MarkLogic 10 Product Documentationop.bucketGroup
op.bucketGroup( name as String, column as columnIdentifier, boundaries as xs.anyAtomicType[], [collation as String?] ) as NamedColumnGroup
Summary
This function can be used as a named group in functions prototype.groupToArrays or prototype.facetBy . After grouping, the plan can also join a literal table with descriptive metadata based for each bucket number. Developers can handle special cases by taking the same approach as the convenience function and binding a new column on the return value of an sql.bucket expression on a numeric or datetime column to use as a grouping key.
| Parameters | |
|---|---|
| name | The name of both the group and the new grouping key column with numbered buckets. |
| column | The identifier for the existing column with the values (typically numeric or datetime) to put into buckets. The columns can be named with a string or a column parameter function such as op.col or constructed from an expression with op.as. |
| boundaries | An ordered JavaScript array of values that specify the boundaries between buckets. The values must have the same type as the existing column. |
| collation | The collation to use when comparing strings as described in 'Collation URI Syntax' in the Application Developer's Guide. |
See Also
Example
const op = require('/MarkLogic/optic');
op.fromLiterals([
{'r':1, 'c1':'a', 'c2':'x', 'c3':'m'},
{'r':2, 'c1':'b', 'c2':'x' },
{'r':3, 'c1':'a', 'c3':'n'},
{'r':4, 'c2':'y', 'c3':'o'},
{'r':5, 'c1':'b' },
{'r':6, 'c2':'y' },
{'r':7, 'c3':'p'},
{'r':8, 'c1':'b', 'c2':'x', 'c3':'q'}
])
.groupToArrays(
[op.bucketGroup('rBucket', op.col("r"), [2,4])],
[op.count('numRows')]
)
.result();