Skip to content
Merged
Show file tree
Hide file tree
Changes from 3 commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
172 changes: 172 additions & 0 deletions datafusion/functions-nested/src/array_compact.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,172 @@
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.

//! [`ScalarUDFImpl`] definitions for array_compact function.

use crate::utils::make_scalar_function;
use arrow::array::{
Array, ArrayRef, Capacities, GenericListArray, MutableArrayData, NullBufferBuilder,
OffsetSizeTrait, make_array,
};
use arrow::buffer::OffsetBuffer;
use arrow::datatypes::DataType;
use arrow::datatypes::DataType::{LargeList, List, Null};
use datafusion_common::cast::{as_large_list_array, as_list_array};
use datafusion_common::{Result, exec_err, utils::take_function_args};
use datafusion_expr::{
ColumnarValue, Documentation, ScalarFunctionArgs, ScalarUDFImpl, Signature,
Volatility,
};
use datafusion_macros::user_doc;
use std::sync::Arc;

make_udf_expr_and_func!(
ArrayCompact,
array_compact,
array,
"removes null values from the array.",
array_compact_udf
);

#[user_doc(
doc_section(label = "Array Functions"),
description = "Removes null values from the array.",
syntax_example = "array_compact(array)",
sql_example = r#"```sql
> select array_compact([1, NULL, 2, NULL, 3]) arr;
+-----------+
| arr |
+-----------+
| [1, 2, 3] |
+-----------+
```"#,
argument(
name = "array",
description = "Array expression. Can be a constant, column, or function, and any combination of array operators."
)
)]
#[derive(Debug, PartialEq, Eq, Hash)]
pub struct ArrayCompact {
signature: Signature,
aliases: Vec<String>,
}

impl Default for ArrayCompact {
fn default() -> Self {
Self::new()
}
}

impl ArrayCompact {
pub fn new() -> Self {
Self {
signature: Signature::array(Volatility::Immutable),
aliases: vec!["list_compact".to_string()],
}
}
}

impl ScalarUDFImpl for ArrayCompact {
fn name(&self) -> &str {
"array_compact"
}

fn signature(&self) -> &Signature {
&self.signature
}

fn return_type(&self, arg_types: &[DataType]) -> Result<DataType> {
Ok(arg_types[0].clone())
}

fn invoke_with_args(&self, args: ScalarFunctionArgs) -> Result<ColumnarValue> {
make_scalar_function(array_compact_inner)(&args.args)
}

fn aliases(&self) -> &[String] {
&self.aliases
}

fn documentation(&self) -> Option<&Documentation> {
self.doc()
}
}

/// array_compact SQL function
pub fn array_compact_inner(arg: &[ArrayRef]) -> Result<ArrayRef> {

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
pub fn array_compact_inner(arg: &[ArrayRef]) -> Result<ArrayRef> {
fn array_compact_inner(arg: &[ArrayRef]) -> Result<ArrayRef> {

let [input_array] = take_function_args("array_compact", arg)?;

match &input_array.data_type() {
List(field) => {
let array = as_list_array(input_array)?;
compact_list::<i32>(array, field)
}
LargeList(field) => {
let array = as_large_list_array(input_array)?;
compact_list::<i64>(array, field)
}
Null => Ok(Arc::clone(input_array)),
array_type => exec_err!("array_compact does not support type '{array_type}'."),
}
}

/// Remove null elements from each row of a list array.
fn compact_list<O: OffsetSizeTrait>(
list_array: &GenericListArray<O>,
field: &Arc<arrow::datatypes::Field>,
) -> Result<ArrayRef> {
let values = list_array.values();
let original_data = values.to_data();
let mut offsets = Vec::<O>::with_capacity(list_array.len() + 1);
offsets.push(O::zero());
let mut mutable = MutableArrayData::with_capacities(
vec![&original_data],
false,
Capacities::Array(original_data.len()),
);
let mut valid = NullBufferBuilder::new(list_array.len());

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Can directly grab null buffer from input array for the output array to avoid needing a builder here


for row_index in 0..list_array.len() {

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

let nulls = list_array.nulls();
for row_index in 0..list_array.len() {
  if nulls.is_some_and(|n| n.is_null(row_index)) {
    offsets.push(offsets[row_index]);
    continue;
  }

would make it consistent with behavior in #21482 and #21532

if list_array.is_null(row_index) {
offsets.push(offsets[row_index]);
valid.append_null();
continue;
}

let start = list_array.offsets()[row_index].as_usize();
let end = list_array.offsets()[row_index + 1].as_usize();
let mut copied = 0usize;

for i in start..end {
if !values.is_null(i) {
mutable.extend(0, i, i + 1);
copied += 1;
}
}

offsets.push(offsets[row_index] + O::usize_as(copied));
valid.append_non_null();
}

let new_values = make_array(mutable.freeze());
Ok(Arc::new(GenericListArray::<O>::try_new(
Arc::clone(field),
OffsetBuffer::new(offsets.into()),
new_values,
valid.finish(),
)?))
}
3 changes: 3 additions & 0 deletions datafusion/functions-nested/src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -37,6 +37,7 @@
#[macro_use]
pub mod macros;

pub mod array_compact;
pub mod array_has;
pub mod arrays_zip;
pub mod cardinality;
Expand Down Expand Up @@ -77,6 +78,7 @@ use std::sync::Arc;

/// Fluent-style API for creating `Expr`s
pub mod expr_fn {
pub use super::array_compact::array_compact;
pub use super::array_has::array_has;
pub use super::array_has::array_has_all;
pub use super::array_has::array_has_any;
Expand Down Expand Up @@ -128,6 +130,7 @@ pub mod expr_fn {
/// Return all default nested type functions
pub fn all_default_nested_functions() -> Vec<Arc<ScalarUDF>> {
vec![
array_compact::array_compact_udf(),
string::array_to_string_udf(),
string::string_to_array_udf(),
range::range_udf(),
Expand Down
82 changes: 82 additions & 0 deletions datafusion/sqllogictest/test_files/array.slt
Original file line number Diff line number Diff line change
Expand Up @@ -7641,6 +7641,88 @@ from array_distinct_table_2D_fixed;
[[1, 2], [3, 4], [5, 6], [7, 8], [9, 10]]
[[5, 6], NULL]

## array_compact (aliases: `list_compact`)

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Should we also add a test for fixedsizelist?


# basic: remove nulls from integer array
query ?
select array_compact([1, NULL, 2, NULL, 3]);
----
[1, 2, 3]

# no nulls present
query ?
select array_compact([1, 2, 3]);
----
[1, 2, 3]

# all nulls
query ?
select array_compact(arrow_cast([NULL, NULL, NULL], 'List(Int64)'));
----
[]

# empty array
query ?
select array_compact([]);
----
[]

# NULL input returns NULL
query ?
select array_compact(NULL::INT[]);
----
NULL

# string array
query ?
select array_compact(['a', NULL, 'b', NULL, 'c']);
----
[a, b, c]

# float array
query ?
select array_compact([1.0, NULL, 2.0, NULL]);
----
[1.0, 2.0]

# nested array (2D)
query ?
select array_compact([make_array(1, 2), NULL, make_array(3, 4)]);
----
[[1, 2], [3, 4]]

# LargeList
query ?
select array_compact(arrow_cast([1, NULL, 2, NULL, 3], 'LargeList(Int64)'));
----
[1, 2, 3]

# alias list_compact
query ?
select list_compact([1, NULL, 2]);
----
[1, 2]

# table-based test
statement ok
CREATE TABLE array_compact_table AS VALUES
(make_array(1, NULL, 2, NULL, 3)),
(make_array(NULL, NULL, NULL)),
(make_array(4, 5, 6)),
(NULL::INT[])
;

query ?
select array_compact(column1) from array_compact_table;
----
[1, 2, 3]
[]
[4, 5, 6]
NULL

statement ok
DROP TABLE array_compact_table;

## arrays_zip (aliases: `list_zip`)

# Spark example: arrays_zip(array(1, 2, 3), array(2, 3, 4))
Expand Down
33 changes: 33 additions & 0 deletions docs/source/user-guide/sql/scalar_functions.md
Original file line number Diff line number Diff line change
Expand Up @@ -3237,6 +3237,7 @@ _Alias of [current_date](#current_date)._
- [array_any_value](#array_any_value)
- [array_append](#array_append)
- [array_cat](#array_cat)
- [array_compact](#array_compact)
- [array_concat](#array_concat)
- [array_contains](#array_contains)
- [array_dims](#array_dims)
Expand Down Expand Up @@ -3285,6 +3286,7 @@ _Alias of [current_date](#current_date)._
- [list_any_value](#list_any_value)
- [list_append](#list_append)
- [list_cat](#list_cat)
- [list_compact](#list_compact)
- [list_concat](#list_concat)
- [list_contains](#list_contains)
- [list_dims](#list_dims)
Expand Down Expand Up @@ -3391,6 +3393,33 @@ array_append(array, element)

_Alias of [array_concat](#array_concat)._

### `array_compact`

Removes null values from the array.

```sql
array_compact(array)
```

#### Arguments

- **array**: Array expression. Can be a constant, column, or function, and any combination of array operators.

#### Example

```sql
> select array_compact([1, NULL, 2, NULL, 3]) arr;
+-----------+
| arr |
+-----------+
| [1, 2, 3] |
+-----------+
```

#### Aliases

- list_compact

### `array_concat`

Concatenates arrays.
Expand Down Expand Up @@ -4535,6 +4564,10 @@ _Alias of [array_append](#array_append)._

_Alias of [array_concat](#array_concat)._

### `list_compact`

_Alias of [array_compact](#array_compact)._

### `list_concat`

_Alias of [array_concat](#array_concat)._
Expand Down
Loading