How to store a array in a database?

问题

I am trying to learn php databases and I have a question. How do I store an array in a database? I saw an answer on stackoverflow and there were they doing something with type double and in an other answer they were talking about creating a table for every user but I can't find a solution.

So summarized. I want to store an array in a database. I have acces to phpmyadmin so from there can I set the value type. and I would like to store that array in one column.

Can somebody help me solving the problem?

edit one: The things I want to store are music tags. So in code it would be something like this:

 array('pop','rock','country');

I want to store It in one column to make it easy searchable

回答1:

Usually you shouldn't store arrays in a single column in a db. It is preferable to have a table with tags and another one that links your entity with its tags. So, before try to store an array in a table just think if it is really the right thing to do in your specific case (usually not).

If you are sure you want to do that then you have serialize and unserialize functions.

UPDATE (after five years) serialize and unserialize methods are inherently unsecure and should be avoided. It is preferable to store data in JSON format using json_encode and json_decode.

回答2:

Rather than storing arrays, try this:

Table 'genres' :

id | name
1  | pop
2  | rock

Table 'songs' :

id | ...
1

Table 'songs_genres' :

song_id | song_genre
1       | 1
1       | 2

And use JOIN's to get the genres for each song (or whatever)

回答3:

serialize() is one option here. You can serialize a PHP array into a string to store in the database, and when you return the string from the database you can unserialize() to convert it back from a string to an array.

[ Edit ]

After you've updated the question with an example of the data you plan to store, using a MANY:MANY relationship in the actual database structure is the correct way to go, as mentioned in @Alex M's answer

回答4:

You can use json_encode to make a json string from the array, like so :

    $jsonarray = json_encode($array);

then after retrieving the information you decode it.

    $array = json_decode($jsonarray, true); // the true will turn it into an array, 
    otherwise it's an object.

but I'd advice against it. try making a database which has the proper columns and store your data trough there.

回答5:

Every user can have one or more music tags. In later time they want to add or remove those tags. If you store all of their tags in one column you are pretty much left with string operation rather than database operation. create new table tbl_user_music_Tags and save each tag along with the user ID. this way you have full flexibility of adding, removing, updating and reading tags for a specific user.

回答6:

You can store it as an string such as 'rock, pop, foo, ...'. But if you want to manage tags, i think you should store tags in other table as @Alex M suggested.

来源：https://stackoverflow.com/questions/29562036/how-to-store-a-array-in-a-database

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php

mysql

arrays

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