Missing records in a database can be a frustrating and time-consuming issue for any organization. It can lead to inaccurate data and hinder decision-making processes. In this article, we will discuss how to find missing records in one table compared to another using HTML tags formatting.
First, let's understand the scenario. Suppose you have two tables, A and B, with the same set of records. However, table A has some additional records that are missing in table B. Now, your task is to identify these missing records and take necessary actions.
To begin with, let's create a simple HTML table to represent our database. We will use the <table> tag to create a table and the <tr> and <td> tags to define rows and columns, respectively.
<table>
<tr>
<td>Table A</td>
<td>Table B</td>
</tr>
<tr>
<td>Record 1</td>
<td>Record 1</td>
</tr>
<tr>
<td>Record 2</td>
<td>Record 2</td>
</tr>
<tr>
<td>Record 3</td>
<td>Record 4</td>
</tr>
<tr>
<td>Record 4</td>
<td>Record 5</td>
</tr>
</table>
As you can see, table A has four records, while table B has five records. Our task is to identify "Record 3" and "Record 4" as the missing records in table B.
To achieve this, we will use the <style> tag to add some CSS styling to our HTML table. We will give a different background color to the cells in table B that do not match with the cells in table A. This will make it easier for us to identify the missing records.
<style>
table {
border-collapse: collapse;
}
td {
border: 1px solid black;
padding: 5px;
}
.missing {
background-color: yellow;
}
</style>
Now, let's add the "missing" class to the cells in table B that do not match with the cells in table A. We will use the <script> tag to achieve this.
<script>
// Get all the cells in table A
var cellsA = document.querySelectorAll('table tr:nth-child(n+2) td:nth-child(1)');
// Get all the cells in table B
var cellsB = document.querySelectorAll('table tr:nth-child(n+2) td:nth-child(2)');
// Loop through the cells in table B
for(var i = 0; i < cellsB.length; i++) {
// Check if the cell in table B does not match with the cell in table A
if(cellsB[i].innerText !== cellsA[i].innerText) {
// Add the "missing" class to the cell in table B
cellsB[i].classList.add('missing');
}
}
</script>
Now, when we refresh our HTML page, we can see that the cells with "Record 3" and "Record 4" in table B have a yellow background, indicating that they are missing records.
