QlikView Reference Manual.pdf - QlikCommunity - QlikView

NullAsValue
By default, QlikView considers NULL values to be missing or undefined entities. However, certain database
contexts imply that NULL values are to be considered as special values rather than simply missing values.
The fact that NULL values are normally not allowed to link to other NULL values can be suspended by
means of the NullAsValue statement. Thus the NULL values of the specified fields are considered to be
unknown rather than undefined when the NullAsValue statement is employed. The NullAsValue statement
could be considered to supersede the NullDisplay (page 275) variable at field level.
The NullAsValue statement operates as a switch. It can be switched off again by means of the NullAsNull
(page 255) statement.
The syntax is:
NullAsValue*fieldlist
*fieldlist is a comma separated list of the fields for which NullAsValue should be turned on. Using * as
field list indicates all fields. The wildcard characters * and ? are allowed in field names. Quoting of field
names may be necessary when wildcards are used.
Example:
NullAsValue A,B;
Load A,B from x.csv;
Please note the following points when using the NullAsValue statement:
l Linking of NULL values is always turned off by default at the beginning of script execution.
l Linking of NULL values of a specific field can be activated at any time using a NullAsValue statement.
Back to Script Statements and Keywords (page 219).
NullAsNull
The NullAsNull statement turns off the linking of NULL values previously set by a NullAsValue (page 255)
statement (follow this link for more information).
The syntax is:
NullAsNull*fieldlist
*fieldlist is a comma separated list of the fields for which NullAsNull should be turned on. Using * as field
list indicates all fields. The wildcard characters * and ? are allowed in field names. Quoting of field names
may be necessary when wildcards are used.
Examples:
NullAsNull A,B;
Load A,B from x.csv;
Back to Script Statements and Keywords (page 219).
Outer
The explicit Join (page 243) prefix can be preceded by the prefix outer in order to specify an outer join. In
an outer join all combinations between the two tables are generated. The outer keyword is optional.
outer join [ (tablename ) ](loadstatement |selectstatement )
Example:
255