Code Inspection: Ambiguous reference

Reports columns that have identical names but belong to different tables.

Example (MySQL):

CREATE TABLE foo(id INT PRIMARY KEY);
CREATE TABLE bar(id INT PRIMARY KEY);

SELECT foo.id, bar.id FROM foo, bar WHERE id > 0;

The id column appears in foo and bar tables. You need to qualify the column name to make the query correct.

SELECT foo.id, bar.id FROM foo, bar WHERE foo.id > 0;