What are the potential pitfalls of using multiple queries from the same table in PHP code?

Potential pitfalls of using multiple queries from the same table in PHP code include increased database load, slower performance, and potential for data inconsistency. One way to solve this issue is to combine multiple queries into a single query using JOIN or subqueries to retrieve all the required data at once. 

// Example of combining multiple queries into a single query using JOIN
$query = "SELECT t1.column1, t2.column2 
          FROM table1 t1 
          JOIN table2 t2 ON t1.id = t2.id 
          WHERE t1.condition = 'value'";

$result = mysqli_query($connection, $query);

if(mysqli_num_rows($result) > 0) {
    while($row = mysqli_fetch_assoc($result)) {
        // Process the data
    }
} else {
    echo "No results found.";
}

Keywords

SQL injection performance database locking duplicate data code readability

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