Merge Update

Description Update merge updates a dataset with values from a second dataset based on exact variable name matching for observations with matching join mapping variable values. You need to specify one or more variables in the active dataset and in the selected target dataset that you want the join to be performed on. The results will be saved in a new dataset.

Merge Options

Update variables in first (left) dataset with matches from second (right) dataset, insert non-matches:

This is a combination of updating variables in the left dataset for matches and creating new rows for unmatched rows.

Update variables in first (left) dataset with matches from second (right) dataset, ignore non-matches:

This only updates existing variables in the left datasets for matches. Unmatched rows are ignored.

Only insert non-matches in first (left) dataset:

This leaves intact all matching rows in the left dataset. Only non-matching rows from the right dataset are added to the left dataset.

Update only variables with NAs in first (left) dataset with matches from second (right) dataset, ignore non-matches:

This updates rows that match, but only when the values in the left dataset are NA (i.e. are missing values).

Delete rows from first (left) dataset with matches from second (right) dataset:

This only deletes rows from the left dataset that match rows in the right dataset.