mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-13 02:53:38 +00:00
93 lines
3.4 KiB
Markdown
93 lines
3.4 KiB
Markdown
---
|
|
slug: /en/sql-reference/aggregate-functions/reference/grouparrayinsertat
|
|
sidebar_position: 112
|
|
---
|
|
|
|
# groupArrayInsertAt
|
|
|
|
Inserts a value into the array at the specified position.
|
|
|
|
**Syntax**
|
|
|
|
``` sql
|
|
groupArrayInsertAt(default_x, size)(x, pos)
|
|
```
|
|
|
|
If in one query several values are inserted into the same position, the function behaves in the following ways:
|
|
|
|
- If a query is executed in a single thread, the first one of the inserted values is used.
|
|
- If a query is executed in multiple threads, the resulting value is an undetermined one of the inserted values.
|
|
|
|
**Arguments**
|
|
|
|
- `x` — Value to be inserted. [Expression](../../../sql-reference/syntax.md#syntax-expressions) resulting in one of the [supported data types](../../../sql-reference/data-types/index.md).
|
|
- `pos` — Position at which the specified element `x` is to be inserted. Index numbering in the array starts from zero. [UInt32](../../../sql-reference/data-types/int-uint.md#uint-ranges).
|
|
- `default_x` — Default value for substituting in empty positions. Optional parameter. [Expression](../../../sql-reference/syntax.md#syntax-expressions) resulting in the data type configured for the `x` parameter. If `default_x` is not defined, the [default values](../../../sql-reference/statements/create/table.md#create-default-values) are used.
|
|
- `size` — Length of the resulting array. Optional parameter. When using this parameter, the default value `default_x` must be specified. [UInt32](../../../sql-reference/data-types/int-uint.md#uint-ranges).
|
|
|
|
**Returned value**
|
|
|
|
- Array with inserted values.
|
|
|
|
Type: [Array](../../../sql-reference/data-types/array.md#data-type-array).
|
|
|
|
**Example**
|
|
|
|
Query:
|
|
|
|
``` sql
|
|
SELECT groupArrayInsertAt(toString(number), number * 2) FROM numbers(5);
|
|
```
|
|
|
|
Result:
|
|
|
|
``` text
|
|
┌─groupArrayInsertAt(toString(number), multiply(number, 2))─┐
|
|
│ ['0','','1','','2','','3','','4'] │
|
|
└───────────────────────────────────────────────────────────┘
|
|
```
|
|
|
|
Query:
|
|
|
|
``` sql
|
|
SELECT groupArrayInsertAt('-')(toString(number), number * 2) FROM numbers(5);
|
|
```
|
|
|
|
Result:
|
|
|
|
``` text
|
|
┌─groupArrayInsertAt('-')(toString(number), multiply(number, 2))─┐
|
|
│ ['0','-','1','-','2','-','3','-','4'] │
|
|
└────────────────────────────────────────────────────────────────┘
|
|
```
|
|
|
|
Query:
|
|
|
|
``` sql
|
|
SELECT groupArrayInsertAt('-', 5)(toString(number), number * 2) FROM numbers(5);
|
|
```
|
|
|
|
Result:
|
|
|
|
``` text
|
|
┌─groupArrayInsertAt('-', 5)(toString(number), multiply(number, 2))─┐
|
|
│ ['0','-','1','-','2'] │
|
|
└───────────────────────────────────────────────────────────────────┘
|
|
```
|
|
|
|
Multi-threaded insertion of elements into one position.
|
|
|
|
Query:
|
|
|
|
``` sql
|
|
SELECT groupArrayInsertAt(number, 0) FROM numbers_mt(10) SETTINGS max_block_size = 1;
|
|
```
|
|
|
|
As a result of this query you get random integer in the `[0,9]` range. For example:
|
|
|
|
``` text
|
|
┌─groupArrayInsertAt(number, 0)─┐
|
|
│ [7] │
|
|
└───────────────────────────────┘
|
|
```
|