reifydb_core/value/column/view/
group_by.rs

1// Copyright (c) reifydb.com 2025
2// This file is licensed under the AGPL-3.0-or-later, see license.md file
3
4use std::collections::HashMap;
5
6use reifydb_type::{Value, diagnostic::engine, error};
7
8use crate::value::column::{ColumnData, Columns};
9
10pub type GroupKey = Vec<Value>;
11pub type GroupByView = HashMap<GroupKey, Vec<usize>>;
12
13impl<'a> Columns<'a> {
14	pub fn group_by_view(&self, keys: &[&str]) -> crate::Result<GroupByView> {
15		let row_count = self.first().map_or(0, |c| c.data().len());
16
17		let mut key_columns: Vec<&ColumnData> = Vec::with_capacity(keys.len());
18
19		for &key in keys {
20			let column = self
21				.iter()
22				.find(|c| c.name() == key)
23				.ok_or_else(|| error!(engine::frame_error(format!("Column '{}' not found", key))))?;
24			key_columns.push(&column.data());
25		}
26
27		let mut result = GroupByView::new();
28
29		for row_numberx in 0..row_count {
30			let mut values = Vec::with_capacity(keys.len());
31
32			for col in &key_columns {
33				let value = col.get_value(row_numberx);
34				values.push(value);
35			}
36
37			result.entry(values).or_default().push(row_numberx);
38		}
39
40		Ok(result)
41	}
42}