;
Firstly, pardon the incredibly vague/long question, I'm really not sure how to summarise my query without the full explanation.
Ok, I have a single MySQL table with the format like so
some_table
user_id
some_key
some_value
If you imagine that, for each user, there are multiple rows, for example:
1 | skill | html
1 | skill | php
1 | foo | bar
2 | skill | html
3 | skill | php
4 | foo | bar
If I want to find all the users who have listed HTML as a skill I can simply do:
SELECT user_id
FROM some_table
WHERE some_key = 'skill' AND some_value='html'
GROUP BY user_id
Easy enough. This would give me user ID's 1 and 2.
If I want to find all users who have listed HTML or PHP as a skill then I can do:
SELECT user_id
FROM some_table
WHERE (some_key = 'skill' AND some_value='html') OR (some_key = 'skill' AND some_value='php')
GROUP BY user_id
This would give me use ID's 1, 2 and 3.
Now, what I'm struggling to work out is how I can query the same table but this time say "give me all the users who have listed both HTML and PHP as a skill", i.e: just user ID 1.
Any advice, guidance or links to docs massively appreciated.
Thanks.
Here's one way:
SELECT user_id
FROM some_table
WHERE user_id IN (SELECT user_id FROM some_table where (some_key = 'skill' AND some_value='html'))
AND user_id IN (SELECT user_id FROM some_table where (some_key = 'skill' AND some_value='php'))
you need to use a nested query (or a self join, which is different)
I set up the following table.
+-------+----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+-------+
| id | int(11) | YES | | NULL | |
| type | char(10) | YES | | NULL | |
| value | char(10) | YES | | NULL | |
+-------+----------+------+-----+---------+-------+
inserted the following values
+------+-------+-------+
| id | type | value |
+------+-------+-------+
| 1 | skill | html |
| 1 | skill | php |
| 2 | skill | html |
| 3 | skill | php |
| 2 | skill | php |
+------+-------+-------+
ran this query
select id
from test
where type = 'skill'
and value = 'html'
and id in (
select id
from test
where type = 'skill'
and value = 'php');
and got
+------+
| id |
+------+
| 1 |
| 2 |
+------+
a self join would be as follows
select e1.id
from test e1, test e2
where e1.id = e2.id
and e2.type = 'skill'
and e2.value = 'html'
and e1.type = 'skill'
and e1.value = 'php'
;
and produce the same result.
so there you have two ways to try it in your code.
I don't know if this is valid for mysql, but should be (works for other db engines):
SELECT php.user_id
FROM some_table php, some_table html
WHERE php.user_id = html.user_id
AND php.some_key = 'skill'
AND html.some_key = 'skill'
AND php.some_value = 'php'
AND html.some_value = 'html';
And alternative, by using HAVING statement:
SELECT user_id, count(*)
FROM some_table
WHERE some_key = 'skill'
AND some_value in ('php','html')
GROUP BY user_id
HAVING count(*) = 2;
And a third option is to use inner selects. A slight alternative approach to David's approach:
SELECT user_id FROM some_table
WHERE
some_key = 'skill' AND
some_value = 'html' AND
user_id IN (
SELECT user_id FROM some_table
WHERE
some_key = 'skill' AND
some_value = 'php' AND
user_id IN (
SELECT user_id FROM some_table
WHERE
some_key = 'skill' AND
some_value = 'js' -- AND user_id IN ... for next level, etc.
)
);
... idea is that you can "pipe" the inner selects. With each new property you add new inner select to the most inner one.
The behaviour I want to replicate is like grep with -A and -B flags .
eg grep -A 2 -B 2 "hello" myfile.txt will give me all the lines which have "hello" in them, but also 2 lines before and 2 lines after it.
Lets assume this table schema :
+--------+-------------------------+
| id | message |
+--------+-------------------------+
| 1 | One tow three |
| 2 | No error in this |
| 3 | My testing message |
| 4 | php module test |
| 5 | hello world |
| 6 | team spirit |
| 7 | puzzle game |
| 8 | social game |
| 9 | stackoverflow |
|10 | stackexchange |
+------------+---------------------+
Now a query like :
Select * from theTable where message like '%hello%' will result in :
5 | hello world
How can I put another parameter "N" which selects N rows before, and N rows after the matched record i.e. for N = 2, the result should be :
| 3 | My testing message |
| 4 | php module test |
| 5 | hello world |
| 6 | team spirit |
| 7 | puzzle game |
For simplicity assume 'like %TERM%' matches only 1 row .
Here the result is supposed to be sorted on auto-increment id field.
Right, this works for me:
SELECT child.*
FROM stack as child,
(SELECT idstack FROM stack WHERE message LIKE '%hello%') as parent
WHERE child.idstack BETWEEN parent.idstack-2 AND parent.idstack+2;
Don't know if this is at all valid MySQL but how about
SELECT t.*
FROM theTable t
INNER JOIN (
SELECT id FROM theTable where message like '%hello%'
) id ON id.id <= t.id
ORDER BY
ID DESC
LIMIT 3
UNION ALL
SELECT t.*
FROM theTable t
INNER JOIN (
SELECT id FROM theTable where message like '%hello%'
) id ON id.id > t.id
ORDER BY
ID
LIMIT 2
Try this simple one (edited) -
CREATE TABLE messages(
id INT(11) DEFAULT NULL,
message VARCHAR(255) DEFAULT NULL
);
INSERT INTO messages VALUES
(1, 'One tow three'),
(2, 'No error in this'),
(3, 'My testing message'),
(4, 'php module test'),
(5, 'hello world'),
(6, 'team spirit'),
(7, 'puzzle game'),
(8, 'social game'),
(9, 'stackoverflow'),
(10, 'stackexchange');
SET #text = 'hello world';
SELECT id, message FROM (
SELECT m.*, #n1:=#n1 + 1 num, #n2:=IF(message = #text, #n1, #n2) pos
FROM messages m, (SELECT #n1:=0, #n2:=0) n ORDER BY m.id
) t
WHERE #n2 >= num - 2 AND #n2 <= num + 2;
+------+--------------------+
| id | message |
+------+--------------------+
| 3 | My testing message |
| 4 | php module test |
| 5 | hello world |
| 6 | team spirit |
| 7 | puzzle game |
+------+--------------------+
N value can be specified as user variable; currently it is - '2'.
This query works with row numbers, and this guarantees that the nearest records will be returned.
Try
Select * from theTable
Where id >=
(Select id - variableHere from theTable where message like '%hello%')
Order by id
Limit (variableHere * 2) + 1
(MS SQL Server only)
The most reliable way would be to use the row_number function that way it doesn't matter if there are gaps in the id. This will also work if there are multiple occurances of the search result and properly return two above and below each result.
WITH
srt AS (
SELECT ROW_NUMBER() OVER (ORDER BY id) AS int_row, [id]
FROM theTable
),
result AS (
SELECT int_row - 2 AS int_bottom, int_row + 2 AS int_top
FROM theTable
INNER JOIN srt
ON theTable.id = srt.id
WHERE ([message] like '%hello%')
)
SELECT theTable.[id], theTable.[message]
FROM theTable
INNER JOIN srt
ON theTable.id = srt.id
INNER JOIN result
ON srt.int_row >= result.int_bottom
AND srt.int_row <= result.int_top
ORDER BY srt.int_row
Adding an answer using date instead of an id.
The use-case here is an on-call rotation table with one record pr week.
Due to edits the id might be out of order for the purpose intended.
Any use-case having several records pr week, pr date or other will of course have to be mended.
+----------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| startdate| datetime | NO | | NULL | |
| person | int(11) | YES | MUL | NULL | |
+----------+--------------+------+-----+---------+----------------+
The query:
SELECT child.*
FROM rota-table as child,
(SELECT startdate
FROM rota-table
WHERE YEARWEEK(startdate, 3) = YEARWEEK(now(), 3) ) as parent
WHERE
YEARWEEK(child.startdate, 3) >= YEARWEEK(NOW() - INTERVAL 25 WEEK, 3)
AND YEARWEEK(child.startdate, 3) <= YEARWEEK(NOW() + INTERVAL 25 WEEK, 3)