I'm new on programming, sorry if I can't explain my doubt very well...
My friend have a online game and I help him to manage it. The php has a table for the users (meh_users), and a table for the items that the users have (meh_users_items). Each item has a id, (column itemid) and also the users (column userid), and in the table of the items that the users have, there is a id for the combination of the user and the item. (just id, and sorry, I don't understand this so much).
There is an image, if this make more easy to understand me:
phpMyAdmin printscreen
I want to add an item (let's think that it's a sword and this item have the id 3454) to all the users, but I don't want to delete the other items that the users have. Also I don't want to insert the data on the table one by one, because it's more than a hundred users.
Hope I have said enough details!
Remember: I'm new and I already search soooo much in the internet before asking here.
I suppose you want to give that sword to all users, including ones that already have it. You don't need PHP for this, SQL is enought.
INSERT INTO meh_users_items (userid, itemid, equipped)
SELECT userid, 3454, 0
FROM meh_users
This is just an example. You need to add all field to SQL.
Three steps:
If it isn't there already, add the new item (e.g., the Sword of Power) to your meh_items table.
Get a list of all your users from the meh_user table.
Write a foreach statement creating an entry in the meh_users_items table for each user.
It also occurs to me that your database might have some setup issues. E.g., meh_users_items has a column indicating item type (e.g., weapon). That could end up being problematic. Better to keep that information with the items in the meh_items table.
Related
So I have two different tables, a users table and an articles table. The idea is to allow a user to rate an article, but only allow them to rate it once (possible change their existing rating too but I can come to that conclusion later).
As of now I just have the update value working to allow them to rate the article, but of course a user can rate an article as many times as they want.
To give you an idea of how I have everything working, when a user logins in, a session is created with their user information. So when they go to rate an article, I have the ability to check the user, I just don't know how to stop them from rating if they have already rated a specific article.
The user table consists of among other things their username and their unique ID
and the article table consists among other things the article contents, the article unique ID, and the articles rating.
I had some really sloppy ideas like when the user rates an article their ID gets stored into the articles row in some kind of "users who have rated" column, and then I can do a for loop or something to siphon out all the user IDs and then check if their ID exists in that articles entry but then each article would have a row with possibly hundreds or thousands of userIDs on it and there seems like there would be a more elegant way.
Any help or direction is appreciated :)
Create a UserRatings table which has foreign keys to the users table and the articles table, and stores a row linking the user to the article, and the rating they gave it and when it occurred.
Then if a user tried to rate it again you just check this table for the user ID/article ID combination before allowing it.
And then if you wanted got can do things like show the user a list of articles they have previously rated, etc
I have three tables, and I'm just looking for a way to make this work.
tbl_campaigns has the columns "id" and "campaign". This one is fairly straight forward, it's just campaign names with an ID number that is auto-incremented so they have unique IDs.
tbl_users has an "id" column so each user has a unique ID number, standard stuff.
tbl_permissions creates a new row whenever a new user is created. This means its "id" column has unique ID values that match to the ID of a user in 'tbl_users'. The columns have been named to match the ID value of a campaign each time a new one is created, for example, the column "campaign_1" is relevant to the campaign in 'tbl_campaigns' with the ID of 1. The idea is this table data is filled with either 1's or 0's.
If a row with the ID of 1 has the number 1 for the column "campaign_1", then the user with the ID of 1 is approved for the campaign with the ID of 1 in the campaign table. If it were 0 then they're not approved for it. The same logic applies for columns "campaign_2", "campaign_3" etc..
Anyways, the issue I'm having is displaying this information on a front-end, as I only want the user to be able to see the campaigns they are approved to run in a drop-down list. When the user is logged in it stores their User ID in a session, I'm not sure if there's a way around it with this method.
Is there any way to get around this? Please note I've done this in procedural PHP as I'm still in my early days, so if anyone has a solution along these lines it would be much appreciated. Sorry if it's a little confusing. I am aware it's a bit ham-fisted, but I just want it to work first.
I believe that your schema needs to be improved, as the table structure should not have to change every time that you add a new campaign.
keep tables tbl_campaigns and tbl_users as they are
create table tbl_permissions with 4 fields (id, user_id, campaign_id and permission)
To check if a user has permission use a query like this:
SELECT permission FROM tbl_permissions WHERE user_id = ? AND campaign_id = ?
So, every time you create a campaign add a corresponding record to the tbl_permissions table. No need to add a new column.
I think the best practice to do this is as follows:
- Create HTML to show to the user(if you don't have it, let me know so i can work on one you can use)
- Create JS archive that will be in charge of calling PHP file and show the result in your HTML(if you don't know how to make it let me know so i can help you)
- Create PHP file, this is going to be in charge of consulting your data base and give the result disired for your select (if you don't know how to make it, let me know)
It is pretty easy to make this work, let me know if you need more help.
I'm currently coding a blog to get experience with php(I've made an MVC-Framework), so I am still new to this.
I have two tables important for this question:
user(id, username, password, registrated)
comments(id, content, post_id, comment_author, date, editedAt, editedBy)
In the comments-table comment_author is yet not linked to the id of the user, because I was unsure how to actually do this.
A user can write as many comments as he likes, but a comment can only have one author.
comment_author has the username in it at the moment, but I know I need the id(if the user gets deleted and someone else would registrate with this username, the comment would be his).
How should I now structure the tables?
1.) comments_author_id in comments-table, id in user as foreign key:
In this case I would have the id of the Comment author in the comments-table, but the user would not know about the comments he has written. If I want to show the recent comments of the user on it's profile, could I get them with an inner-join query then?
2.) make a new table user_comments(id, user_id, comment_id)
In this case user and comments wouldn't know about it's author/comments.
Also I have 'editedBy' in which the username of the last editing user is. Can I somehow link it with the username in the users-table or should I also link it with the id?
I am really lost with this question since I don't know much about databases; So I appreciate every help and advice I can get.
Please also let me know if I need to give any further information or change something for a better understanding.
It make sense that you go with the first option.
As you said comment has only one author so just use a foreignkey to user table.
In the second option you're creating a hole new table for a data that doesn't need a new table so you're storing data's that you don't need. also you have to write in two different tables which is two different operations for adding a comment and it gives you no extra feature that you can use.
Best way is create a new table user_comments(id, user_id, comment_id). And if you want to track every changed/edit the comment or post it's will better if you create another table for that and if user can only edit then i think it's better to editedBy fields not generate. The structure totally upto you what kind of tracking you want to be .
I'm sort of working on a CMS type structure. I've got to the point where mostly everything is in place except for small things that I keep pondering on like this one.
So let us suppose there is a user table and an articles table. Now, ofcourse if someone 'likes' an article, the user's ID will be stored in a column in the article's table. Something like this 11241,12412,12312. (these are random user IDs)
Now lets say that there's a user's profile page as well and I want to iterate through the user's liked posts and display it there.
Now, I've thought up of 2 ways of doing this.
First method being that the article IDs that the user has liked are stored in the user's table in his row and we get it from that but this seems sort of inefficient. Because if the user has liked a lot of articles, then I could run out of space in the column of the database?
Second method would be to go through every article and see if the user's ID exists in the list of likers saved of the article. However this method would be really slow and a really bad practice, IMO.
So what's the best practice for this?
Create a table that has two columns: user_id and article_id. When a user “likes” an article, insert a row into this table. Then when you want to see which articles user #123 has liked, you can just issue a query like this:
SELECT `article_id` FROM `article_user` WHERE `user_id` = '123';
If you need the article data, it’s easy enough to just join on the article_id column:
SELECT `article`.*
FROM `article`
LEFT JOIN `article_user` ON `article`.`id` = `article_user`.`article_id`
WHERE `article_user`.`user_id` = '123';
I've been racking my brain over this for a few days now, and being fairly new to 'back end' stuff, I haven't managed to come up with a table structure that works. What I'm trying to do is create a wish list feature which allows users to save a course to their profile for later. Originally, I created three fields in my 'users' table, named: 'saved_course1', 'saved_course2' and 'saved_course3'. I then tried to come up with a php/sql code that when a user clicks the wish list button on a courses page, the id of the course is saved to the one of the saved courses fields (providing that it isn't already filled), however someone pointed out to me that this would be an terrible way of doing this and it would mean my db wouldn't be normalised.
So to sum my problem up, I need help with creating a table structure that would allow users to save multiple course id's to their account, then allow me to get the id's of the courses and display them in a table on their profile page. Sorry if this makes no sense, as I'm finding it difficult to put it into words.
That's not so difficult just make this table structure below. Let me know if you don't understand it
Example
User(userid,name,etc)
Courses(coursesid,name,fee, etc)
WhishList(userid,coursesid)
userid is foreign key to User, null not allowed
coursesid is foreign key to Courses, null not allowed
Extract courses for particular user
select * from WhishList join courses on Whishlist.coursesid = Courses.coursesid where WhishList.userid = "USER_ID HERE";