Developer Documentation Library > Data Model > Available DSCs > UNICOM Intelligence Data File CDSC > Natively supported WHERE expressions
 
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.
See also
UNICOM Intelligence Data File schema
Transferring hierarchical data to a UNICOM Intelligence Data File
Custom connection properties used by the UNICOM Intelligence Data File CDSC
UNICOM Intelligence Data File CDSC: Supported CDSC features
SQLite and multiple users
Indexing UNICOM Intelligence Data Files
Compressed UNICOM Intelligence Data Files
UNICOM Intelligence Data File CDSC