> For the complete documentation index, see [llms.txt](https://muradkarakas.gitbook.io/sodium_documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://muradkarakas.gitbook.io/sodium_documentation/language-reference/built-in-triggers/pre_update-trigger.md).

# "pre\_update" Trigger

 Description

   `pre_update` trigger is fired just before a update sql command issued to the database. If function returns false, SQL command will not be issued.

**Declaration**

```
bool block_name.pre_update();
```

#### **Example**

```
bool categories.pre_update() {
        return false;
}
 
bool categories.pre_delete() {
        return false;
}
 
bool categories.pre_insert() {
        return false;
}
```

#### **See also**