database - MySQL Insert in table if it doesn't exist already ¿Am I doing it right? -

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While creating my application with the relational tables, I participated in the following problem:

I have The following table is for this example named "Valores": 

  ----------------------- | ID | Price | ----------------------- | 1 | Unique Valve | | 2 | Unique VAL2 | ----------------------- ID = etinininkment value = unique

What am I trying to do? Price if it is not already present, the way I am doing it now is: 

  Enter values ​​(id, value) values ​​(zero, "unique VAL2") Do;

So it will not do anything because price already exists. Now my question is:

¿What is the best and fastest way to do this is?

I think this is the best way for your scenario

For different purposes you can use the duplicate key on update or

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