Why is it not recommended to use "SELECT * FROM..." in SQL queries?

Using "SELECT * FROM..." in SQL queries is not recommended because it retrieves all columns from a table, including those that might not be needed. This can lead to unnecessary data transfer and performance issues, especially when dealing with large tables. It is better to explicitly specify the columns needed in the SELECT statement to improve query performance and reduce the amount of data being processed. 

// Specify the columns needed in the SELECT statement instead of using SELECT *
$query = "SELECT column1, column2, column3 FROM table_name WHERE condition";
$result = mysqli_query($connection, $query);

// Process the query result
if ($result) {
    while ($row = mysqli_fetch_assoc($result)) {
        // Do something with the retrieved data
    }
} else {
    echo "Error: " . mysqli_error($connection);
}

Keywords

SQL queries SELECT * performance security maintainability

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