If I want to make an update query using INNER JOIN, how do I do in this case:
I have a users table & user_settings table. users contains column id and user_settings contains column userid. I want to do like:
UPDATE users_settings SET commets = 0 WHERE email = "$email";
But user_settings does not contain email, so I want to pick the email from the users table where the id is userid.
You can use this query. it will work
UPDATE users_settings SET commets = 0 WHERE userid
IN (SELECT id FROM users WHERE email = "$email");
The following will be helpful
UPDATE US SET US.Comments = 0
FROM User_settings US, Users U
WHERE US.Userid = U.id
AND U.email = 'emailid'
JOINs are slightly better in terms of performance than SUB QUERIES. Reference here.
So instead of using this -
UPDATE users_settings SET commets = 0 WHERE userid
IN (SELECT id FROM users WHERE email = "$email");
I would suggest this using INNER JOIN -
UPDATE users_settings
SET commets = 0
FROM user_settings
INNER JOIN users
on users.id = user_settings.userid --JOIN CONDITION
WHERE users.email = "$email" ; --SELECTION/SLICING CRITERION
Hope this helps.
Try this:
UPDATE user_settings s
INNER JOIN users u ON s.userid=u.id
SET s.commets = 0 WHERE u.email = "$email";
Note: There should be no users with the same e-mail in these cases.
Related
I've tried to get data from from one table if id of 2 tables equals to each other. Here is the code which I used:
SELECT id_to
, email_to
, name_to
, status_to
FROM users
LEFT
JOIN friends
ON users.id = friends.id_from
WHERE id_from = ?
I used LEFT JOIN to join two tables but it gets the values from the friends(table) instead of users(table).
I think I've explained my problem clearly.
I guess you must specify it on your query, like this:
SELECT users.id_to, users.email_to, users.name_to, user.status_to FROM users LEFT JOIN friends ON users.id = friends.id_from WHERE id_from = ?
You can do the same if you need to retrieve values from 'friends' table.
If both tables have the same column, then you can specify the table name while selecting columns. so your code will look like:
SELECT users.id_to, users.email_to, users.name_to, user.status_to FROM users LEFT JOIN friends ON users.id = friends.id_from WHERE friends.id_from = ?
I made a query that user can see all the post of active users but not of those inactive, but also they should not see the post of users they blocked or blocked them how can I do that?, the block_users table has block_by_userid and blocked_userid column.
I tried INNER JOIN the post table with members table which every inactive users post cannot be seen anymore., How will I combine the block_users table?
$GetPost = "SELECT Post.* FROM Post
INNER JOIN Members ON Post.Poster_user_id = Members.User_id
WHERE Status='active'";
you might try FULL OUTER JOIN
the idea it to get all items in both tables member and block_users and then filter the data using where clause, i am sorry if i miss using the fields name , so please check the tables names, i assume block_users.block_by_userid contained the blocked user id if not use the correct field
$GetPost = "SELECT Post.* FROM Post
INNER JOIN Members ON Post.Poster_user_id = Members.User_id
FULL OUTER JOIN block_users ON Members.User_id = block_users.user_id
WHERE Status='active'
AND
WHERE block_users.block_by_userid != Members.User_id";
Suppose I am doing this for a user xyz whose user_id is 123 then below is a query which will return expected output for user 123.
Query:
SELECT Post.* FROM Post
INNER JOIN Members ON Post.Poster_user_id = Members.User_id
WHERE Status='active' and post.poster_user_id NOT IN(select block_by_userid from block_users where blocked_user_id = 123 UNION select blocked_user_id from block_users where block_by_userid = 123)
i need help getting data from different tables and insert into other different table Here are the Queries
"SELECT commentID, date, comment, subject, parentID, aBUserID FROM comments WHERE status = 'APPROVED'"
"SELECT topicID, subForumID, aBUserID, lastPostID, views, replies, startDate FROM topic WHERE status = 'APPROVED' AND topicID = $parentid";
// $parentID need to be matched from above query parentID,
"SELECT userName FROM users WHERE aBUserID = $cmtaBUserID";
// $cmtaBUserID = aBUserID from first query
"SELECT userName FROM users WHERE aBUserID = $topicaBUserID";
//$topicaBUserID = aBUserID from second query
Last 2 queries are from same table but using different where clause
i used different inner join left join from solutions posted here but non of these worked for me stuck since last 2 weeks please help
PS data from all above Queries will be inserted to a single table i need these to be combined so i can have them all in one place
If you want to perform the operation in same query use 'OR'
"SELECT userName FROM users WHERE aBUserID = $cmtaBUserID OR aBUserID = $topicaBUserID";
Please try this
SELECT userName from users where aBUserID IN(SELECT aBUserID FROM comments WHERE status = 'APPROVED')
Couldn't test it but Maybe this is what you are looking for.
SELECT c.commentID, c.date, c.comment, c.subject, c.parentID, c.aBUserID,
t.topicID, t.subForumID, t.aBUserID, t.lastPostID, t.views, t.replies, t.startDate,
u.userName
FROM
comments c
left outer join topic t on t.topicID = c.parentID
left outer join users u on u.aBUserID = c.aBUserID and u.aBUserID = t.aBUserID
WHERE
c.status = 'APPROVED' and t.status = 'APPROVED';
try this:
SELECT
comment.[commentID],
comment.[date],
comment.[comment],
comment.[subject],
comment.[parentID],
comment.[aBUserID],
commentuser.[userName],
topic.[topicID],
topic.[subForumID],
topic.[aBUserID],
topic.[lastPostID],
topic.[views],
topic.[replies],
topic.[startDate],
topic.[userName]
FROM comments comment
LEFT OUTER JOIN users commentuser
ON commentuser.aBUserID = comment.[aBUserID]
LEFT OUTER JOIN
(
SELECT
t.[topicID],
t.[subForumID],
t.[aBUserID],
t.[lastPostID],
t.[views],
t.[replies],
t.[startDate],
u2.[userName] --user from users table joined to topics table
FROM topic t
LEFT OUTER JOIN users u
ON u.aBUserID = t.[aBUserID]
WHERE t.[status] = 'APPROVED'
) topic
ON topic.topicID = comment.parentID
WHERE comment.[status] = 'APPROVED'
I have a user table, e.g.
userId
userName
and I have a message table, e.g.
messageId
messageToId
messageFromId
messageContent
I am trying to make a query to pull a message, but also get the user names from the user table based on the messageToId and messageFromId.
I have done this before with only 1 field between tables, e.g.
SELECT message.*, user.userName
FROM message, user
WHERE user.userId = message.messageToId
AND messageId = (whatever)
But I am having trouble with 2 links.
I want the result as follows:
messageId
messageToId
toUserName
messageFromId
fromUserName
messageContent
Any help would be much appreciated, or if someone had another way of attempting a private message system with PHP/MySQL.
You just have to use joins and different table aliases:
SELECT m.*, u1.userName AS toUserName, u2.username AS fromUserName
FROM message m INNER JOIN user u1 ON m.messageToId = u1.userId
INNER JOIN user u2 ON m.messageFromId = u2.userId
WHERE messageId = "XXX";
You need to use a join from to achieve this:
SELECT `m`.*,
`to`.`userName` AS `to`,
`from`.`userName` AS `from`,
FROM `message` `m`
JOIN `user` `to` ON `m`.`messageToId` = `to`.`userId`
JOIN `user` `from` ON `m`.`messageFromId` = `from`.`userId`
WHERE `m`.`messageId` = 1
So you join against the user table twice to get both users for a particular message. To do this you need to use table aliases as I have done with to and from so that you distinguish between them.
I have also used a field alias to get their usernames separately eg:
`to`.`username` AS `from`
Will this work?
SELECT b.userName AS author, c.userName AS reciever, a.messageId, a.messageContent FROM message a JOIN user b ON a.messageFromId = b.userId JOIN user c ON a.messageToId = c.userId
Yes so im building an query from the advanced search form.
I have this:
$query = "SELECT * FROM users WHERE 1 ";
$query .= "AND sex = '$sex' ";
for now, next im going to have AND birthday.. but then i dont know how to do it, because users birthday is stored in users_profile
So please correct me, how can i:
$query .= "AND birthday in users_profile = '1'";
Is this possible even, or should i reconstruct it and put birthday in users instead..
update:
in users, the id column there, is binded with users_profile´s uID.
So in users_profile´s uID column, there is the users id.
I assume your users_profile table is linked to the users table?
SELECT u.*, up.birthday
FROM users u
INNER JOIN users_profile up
ON u.user_id = up.user_id
WHERE sex = '$sex'
Here an Inner Join is used. The reason we can use u instead of users and up instead of users_profile is because we have set up the aliases "users u" and "users_profile up"
You need to look at the syntax for JOIN.
You need a way to join individual related rows in the two tables, something like:
SELECT u.* FROM users u, users_profile p
WHERE u.sex = 'M'
AND p.birthday = '1'
AND u.userid = p.userid;
I don't understand why you have separate tables for user and for users_profile, but you need to JOIN the two tables:
SELECT U.*
FROM users U
LEFT JOIN users_profile P
ON P.uID = U.uID
AND P.birthday = '1'
WHERE U.sex = '$sex'
Very possible, given you have the foreign key to the users_profile table.
Let's say the primary key in the users table is named 'id', and the users_profile table contain a field called 'uid' which point to the users table, you'd normally create the query like this:
SELECT * FROM users u, users_profile p WHERE u.id = p.uid
AND u.sex = '$sex' AND u.birthday = 1