Changes for version 0.51 - 2026-10-13
- Enhancements
- selectall_arrayref(): new distinct => 1 parameter deduplicates the result set. On SQL-capable backends (SQLite, PostgreSQL, MySQL, DBD::CSV >= 0.64) it emits SELECT DISTINCT; on the slurp/in-memory path Perl-side deduplication is performed by _apply_distinct(). Requires DBD::CSV >= 0.64 (SQL::Statement >= 1.414) for the CSV backend; minimum version raised accordingly in Makefile.PL and cpanfile.
- selectall_arrayref(): new columns => \@cols parameter restricts which columns appear in the returned rows; column names are validated with SAFE_QUALIFIED; missing keys in fixated slurp rows are returned as undef. Can be used independently or together with distinct => 1. Note: _apply_distinct() runs after sort/offset/limit, so limit => N, distinct => 1 deduplicates the already-limited slice, not the full set.
- aggregate(): added median and stddev to the measure vocabulary. Both are Perl-fold-only (no SQL pushdown); on SQL-backed databases the full matching result set is fetched and then folded in memory. median: middle value for odd count, average of two middle values for even count; undef for empty group. stddev: sample standard deviation (N-1 denominator); 0 for single-row group, undef for empty group.
Documentation
Modules
Read-only Database Abstraction Layer (ORM)
Fluent, chainable query builder for Database::Abstraction