### IsNull (fld)

Basic and Crystal syntax.

##### Arguments

fld is any valid database, memo, or BLOB field.

##### Returns

Boolean Value

##### Action

Evaluates the field specified in the current record and returns TRUE if the field contains a null value.

##### Typical uses

You can use this function in a record selection formula to limit the report to records that have something other than a null value in the field specified. You can also use it to have the program take some action whenever it encounters a null value.

##### Examples

The following examples are applicable to both Basic and Crystal syntax:

IsNull({orders.ORDER AMOUNT}) = produces the following results:

If{orders.ORDER AMOUNT} shows this value | IsNull({orders.ORDER AMOUNT}) returns
200.00 | False
(null) | True
100.00 | False
347.12 | False

`Not IsNull({orders.ORDER AMOUNT})`

When used as a record selection formula, includes in the report only those records that have something other than a null value in the {orders.ORDER AMOUNT} field.

##### Comments

Some databases support null data values and others do not. This function will not work if the active database(s) do not support null values. If the database(s) do support null values, the function can be used to reference the null values that get created as the result of a failed lookup while joining.

Note: Zero and blank (empty or " ") are not null values.

###### Related topics

Null fields and how to use IsNull (Basic syntax)

Null fields and how to use IsNull (Crystal syntax)

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