5.8 Tags Foreign Keys

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I welcome back to Muzzle five sequel development. This is lesson to Thorne Keys

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and we're moving into sub lesson 2.4 tags. And for the tags table, we're actually gonna have to create a pivot table. And the reason we need to great a pivot table is because tags between articles is gonna have a many too many relationship. And

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what I mean is that an article

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you can have many tags

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and a tag

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come belong to many articles.

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So if something gets tagged important,

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you know, you could have mark multiple articles tagged important. And then you could also have Maur tags in just that one tag

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on the article as well.

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So with that said, Let's get started,

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We're going to Ah, right, Click on tables, Select Create New Table

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and we're going to give it a name of article

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underscore tags.

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We're gonna add a new column. We're gonna start with the usual I D column.

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We're going to make that a big end unsigned. It's not allowed to be No.

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And for this we're just gonna add the columns that we need,

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which will be the article on the score i G. So that we can

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and became which article it belongs to.

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It's not allowed to be no,

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and we need to create another new column

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called Tag on a Score i d.

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Same thing Big Anton signed.

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It's not allowed to be No,

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just looked. Okay,

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let's go ahead and save what we have.

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Persist.

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Let's add in our primary key constraint.

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I'm going and save that.

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Let's head back over to the columns and turn on the auto increment

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or assist.

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And after this finishes, let's go ahead and add in the necessary foreign keys.

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So we're gonna right click great new foreign key.

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Let's go ahead and performing against the articles table first, so we need to select the article I d

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against the reference to column I D. Which is on the articles table.

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We'll select Okay,

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we need to add one more foreign key,

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and this time we're gonna do the tags table

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and the

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column will be the tag i d.

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The Russians column will be the idea on the tag stable,

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and let's go ahead and save that.

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It shouldn't take too long.

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It seems to be taking it a little bit longer than usual.

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what should be done pretty soon.

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Okay, we're back. I don't know why it took it a little bit of time to perform that action. It took about a full minute to do that, but it finished.

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And I bet you it looks like it already updated the E R diagram without doing a refresh, which is interesting. Usually you have to refresh or even close the application.

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So within the E R diagram, we could see that the article tags table we just created sits in between the tag stable and the articles table. When a programmer or an application wants to add a tag to an article, it will first ensure that Thea tag that it's trying to add it exist.

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Then it will ensure the article exists. And then it will add that as a record to the article tags table,

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and that will help protect our data and integrity by assuring the tag exists and the article exists.