SQL and PHP database access

Question

I'm very new to PHP, SQL I've worked with using Coldfusion but only with very simple queries. In coldfusion to access a specific database

<cfquery dbname="blah">

I know in PHP I have to use mysql_query() and mysql_connect(), and here is the code I have, so I understand how to access a server and a table, but not the database. How can this be done?

<?php
$sql_branch = "SELECT BranchNum
              FROM Branch WHERE
              branchName = '$_POST[branch]'";
$connect = mysql_connect('students','xxxxxxx','xxxxxxx');
if(mysql_query($sql_branch, $connect)) {
  $branch = mysql_query($sql_branch, $connect);
}
else {
  echo "error".mysql_error();
}
$sql_result = "USE henrybooks;
              SELECT AuthorFirst, AuthorLast, OnHand, Title
              FROM Inventory i, Wrote w, Author a, Book b
              WHERE i.BookCode = b.BookCode AND
              i.BookCode = w.BookCode AND a.AuthorNum =
              w.AuthorNum AND i.BranchNum = $branch";
if(mysql_query($sql_result, $connect)) {
  $result = mysql_query($sql_result, $connect);
}
else {
  echo "Error".mysql_error();
}

Also I'm unsure if my Error checking is right, my professor did not really explain how that works exactly.

Thanks!

Answer 1

Find out the database name and select it before making any queries:

$connect = mysql_connect('students','xxxxxxx','xxxxxxx');
mysql_select_db('dbName', $connect);

Documentation for mysql_select_db.

Answer 2

Use mysql_select_db to connect to the database. Most of the mysql_ functions should be what you are looking for when working with mysql databases.

Answer 3

You probably want to use mysql_select_db:

$connect = mysql_connect('students','xxxxxxx','xxxxxxx');
mysql_select_db( "blah", $connect );

Answer 4

Are you looking for mysql_select_db?

You can find all mysql functions here.