# Line Charts from SQL Data
Line charts are used to display trends and changes over time.
In this tutorial, the number of security events per day will be displayed using a line chart.
---
## Step 1 - Create the SQL Query
The following query counts the number of events recorded each day.
```sql
SELECT
DATE(event_timestamp) AS event_date,
COUNT(*) AS total
FROM cyber_security_events
GROUP BY DATE(event_timestamp)
ORDER BY event_date;
```
Example result:
| event_date | total |
|------------|------:|
| 2026-06-01 | 12 |
| 2026-06-02 | 18 |
| 2026-06-03 | 9 |
| 2026-06-04 | 15 |
---
## Step 2 - Retrieve the Data with PHP
```php
query($sql);
$data = [];
while($row = $result->fetch())
{
$data[] = [
$row['event_date'],
(int)$row['total']
];
}
?>
```
---
## Step 3 - Create the Chart Container
```html
```
---
## Step 4 - Create the Line Chart
```html
```
[](https://mr.napper.au/uploads/images/gallery/2026-06/image-1782086063395.png)
---
## Understanding the Chart
The horizontal axis displays:
```text
Date
```
The vertical axis displays:
```text
Number of Security Events
```
This makes it easier to identify:
- Busy periods
- Trends over time
- Sudden increases in activity
- Patterns in the data
---
## Complete Example
```php
query($sql);
$data = [];
while($row = $result->fetch())
{
$data[] = [
$row['event_date'],
(int)$row['total']
];
}
?>
```