Sha256: 7e935ab2b86b810acfb46e398f854a71caf8da637c7298134d884986a400da03
Contents?: true
Size: 863 Bytes
Versions: 6
Compression:
Stored size: 863 Bytes
Contents
# Wrap Tuple-valued attribute ## Signature wrap(operand: Relation, attributes: AttrList, as: AttrName) -> Relation ## Examples wrap(suppliers, [:city, :status], :extra) wrap(suppliers, [:city, :status], :extra, allbut: true) ## Description Computes the relation obtained by removing `attributes` and replacing them by a single attribute (`as`). The latter is a tuple-valued attribute obtained by projecting the input tuple on `attributes`. This operators supports an ALL BUT variant, through the `allbut` option. When set to true, the operator keeps specified attributes and wraps all the remaining ones as a tuple-valued attribute. ## Implementation notes This operator does not compile to SQL so far. Contributions are welcome to provide it with a SQL compilation for SQL DBMSs that support this kind of feature (e.g. PostgreSQL with JSON data type)
Version data entries
6 entries across 6 versions & 1 rubygems