Natively supported WHERE expressions

Developer Documentation Library > Data Model > Available DSCs > UNICOM Intelligence Data File CDSC > Natively supported WHERE expressions

Starting with UNICOM Intelligence Data Model 5.6, the UNICOM Intelligence Data File (DDF) CDSC natively supports a variety of WHERE expression types. Natively evaluated WHERE expressions are extremely fast, and can improve overall UNICOM Intelligence Data File DSC performance. The following table lists the supported WHERE expression types:

Type	- (negative)	Logical (and, or)	=	<>	>	<	>=	<=	Is NULL	Is Not NULL
mtLong	√		√	√	√	√	√	√	√	√
mtText			√	√	√	√	√	√	√	√
mtDouble	√		√	√	√	√	√	√	√	√
mtBool			√	√					√	√
mtDate			√	√	√	√	√	√	√	√
mtCategorical*					√				√	√
Simple Expression composed by permitted expression		√

The columns must be in the HDATA top level, and mtCategorical only supports compare > with {}.

WHERE expressions are also natively evaluated in the following conditions:

▪mtLong variable compared with mtDouble value

▪mtDouble variable compared with mtLong value

▪mtText variable compared with mtLong value and the comparison operator is =

▪mtBoolean variable compared with Permitted Simple Expression

▪When the same kind of allowed variables (except mtCategorical) are compared.