Withinrow

Withinrow is a term encountered in data processing and software libraries describing a row-oriented predicate that evaluates a value against data located in the same row of a table or record set. In practice, withinrow can refer to two related patterns. The first is membership within the row: a test whether a given value matches any of the values held in other columns of the same row. The second is range containment: a test whether a value falls within a numeric or categorical range defined by columns in the same row, for example a value between min_value and max_value.

Usage of withinrow is typically in per-row validation, filtering, or constraint checking. It is evaluated independently for each row, enabling row-wise data integrity checks without cross-row references. This makes it useful in data cleaning and validation pipelines where row-local conditions are sufficient to determine acceptability.

Example: suppose a row has fields min_value, max_value, and candidate. withinrow(candidate) would be true if min_value <= candidate <= max_value. Alternatively, for membership, a test could check whether candidate matches any of the fields a, b, c within the same row.

Implementation notes depend on the language or library. Withinrow is often expressed as a row-wise map operation or a vectorized expression. Performance considerations include avoiding excessive copying and ensuring proper handling of null values.

See also: row-wise operations, range checks, data validation, per-row computation. History: the term is used informally in tutorials and documentation; there is no universal standard specification for withinrow across programming environments.