Some DBMSs have three valid values for this statement, Y, N, and D. See the DBMS-specific reference in this document for details about your DBMS.

The NULLS statement specifies whether the DBMS columns that are associated with the listed input SAS variables allow NULL values. Specify Y to accept NULL values. Specify N to reject NULL values and to require data in that column.

If you specify N for a numeric column, no observations that contain missing values in the corresponding SAS variable are loaded into the table. A message is written to the SAS log, and the current error count increases by one for each observation that is not loaded. See ERRLIMIT= statement for more information.

If a character column contains blanks (the SAS missing value) and you have specified N for the DBMS column, blanks are inserted. If you specify Y, NULL values are inserted.

The variable-identifier argument can be either the SAS variable name or the positional equivalent from the LIST statement. The positional equivalent is the number that represents the variable's place in the data set. For example, if you want the column that is associated with the third SAS variable to accept NULL values, submit this statement:

nulls 3=y;

If you omit the NULLS statement, the DBMS default action occurs. You can list as many variables as you want in one NULLS statement. If you have previously defined a column as NULLS=N, you can use the NULLS statement to redefine it to accept NULL values.