> ## Documentation Index
> Fetch the complete documentation index at: https://docs.btsscorp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# SQL Validation

> Understand Koala's validation rules and fix common errors

## Validation rules

* **Read-only guard**: Only `SELECT` statements are allowed; DML/DDL is blocked.
* **Injection protection**: Patterns resembling unsafe concatenation or execution are rejected.
* **Bind variables**: Must use `:name` syntax; invalid placeholders are flagged.

## Common false positives

* Colons inside quoted strings (e.g., `'http://example.com:8080'`).
* Commented-out DML statements in multi-statement scripts.
* Bind variables inside complex string concatenations.

## Fixes

1. Ensure non-SELECT statements are removed or commented out.
2. Escape or move colons that are part of literal strings.
3. Keep bind variable names alphanumeric and consistent (`:startDate`).

<Tip>
  If validation blocks a legitimate query, simplify the statement and retry. Complex scripts are easier to validate when split across tabs.
</Tip>