Why is this SQLquery in Matlab returning repeated records?

I used JDBC driver to connect to the mySQL DB in Matlab. The connection works. However, when I used following SQLquery in Matlab to get data:

SQLquery = ['SELECT * FROM db_XYZ WHERE Col_Name=' '''Col_A'''];

I got repeated (always three times) results shown as below:

1 Col_A CA SFO 1 Col_A CA SFO 1 Col_A Ca SFO

There is only row of "1 Col_A Ca SFO" in the database table.

Why? Thanks...

Answer 1

[colordepth]

The query syntax appears to be correct. Start by inspecting the MATLAB result structure to confirm the number of rows returned by MATLAB:

disp(size(fetchedData))

If it shows duplicates (e.g., 3 rows), proceed to validate the database:

1. Run the query directly in MySQL (e.g., via Workbench).
2. Use a SELECT COUNT query to confirm the number of matching rows in the database.

If the database returns 1 row but MATLAB shows duplicates, the issue is not database-level. This indicates MATLAB is appending results (e.g., repeated fetch calls or code logic like loops). If both the database and MATLAB show duplicates, check for triggers using:

SHOW TRIGGERS FROM your_database;