WEBVTT

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Code does count for example and if we save and refresh now we see an error message four line as you

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want.

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So we didn't manage to connect to the database.

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That's why we see this error message.

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And then we can see that's our link variable is a boolean false.

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And then you can see the output of our die function.

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Ok so

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since the function my school-I connects returns false when we don't manage to connect.

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We can change the structure of our code and rather than doing the check off so we sets the link variable

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we can attempt connection and then use the keyword all OK and then write the dice statements right after

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.

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OK so we don't need this check anymore.

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So let's try this.

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So if you're to press the page OK so we can still see the error message for the connection but now we

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can see the output of our die function but we don't want to see this anymore because if you don't manage

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to K'NEX we just want to show this message.

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So there is a trick we can use for that is going to be by adding up.

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Just before my girl I connect.

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OK.

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Now if you refresh we can see that we see only the outputs of the dight function.

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Ok so we can use the this symbol actually when we are setting a certain variable to an expression.

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OK.

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And it's a good trick to avoid getting the generated APHC error.

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So now let's try with the Carex details and see what happens when we connect to the database and we

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can see our success.

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Mr. message that.

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OK.

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All right so that's how we can connect to a database and check connection using Escurial I am using

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the procedural way.

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Now let's try the object oriented way.

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OK so

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let's comment this and writes another piece of code.

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So now to connect to the database we are going to set our link variable z and objects and this time

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we're going to use a constructor.

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So you can use the keyword new and then my Escurial like constructor.

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So the constructor is going to take exactly the same parameters we have used earlier.

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So the host username password and database names you can just copy those.

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All right.

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And the difference now is is going to be the link variable is going to be in objects all the time.

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So even if we fail to connect to the database.

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OK the link variable is going to be an object unlike the procedural way where the link variable could

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be a boolean false when we did not manage to connect.

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OK.

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All right so now let's check the connection

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which is other common so that connects and thus checking connection.

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All right so now to check the connection we can check

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a condition.

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OK.

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I'm going to use a property of the link objects so this property is connects

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underscore Erin.

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OK.

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So you want to make sure.

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So we're going to check if this one is greater than zero which means that you cause an error.

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OK.

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And then if that's correct.

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That's true.

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We are going to use the function die and we're just going to Auschwitz and animates it.

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OK.

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So we're going to say unable to connect and then call on and then we're going to add the error string

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.

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And this time it's going to be a property of our objects.

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OK.

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So in the procedural way we used a schoolboy connect error function and this time we are going to use

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the property connect error.

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Ok I know it's going to return a string describing the loss K'NEX era.

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All right.

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So let's use that going to this drink.

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So we're going to the link objects and we're accessing the property connect area.

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OK.

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And then right at the end we're going to echo our success paragraph.

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Okay.

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And if we save and refresh so you can see that we are connected successfully to the database because

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all details are correct.

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If we change anything there that if refresh fresh.

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Now we can see an error message.

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OK corresponding to line 39 where we trying to connect and then we can see the outputs of our die function

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.

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OK well clearly it changes back to those come and have our success message.

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OK.

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So in the next video we can learn how to connect to the server and create a database in the server