Reports tables that contain two columns with an automatic increment. In MySQL, Microsoft SQL Server, and Db2 dialects, a table can have only one field with a auto-increment option, and this field must be a key.

Example (MySQL):

CREATE TABLE my_table
(
    id INT AUTO_INCREMENT,
    c2 INT AUTO_INCREMENT,
);

The AUTO_INCREMENT constraint for c2 will be highlighted as c1 already has this constraint. To fix the warning, you can make id a primary key and delete AUTO_INCREMENT for c2.

CREATE TABLE my_table
(
    id INT AUTO_INCREMENT PRIMARY KEY,
    c2 INT,
);