# SQL Server Rule: SML013
| | |
|----|----|
| Assembly | TSQLSmellSCA |
| Namespace | TSQLSmellSCA |
| Class | TSQLSmellSCA13 |
## Rule Information
| | |
|----|----|
| Id | SML013 |
| Friendly Name | CONCAT_NULL_YIELDS_NULL should be on |
| Category | CodeSmells |
| Ignorable | false |
| Applicable Types | Model |
## Description
CONCAT_NULL_YIELDS_NULL should be on
### Examples
```sql
CREATE PROCEDURE dbo.Sets
AS
SET ANSI_NULLS OFF
SET ANSI_PADDING OFF
SET ANSI_WARNINGS OFF
SET ARITHABORT OFF
SET NUMERIC_ROUNDABORT ON
SET QUOTED_IDENTIFIER OFF
SET CONCAT_NULL_YIELDS_NULL OFF
-- SML013, SML014, SML015, SML016, SML017, SML018, SML019, SML030
```
<sub><sup>Generated by a tool</sup></sub>
