Table of Contents
SQL Standards
Special care must be taken for Cacti to properly support multiple DBMS's.
Quotes
When writing queries do not use quotes around numeric values. While MySQL is not strict about types, most DBMS's assume that any value contained within quotes is a string.
As well, single quotes are used unless a variable is referenced
$graphs = db_fetch_assoc('SELECT * FROM graph WHERE height >= 150');
$rows = db_fetch_cell("SELECT count(*) FROM $archive_table");
SQL Functions
Do not use functions in SQL queries that are provided by the DBMS. These functions are generally not uniformly support or even available in all DBMS's. Common examples of such functions are MD5(), CONCAT(), and NOW().
Database Abstraction
Always use the database libraries provided by Cacti as an extra layer between the code and ADODB. Details about these functions are located in lib/sys/database.php.
