Is-Of-Type Operator

The is-of-type operator checks the sequence type of its input sequence against one or more target sequence types. If the number N of the target types is greater than one, the expression is equivalent to OR-ing N is-of-type expressions, each having one target type.

Example: Fetch the names of the passengers whose baggage tags contain only numbers and not a STRING.

SELECT fullname,bag.bagInfo.tagNum 
FROM  BaggageInfo bag 
WHERE bag.bagInfo.tagNum is of type (NUMBER)

Explanation: The tagNum in the bagInfo schema is a STRING data type. But the application could take in a NUMBER value as tagNum by mistake. The query captures the passengers for whom the tagNum column has only numbers.

Output:

{"fullname":"Raymond Griffin","tagNum":17657806243578}

If you query the bagInfo schema for the above tagNum as STRING, no rows are displayed.

SELECT * FROM BaggageInfo bag WHERE tagnum = "17657806232501"
0 row returned

You can also fetch the names of the passengers whose baggage tags contain only STRING.

SELECT fullname,bag.bagInfo.tagNum 
FROM BaggageInfo bag 
WHERE  bag.bagInfo.tagNum is of type (STRING)