Chapter 9

This SQL query looks through the posts for instances of Vbulletin and replaces them with vBulletin. The WHERE clause is used to optimize the find and replace as this allows MySQL to take advantages of indexes, which speeds things up.

If you get an error running this query then check to see if you are using a table prefix in the database for the tables (such as vb_) and add this to the query. This would change the query to the following:

UPDATE vb_post SET pagetext = REPLACE (pagetext,'Vbulletin','vBulletin') WHERE pagetext LIKE '% Vbulletin%';

If you wanted to carry out a similar find and replace within PMs, you'd use the following query:

UPDATE pmtext SET message = REPLACE (message,'Vbulletin','vBulletin') WHERE message LIKE '%Vbulletin%';

By using MySQL queries you are taking total control over the data held in the database. We don't have the time or scope here to cover MySQL queries in detail, so for more information visit http://dev.mysql.com. Alternatively, you can read Mastering phpMyAdmin for Effective MySQL Management by Marc Delisle, published by Packt Publishing (ISBN 1-904811-03-5).

Programming Standards

Good programming is clear, unambiguous programming. Let's run through a few tips to help make your code more readable, easier to debug, and easier to make changes to later on.

Braces

For clarity each brace should be placed on its own line in the code:

if ($condition)

{

// code goes here

}

Don't be tempted to condense code like this:

if ($condition)

{// code goes here }

Indenting

Indent code between braces:

if ($condition)

{

// code goes here

}

Code between braces within braces should have deeper indenting:

if ($condition)

{

if ($condition2)

{

// code goes here

}

// some more code goes here

}

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Programmer's Reference

Give Operators Space

All operators (except -- and ++) should have a space either side.

$a = $b + $c;

String Quoting

All strings should be quoted with single quotes when they don't contain variables or control characters. Otherwise always use double quotes:

$a = 'Hello, World!'; $b = "Hello,\nWorld!"; $c = "$hello,\nWorld!";

Return Values

Use only lower-case true and false for return values. Upper-case should be reserved for custom constants.

if ($condition)

{

return true;

}

else

{

return false;

}

AND and OR

Always use AND rather than and or &&, and OR rather than or or || in your code.

if ($num1 AND $num2 OR $num3)

AS

Similarly, AS in foreach statements should be capitalized.

foreach ($array AS $num => $var)

{

// code goes here

}

SQL Queries

Under all circumstances, make sure that you double quote all SQL queries.

$DB_site->query("SELECT field FROM " . TABLE_PREFIX . "table ORDER BY field");

It may be better to write long queries on more than one line.

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Chapter 9

Naming Conventions for Functions

Custom names for functions you add should all adhere to the following naming conventions:

Prefix	Description
build_	Save data back to the database.
cache_	Read data from the database and create a temporary PHP cache variables to reduce
	SQL database load.
can_	Return true or false based on permissions.
construct_	Return variables containing HTML.
convert_	Convert the data format of input variables.
delete_	Delete data from the database.
exec_	Perform an action.
fetch_	Return arrays, strings, integers, etc.
file_	Deal directly with the file system.
handle_	Called by the bbcode parser to deal with a specific bbcode type.
import_	Take an array of data and import it into the database.
is_, contains_	Return true or false based on conditions.
js_	JavaScript functions defined within the PHP code.
log_	Append to the vBulletin logs.
parse_	Initialize the bbcode parsing process.
print_	Print code out to browser or buffer.
process_	Prepare an array for later reference.
sanitize_	Check and clear data (such as removing illegal characters) for later processing.
sort_	Sort data.
strip_	Strip elements from strings.
undelete_	Functions that undo a soft deletion.
vb_, vb	Replace built-in vBulletin PHP functions with replacements designed to increase
	functionality or alter the behavior of the built-in function.
verify_	Check conditions and generate an error message if particular conditions are satisfied.
xml_	Read or output XML.

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