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In this video, we're going to talk about renaming tables and also renaming columns.

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If you want to rename a table.

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We have two choices.

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We can do a simple command, a simple statement, which is rename table and then the current name,

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and then to the new name.

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Or I also can do the same thing but put alter table in front of it.

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Either one works, but this is shorter, so rename table.

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Let's try an example.

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We have let's see, show tables.

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We have companies.

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Let's rename companies to be suppliers to start.

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So select start from companies.

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I want to rename table that's called companies to suppliers.

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And now if I try and select start from companies, it doesn't exist.

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But if I select star from employers or what am I doing suppliers, we see the same table.

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It just had a new name, so now it's called suppliers and I could rename it back using the alter table

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syntax.

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So this is the other way of renaming a table.

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We use alter table, This is the alter table docs and then we do the table name and then rename to the

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new table name.

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So if you prefer this syntax alter table and then suppliers rename to and then what do I want to rename

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it to?

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Let's go back to companies.

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And now if I do show tables, we have a company's table.

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If I select star from suppliers doesn't exist.

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Select star from companies though.

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There we are.

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We see the same table as before.

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So two different ways of renaming a table.

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But now I want to talk about renaming columns.

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So when we want to rename a column, we use Alter table the table we're trying to alter and then rename

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column what the current name is and then what we want to change it to.

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Like the if it's called name, we'll rename it as biz name.

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So I'll show an example of this.

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What do we have that we could rename?

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How about in our company's table?

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We have name, let's call it company name.

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So I want to rename this column.

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Right.

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If I do select star from companies just one more time.

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Here we see it's called name or describe companies.

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We see the column name.

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So let's rename that.

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Let's do a alter table, the table name that we're altering, and then what we're trying to do, rename

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column and this is important in this example, rename column column is required.

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It's not optional.

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Whereas with ADD column as we saw, that was optional Drop column column is optional, but with rename

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column is required.

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So that's another reason I like to use column always.

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It's just be consistent.

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Then you don't have to remember when you can use it and when you can't or when it's optional.

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Okay, so rename column old column name to the new column name.

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So rename column and it's called name right now to company name.

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All right, let's run that here.

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It's called name, as we see.

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I rename it if I describe companies now, it is called Company name.

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If I select start from companies, we see company name.

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So that's how we can rename a column.

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Next.

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What about if we wanted to change the data type or constraints or something on that column?