The following are the supported basic data types by the DVR Query language:
Integer
A signed 64-bit integer data type. Example: 10, -12
String
A sequence of characters. Example: "Hello, world!"
Boolean
A binary value that can be either true or false
Operators
The list of supported operators:
Boolean Operators:
or
and
Relational Operators: >, >=, <, <=
Applies to integer
Equality Operators
Equality operator:==
Applies to boolean, integer, and string.
In the case of a string, this is a case-sensitive comparison.
Inequality operator:!=
Applies to boolean, integer, string
String-specific Relational Operations
~!=
Case-insensitive inequality operation on a string
~==
Case-insensitive equality operation on string
Variable and Literals
The zkPass Query language also defines the following concepts:
Variable
The variable corresponds to the key name of the key/value json element in the query data. To reference nested elements in the json data, delimiter “.” is used as the path separator.
The variable must appear on the left-hand side of a relational expression.
Literal (Constant)
The constant value is compared to the variable's value.
The literal must appear on the right-hand side of a relational expression. The data type of the literal must match that of the variable.