Dynamic sql search in php - php

Question

Trying to create a dynamic search functionality.
Goal : allowing user to search by email (if not empty), if empty (by last name), if both are not empty, than by both, etc.
I know I can write if statement depicting every scenario and than insert SQL command based on that, question is can this be handled in a more simplified manner. Thanks for your help.
Current function set up does OR across all fields, values are coming from $_POST:
find_transaction($email,$last_name,$first_name, $transaction_id)
{
GLOBAL $connection;
$query = "SELECT * ";
$query .= "FROM transactions WHERE ";
$query .= "email='{$email}' ";
$query .= "OR last_name='{$last_name}' ";
$query .= "OR first_name='{$first_name}' ";
$query .= "OR transaction_id='{$transaction_id}' ";
$query .= "ORDER BY date DESC";
$email = mysqli_query($connection,$query);
confirm_query($email);
return $email;
}

Answer 1

I do this all the time, it's not too much work. Basically build your WHERE statement dynamically based off your POST variables, using a series of if statements.
For example:
$where_statement = "";
// First variable so is simpler check.
if($email != ""){
$where_statement = "WHERE email = '{$email}'";
}
// Remaining variables also check if '$where_statement' has anything in it yet.
if($last_name != ""){
if($where_statement == ""){
$where_statement = "WHERE last_name = '{$last_name}'";
}else{
$where_statement .= " OR last_name = '{$last_name}'";
}
}
// Repeat previous 'last_name' check for each remain variable.
SQL statement would change to:
$query = "SELECT * FROM transactions
$where_statement
ORDER BY date DESC";
Now, the SQL will only contain filters depending on what values are present, so someone puts in just email, it would generate:
$query = "SELECT * FROM transactions
WHERE email = 'smith#email.com'
ORDER BY date DESC";
If they put in just last name, it would generate:
$query = "SELECT * FROM transactions
WHERE last_name = 'Smith'
ORDER BY date DESC";
If they put both, would generate:
$query = "SELECT * FROM transactions
WHERE email = 'email#email.com' OR last_name = 'Smith'
ORDER BY date DESC";
Etc., etc.
You could add as many variables you wish here, and basically if the specific variable is not blank, it will add it to the "$where_statement", and depending on if there is anything in the "$where_statement" yet or not, it will decide to start with = "WHERE ", or append .= " OR" (notice the '.=' and the space before 'OR'.

Answer 2

Better use Data Interactive table : http://datatables.net/
It's useful and no SQL-injection :) Good luck !