SA0160 : Deprecated use of @, @@, or names that begin with @@ as Transact-SQL identifiers

Introduction

Identifiers that start with @ or @@ in T-SQL can lead to confusion and errors in code interpretation.

Description

In T-SQL code, @ is commonly used for declaring and referencing local variables, while @@ is used for system functions (or global variables like @@SERVERNAME ). Misusing these conventions by naming tables, columns, or user-defined variables in a similar manner can cause conflicts or unexpected behavior, as these symbols have predefined meanings.

For example:

-- Example of problematic use of identifiers
SELECT @@someGlobalVar FROM MyTable;
CREATE TABLE @myTable (ID INT);

In the first example, using @@ suggests a system function, which can be misleading if not correctly defined. In the second example, using @myTable can cause confusion, as it mimics local variable syntax, leading to potential misinterpretation within scripts or stored procedures.

Creates ambiguity in distinguishing between system functions and user-defined identifiers.
Increases risk of syntax errors or logical errors in queries and stored procedures.
Can lead to maintenance challenges and lower code readability.

How to fix

Avoid using identifiers that start with @ or @@ to prevent confusion and errors in T-SQL code interpretation.

Follow these steps to address the issue:

1.Review the reported identifier and understand its current usage within your database scripts or code.

2.Rename the identifier to a more descriptive and unique name that does not begin with @ or @@ . This will ensure it is not mistaken for a local or system-defined variable.

3.Update all references to the renamed identifier within your database objects, such as tables, stored procedures, and functions, to ensure consistency and prevent errors.

For example:

-- Example of corrected query
CREATE TABLE MyTable (ID INT);
SELECT someGlobalVar FROM MyTable;

Scope

The rule has a Batch scope and is applied only on the SQL script.

Parameters

Rule has no parameters.

Remarks

The rule does not need Analysis Context or SQL Connection.

Effort To Fix

3 minutes per issue.

Additional Information

Deprecated Database Engine Features

Discontinued Database Engine Functionality

Example Test SQL

declare @ as int, @@ as int, @@a bit ,@@b int

Analysis Results

	Message	Line	Column
1	SA0160 : Deprecated use of @, @@, or names that begin with @@ as Transact-SQL identifiers.	1	8
2	SA0160 : Deprecated use of @, @@, or names that begin with @@ as Transact-SQL identifiers.	1	18

Analysis Rules