So there are a few things with your code that aren't best practice or are a bit confusing.
prepared
statements with you SQL queries. They offer far better protection when using user derived data (it isn't clear whether your search parameters are from user input or from other code)$variables
in your double quoted strings it's good practice to use{curly braces}
to encompass them. It solves a variety of issues withPHP
using the correct variable and also makes it easier to read and maintain$Reg
has come from - so I have ignored it in the following codeAssuming that you have the following data in your table...
Table: results
StudentReg | school_session | Term | class | subjectID | Average
Sorted data returned by query
{-code-7}
I have adapted the code to useprepared
statements.
variables
Presumably these are declared somewhere further up your code...
{-code-9}
mysqli
{-code-10}
PDO
{-code-11}
Output
{-code-12}
If you are running MySQL 8.0, you can do the ranking directly in the database, using window functions:
select r.*, rank() over(order by average desc) rn
from results r
where
school_session = ?
and term = ?
and class = ?
and subjectid = ?
order by average desc
rank()
assigns the same number to ties.
Note that I changed the query to use parameters rather than concatenating php variables in the query string: this is both safer and more efficient.
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PHP (from the English Hypertext Preprocessor - hypertext preprocessor) is a scripting programming language for developing web applications. Supported by most hosting providers, it is one of the most popular tools for creating dynamic websites.
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DBMS is a database management system. It is designed to change, search, add and delete information in the database. There are many DBMSs designed for similar purposes with different features. One of the most popular is MySQL.
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