PHP/SQL tutorial

For this you will need:
PHP 5.1+
mySQL
A server, Or localhost.
Ok, lets get started. (spoilers are just acting as tabs.)
First, lets get the sql connection up and running:

connect.php file:

Show Hide

PHP Code:

---

<?php
$con=mysql_connect(servername,username,password);
if (!$con){
  die ('Could not connect: '.mysql_error());
} else {
// code for connected.
}
?>

---

Now, we will do a basic database create.
Code:

Show Hide

PHP Code:

---

<?php
include ('connect.php');//the file we made above
$dbname="name of database";
if (mysql_query("CREATE DATABASE ".$dbname.",$con)){
    echo "Database created";
} else {
    echo "Error creating database: " . mysql_error();
}

mysql_close($con);// to close the database
?>

---

this is how to insert:
Code:

Show Hide

PHP Code:

---

<?php
include ('connect.php');
$dbname="name of database";
$table="table to insert";
mysql_select_db($dbname, $con);

mysql_query("INSERT INTO ".$table." (row1, row2, row3)
VALUES ('value1', 'value2', 'value3')");

//close connection
mysql_close($con);
?>

---

How to create a table:
Code:

Show Hide

PHP Code:

---

<?php
include ('connect.php');
$dbname="name of database";
$table="table to make";
mysql_select_db($dbname, $con);
$sql="CREATE TABLE ".$table.
"(
personID int NOT NULL AUTO_INCREMENT, // make the "personID" row auto increase.
PRIMARY KEY(personID), // part of the auto increasing.
row1 varchar(15),//the number "15" is the max length of the value's that can be inserted
row2 varchar(15),
row3 int // int is number onaly
)";
// Execute query
mysql_query($sql,$con);
//close connection
mysql_close($con);
?>

---

How to delete:
Code:

Show Hide

PHP Code:

---

include ('connect.php');
$dbname="name of database";
$table="table to make";
mysql_select_db($dbname, $con);

mysql_query("DELETE FROM ".$table." WHERE ".$row."='".$value."'");

//close connection
mysql_close($con); 


---

How to read:
Code:

Show Hide

PHP Code:

---

include ('connect.php');
$dbname="name of database";
$table="table to make";
mysql_select_db($dbname, $con);
$result = mysql_query("SELECT * FROM Persons
WHERE FirstName='Peter'");

$row1="a row to put out, e.g. name";
$row2="a row to put out, e.g. email";

while($row = mysql_fetch_array($result)){
  echo $row[$row1] . " " . $row[$row2];
  echo "<br />";
}

//close connection
mysql_close($con); 


---

This isn't a tutorial, it doesn't explain the code. It's more of a collection of code snippets, just like your other 'tutorial'.

how about you read whats called a "comment" or the // bits in the code.. ide say that explains my code tyvvm.

Quote:

---

Originally Posted by badboyxlr

how about you read whats called a "comment" or the // bits in the code.. ide say that explains my code tyvvm.

---

Ok, I'll read the comment in the first code snippet. What? It just says 'code for connected'? I'm reading this tutorial because I'm a beginner to PHP, how am I supposed to know what those functions do and why you're checking if $con is true?

Second snippet. Oh look, only one comment and all it tells me is that we've just made connect.php. It doesn't tell me what the include() function does, or any of the other code there.

Third snippet. Only one comment in there, but it is a tiny, tiny bit helpful. Has the same problem as the first two.

Fourth snippet. Ok, you've explained a tiny, tiny, tiny bit of the SQL, but it isn't helpful. Has the same problem as the others.

Fifth snippet. Same problems.

Sixth snippet. Same problems.

tyvvm gg

This isn't a tutorial. This is posting code snippets as Trinity said. You're not explaining the WHERE syntax, or anything to do with anything. You're just posting code snippets to do certain things.

And usually it's the same file over and over.. this shouldn't be labeled as a tutorial, as it's not. A bad one at that.

Also, when you make a connection file, you usually dont need to tell the script that includes the connect file to use that mysql connection again, it knows!

When using " . $blah . ", you dont need to close it if you're not doing anything more to be outputting into the query, so its either "Hello {$name}" or "Hello " . $name; or "Hello " . $name . "";

The way you have coded is in my opinion, bad practice, learn to code badly, expect to keep coding badly.

For example, Im self taught in PHP, HTML, CSS, therefore my coding may not be as good, nor my knowledge be as good as someone whos been educated in it...

Use the connect files to define everything to do with the connection...

Lew.

i am also self taught, and the way you have put that i dont know what your getting at, i have put it like this so that each item of the script is apart, so they dont have to have 1 huge script were if they want to insert they get a load of errors.

---------- Post added 22-03-2011 at 08:56 PM ----------

yes i agree, but i put tutorial. Shame i cant edit it.. and do you always be so rude on posts, i am providing people with free snippets to copy and past, and all you do is criticize it?

Quote:

---

Originally Posted by badboyxlr

i am also self taught, and the way you have put that i dont know what your getting at, i have put it like this so that each item of the script is apart, so they dont have to have 1 huge script were if they want to insert they get a load of errors.

---------- Post added 22-03-2011 at 08:56 PM ----------

yes i agree, but i put tutorial. Shame i cant edit it.. and do you always be so rude on posts, i am providing people with free snippets to copy and past, and all you do is criticize it?

---

I'm pretty sure we're all self taught here, it's no reason for us to use bad practices.

You're the only person that's been rude in this thread, we're just being honest so that people reading the thread understand that this isn't the way to do things, then they'll learn from other places and become PHP gods.
You can learn a lot on this forum too if you lose the attitude.

One of my favorite PHP lines is

PHP Code:

---

<?=(($this=$that) ? 'This &amp; That' : 'That &amp; This')?>

---

You'll soon learn how to deal with "errors" in php ;)

Lew.

or, you could do it the easy way.. if (!$string){code for error}