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ISNULL
Returns the boolean value true if the value passed to the function is a NULL else returns false.
Should not be used to check the value of the database field because even when value of the field in database is NULL it might not be NULL in the record’s DataSource. Namely all integer values will be set to 0 in DataSource when they are NULL in the database, string values are set to an empty string when they are NULL in database and so on.
To check if the value is NULL in the database use different approach: instead of
If(ISNULL(QuantityPerUnit), “true”, “false”)
in Products table resord use QuantityPerUnitSpecified property in the record control:
If(ProductsRecordControl.DataSource.QuantityPerUnitSpecified, “true”, “false”)
Or
If(ProductsTableControlRow.DataSource.QuantityPerUnitSpecified, “true”, “false”)
Syntax
= ISNULL(value)
Parameters
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Value |
A value which has to be checked. The value can be specified as a decimal value (e.g., 37.48), as a string (“True”), as a Boolean (e.g., True), as an expression (e.g., 1+1=2). |
Return Type
Boolean
Examples
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Example |
Returns |
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= ISNULL(“a”) |
False |
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= ISNULL(1234) |
False |
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= ISNULL(1+1=2) |
False |