To properly join two tables in Qlik Sense while avoiding data mismatch issues, you need to ensure that the filters are applied correctly. Here are some steps you can take:
1. Verify that the ID column in both tables has the same data type and format. Any discrepancies in data types or formats can cause issues during the join operation.
2. Use the "Keep" prefix when loading the tables to preserve the original data structure and avoid automatic concatenation. This will allow you to control the join operation explicitly.
3. Perform an inner join between the two tables using the ID column as the join key. This will ensure that only records with matching ID values from both tables are included in the result.
4. Apply filters after the join operation to avoid any unintended data loss or mismatch. Filters applied before the join can potentially exclude records that should be included in the join result.
5. If you need to apply filters before the join, use the "Qualify" prefix to create a temporary table with the desired filters, and then join this temporary table with the other table.
6. Verify the join result by checking the number of records and the data distribution. You can use the "Peek" function or create a visualization to inspect the joined data.
By following these steps, you should be able to join the two tables correctly while maintaining data integrity and avoiding any data mismatch issues caused by improper filter application.
