Merging Cells in a Column SQL/PHP

Introduction

In this article, we will explore how to merge cells in a column using SQL and PHP. We will provide an example of a database table with multiple rows and columns, and demonstrate how to modify the code to merge cells in specific columns.

Understanding the Problem

The problem presented is as follows:

• We have a database table grafik with columns date, shift, stanowisko_1, a_1, a_2, a_3, a_4, stanowisko_2, and b_1, b_2, b_3, b_4.
• The table has multiple rows, each representing a different entry.
• We want to modify the HTML code to merge cells in specific columns, such as date and shift.

SQL Solution

To solve this problem, we can use the rowspan attribute in our SQL query. However, since we are using PHP to generate the HTML table, we cannot directly use rowspan in our SQL query.

Instead, we will use a combination of PHP and JavaScript to achieve the desired effect.

PHP Solution

We can modify the PHP code to add a new column with merged cells using the rowspan attribute. Here is an example:

<?php
$polaczenie = @new mysqli($host, $db_user, $db_password, $db_name);
$wynik = mysqli_query($polaczenie,'SELECT * FROM grafik');

echo "<table cellpadding=7 border=3>";
echo "<tr>";
for ($i = 0; $i < count($wynik->fetch_row()); $i++) {
    if ($i == 0) {
        echo "<td colspan='11'>" . $wynik->fetch_row()[0] . "</td>";
    } else {
        echo "<td>" . $wynik->fetch_row()[$i - 1] . "</td>";
    }
}
echo "</tr>";

while ($row = mysqli_fetch_assoc($wynik)) {
    if ($row['date'] == $wynik->fetch_row()[0]) {
        echo "<td colspan='11'>" . $row['shift'] . "</td>";
    } else {
        echo "<tr>";
        echo "<td>" . $row['date'] . "</td>";
        echo "<td>" . $row['shift'] . "</td>";
        echo "<td>" . $row['stanowisko_1'] . "</td>";
        echo "<td>" . $row['a_1'] . "</td>";
        echo "<td>" . $row['a_2'] . "</td>";
        echo "<td>" . $row['a_3'] . "</td>";
        echo "<td>" . $row['a_4'] . "</td>";
        echo "<td>" . $row['stanowisko_2'] . "</td>";
        echo "<td>" . $row['b_1'] . "</td>";
        echo "<td>" . $row['b_2'] . "</td>";
        echo "<td>" . $row['b_3'] . "</td>";
        echo "<td>" . $row['b_4'] . "</td>";
    }
}
echo "</tr>";
?>

JavaScript Solution

Alternatively, we can use JavaScript to merge cells in the table. We will add a new div element with the rowspan attribute and then modify the existing code to insert the merged cells.

Here is an example of how you could implement this:

// Get all rows in the table
var rows = document.getElementsByTagName('tr');

// Loop through each row
for (var i = 0; i < rows.length; i++) {
    // Check if the row has a cell with rowspan attribute
    var rowspanCells = rows[i].getElementsByTagName('td');
    for (var j = 0; j < rowspanCells.length; j++) {
        if (rowspanCells[j].getAttribute('rowspan') != '') {
            // Insert the merged cells
            var newDiv = document.createElement('div');
            newDiv.setAttribute('rowspan', rowspanCells[j].getAttribute('rowspan'));
            rows[i].insertBefore(newDiv, rowspanCells[j]);
            break;
        }
    }
}

This JavaScript code will insert a new div element with the rowspan attribute and then modify the existing cells to use it. However, this approach requires manual modification of the HTML table.

Conclusion

In conclusion, we have explored different ways to merge cells in a column using SQL and PHP. The best solution depends on your specific requirements and the tools you are using.

If you need more control over the HTML structure, you can use JavaScript to modify the existing code.

However, if you want to maintain consistency with the rest of your codebase and avoid manual modifications, using rowspan in your SQL query is a good option.

Last modified on 2025-01-31