No matching data found in SSIs Lookup

 

The user has a function to update table data using txt, which is implemented using lookup. steps:

 

1. txt files in the cyclic folder

 

2. Use lookup to cache all target table data and compare TXT data with target table data.

 

 

3. Use TXT to update the target table if match data exists.

 

However, the data for each match is 0, and the TXT file does contain matched data. After turning over Microsoft's Bol, one sentence is very important:

If there are multiple matches in the reference table, The lookup transformation returns only the first match returned by the lookup query. if multiple matches are found, The lookup transformation generates an error or warning only when the transformation has been configured to load all the reference dataset into the cache. in this case, The lookup transformation generates a warning when the transformation detects multiple matches as the transformation fills the cache.

 

Later, I checked that all records in my records were repeated. Because I chose the "Redirect rows to no match output" method to handle errors, the data was not match.

 

Then try to delete the duplicate data. This problem is rarely encountered because most applications are in the data warehouse and all dimensions are one.

 

Another thing to note is that lookup is case sensitive and should be noted when processing data with characters.

 

In addition, this function can also be implemented by using the previous component that handles slow change dimensions.