基于另一个表的动态表插入记录mysql

Question

I want to create a posting system to a profile. I created a database for storing all users posts each user have a table.

Ihad created another database for storing the comments of each posts. My logic is to create each table in the comments database and store each comment in that.

Is there a logic to link the post and the comments. I thought to use mysql last insert id but it will return last id which will create error because one of the post will not have a table.

Is there any other way?

Answer 1

Another way would be to have a single table for posts, and identify a user post in the table using a userid column. To find all posts by a particular user, simply query by the user's ID. By doing so, you have a single table to manage, and you can do a lookup easily. If you create separate tables for each user, you have to create additional logic to first figure out which table to use. If a user is removed, you delete a table, rather than simply removing some rows from a common table.

The same logic applies to the comments table - add columns for postid', commentid , userid`. Again, a single table contains all the comments. To find comments on a particular post, you would do a simple query such as

  select comment_text
  from   comments_table
  where  postid = ?

The whole purpose of using MySQL is to leverage relationships between entities, ie a user owns posts , a post is linked to comments .

If you do not want to use a relational schema like this, take a look at NoSQL DBs.

Answer 2

You have a couple options here:

• Add a user_id column to your posts table, and a post_id, and user_id column to your comments table. You can then setup foreign keys with one-to-many relationships.

• Only use a single table that has (in addition to your existing) a user_id, and type column. Type will define comment/post/etc. This can be defined with intermediary tables as a number mapped to a CONST, string, or any other way that you see fit (intermediary best option imho).

• Vary the above example and use 2 intermediary tables to match users to posts and comments to posts (possibly also users to comments).