SA0256 : A cursor with the same name is declared earlier. Avoid reusing cursor names

When writing T-SQL code in SQL Server, it is crucial to declare each cursor name only once in the current scope. Re-declaring a cursor can lead to unintentional behavior, logical errors, and difficulties in managing and maintaining code.

For example:

1-- Example of problematic cursor declaration
2DECLARE cursor_name CURSOR FOR SELECT column1 FROM TableName;
3DECLARE cursor_name CURSOR FOR SELECT column2 FROM AnotherTable;

This example is problematic because it uses the same cursor name, cursor_name, more than once in the same scope. This can cause confusion about which cursor is being referenced and can make the code harder to debug.

• Leads to confusion over which cursor is active, potentially causing logic errors.

• Makes the codebase harder to maintain and understand, increasing the risk of errors during maintenance.

Ensure unique cursor names within the same scope to prevent logic errors and maintain code clarity.

Follow these steps to address the issue:

1. Identify the scope where the cursor is declared using the same name more than once.

2. Rename the newly declared cursor to a unique name that is not already used within the same scope. Use DECLARE to introduce the cursor with the new name.

3. Find all subsequent references to the original cursor name after the new declaration and update them to the new unique cursor name. Ensure that all OPEN, FETCH, CLOSE, and DEALLOCATE statements reflect this change.

For example:

1-- Corrected cursor declarations
2DECLARE cursor_name1 CURSOR FOR SELECT column1 FROM TableName;
3DECLARE cursor_name2 CURSOR FOR SELECT column2 FROM AnotherTable;
4
5-- Use the new cursor name in subsequent references
6OPEN cursor_name2;
7FETCH NEXT FROM cursor_name2 INTO @variable;
8CLOSE cursor_name2;
9DEALLOCATE cursor_name2;

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

Rule has no parameters.

The rule does not need Analysis Context or SQL Connection.

Design Rules, Bugs

DECLARE CURSOR (Transact-SQL)

Other Resources