# Writing PL/PgSQL Scripts

## PL/PgSQL Code in the Script Engine

In *Eliona*, scripts can be written not only in Python but also in **PL/PgSQL**. This allows for the direct processing of SQL queries within the script engine.

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## Script Definition

When you create a new **PL/PgSQL** script in the script engine, a template function is automatically suggested. This template serves as a starting point for script creation.

```sql
DO $$
DECLARE
    -- Variables can be declared here
BEGIN
    -- SQL queries and operations can be executed here
END $$;
```

## Example: Update Timestamp

The following example shows how a script retrieves the current timestamp (`NOW()`) from the database and updates it for a specific asset (`asset_id = 1`) in the `heap` table:

```sql
DO $$
    DECLARE r timestamptz;
BEGIN
    SELECT NOW() INTO r;
    UPDATE heap SET ts = r WHERE asset_id = 1;
END$$;
```

▷ *The script saves the current timestamp in the `heap` table for the asset with the ID `1`*

{% hint style="warning" %}
Note on security: Direct database changes are effective immediately and cannot be undone.
{% endhint %}