WEBVTT

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In this video we get to learn how to retrieve data from a database.

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So first of all we're going to need to connect to our database so we're going to be using the same code

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we used earlier to connect to a database so you can just copy from the previous file.

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OK.

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And then we are going to write some code to retrieve data from a table.

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OK.

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So let's have a look at our table in the place might add me.

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So in order to get all the rows of the table just like this we have run this query.

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And if you read the query says select start from users where 1.

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OK.

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And that's the equivalent of select stuff from users.

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OK.

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Because one is true.

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OK.

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And then we use a key word limit starting with 0 and then Terzi So 0 is the row where we're going to

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start.

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And 30 is the number of rows that you would like to show.

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So this means that we're going to show so as heroes starting from record 0.

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OK.

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OK so now we are going to create a query that we're going to store in a variable as curial.

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So these queries just going to select all the rows of our table.

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So we're going to write selects staw from us.

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OK.

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You can.

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Right where one but it does the equivalent of this anyway.

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So now we are going to execute our query.

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Okay.

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And the results of the execution function are going to be stored in a variable.

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But we're going to call results.

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OK.

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So inciter is also going to store the outputs of the function my school-I query.

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And if you remember this function will take a couple of parameters so the first one is the connection

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variable and the second parameter is the query again.

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So to check if this is successful we are going to place this inside the if condition.

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OK.

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And we're going to write if results equals this then we're going to execute some code.

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OK.

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And to start we are just going to print these results very well using the prince and his function.

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OK.

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And if we save and try lots we get here an objects which means that this has been successful and we

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have saw the results of this function inside the results variable and the result.

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We know that if it's successful it's an object.

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OK.

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All right so now how do we get the table rose.

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OK so first of all we are going to check the number of rows corresponding to our results.

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To do that

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we're going to use the function my as Kulai

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underscore number call rows.

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OK.

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And it's going to take as a barometer the results variable.

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OK.

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So let's just echo this.

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Now I can see that you got five rows and I see exactly the number of rows in our table.

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OK.

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So what are we going to do.

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We are going to check if the number of rows is greater than zero.

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OK then we are going to execute some other code.

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All right

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now we are going to cycle through all the arrows of our results.

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OK.

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Using another function that we call my school-I fetch array.

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So this function is going to take as a barometer our results sets.

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So in our case it's going to be our results very well.

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Okay.

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And every time we call this function it is going to fetch the next row.

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Okay.

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And then he's going to return an array of strings corresponding to that throw.

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So if we call it the first time it's going to go to row number one.

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Fetch it and then he's going to return and the array corresponding to that row and the array could be

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associated numeric or both.

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And then when we call it the second time it's going to go to the second row return an array and so on

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until we have no more rows in the result sets and in that case it is going to return not.

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OK.

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So let's try to call this function several times.

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So in our case we of course a table of five rows in our result sets should have five rows in it.

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So let's call our function six times.

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So the five first timers we're expecting the function to return an array of strings.

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But the six thousand six time we are expecting the function to return.

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No.

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OK so let's call the function

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six times so let's give its results viable as an argument.

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OK and let's bring the results using DePrince underscore our function.

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Okay.

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Just before that let's echo a paragraph saying Call number 1

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K

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and is capitis several times.

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That's going to be called them 2 3 4 6 4 3 5 and 6.

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Ok so if we save and refresh.

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Okay.

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So you can see that call number 1 gave us an array.

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Okay.

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So just one thing before we look at the AS which row we are looking at you can see here those for the

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same value we have two elements.

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Okay.

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And then we have the same thing same value twice.

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So that first the first one corresponds to the numeric key and then the second one corresponds to an

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agitated key.

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Okay.

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So we are having here a combination of switches and numeric array but if we want to have only associative

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array then we can add another barometer to our my is Karoli fate array function.

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Okay.

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And that parameter is going to be my school-I my Escurial I underscore associative.

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OK all in capital letters just like these.

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So if we save that and refresh our page then we are getting a raise.

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OK if we want numeric arrays then we just replace does by numeric.

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And this is what we get.

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OK so for now let's stick to arrays and let's do that for all the the arrays

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.

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OK so you're getting only CJC varies.

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So if we look at the first results is corresponds to the first record on our table or the first row

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of our result sets.

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Can we can check that.

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We've got Peter.

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OK.

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And the second one also Peter Thaila and then the third one you call Mark Zuckerberg and so on.

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So once we arrived to call number six.

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So we don't see anything on our screen.

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Okay.

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And that's because this value here is no.

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And we can check that by guessing the type of these of these value are these variable or whatever the

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function is returning here by saying get type Okay.

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Are going to place us in the arguments.

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Okay so now if we save and refresh we can see that the loss was because of the function is choli fetch

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array is not.

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Okay.

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All right.

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So we're going to use this to cycle through our results sets.

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Okay.

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And preens all the rows okay inside our result sets.

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So rather than them printing this many times okay we're going to use a while loop and the condition

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of our while loop is going to be the outputs of this function.

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Okay.

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So they just copy this for now.

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And it just delete all this and then we're going to have a one loop.

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So the condition is going to be this.

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Okay.

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Well the because of our feature a function