Plus join

x pj y     pj[x;y]

Where

• x and y are tables
• y is keyed
• the key column/s of y are columns of x

returns x and y joined on the key columns of y.

pj adds matching records in y to those in x, by adding common columns, other than the key columns. These common columns must be of appropriate types for addition.

For each record in x:

• if there is a matching record in y it is added to the x record.
• if there is no matching record in y, common columns are left unchanged, and new columns are zero.