Confirm the target and the query
Start by confirming which connection, database, and environment the query uses. Development and production environments may have similar names while containing different records. Check the table or collection name and whether the connected account can read it; a successful connection does not prove that it points to the data you expected.
Next, temporarily review the filters and conditions. A date range, exact text match, or combined condition may exclude every record even when the collection is populated. Compare the query with one known record and add filters back one at a time so you can see which condition changes the result.
Separate missing data from missing access
If a simpler read still returns nothing, verify that the expected records exist through the database's usual administration or application path. If they exist there but not through the connection, investigate permissions, schema selection, and environment before attempting a write or changing the query broadly.
Keep this investigation read-only until you understand the mismatch. Record the connection and query that produced the empty result, along with the target environment. That context makes it easier to reproduce the issue and prevents a troubleshooting change from accidentally altering the wrong database.