mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-19 22:22:00 +00:00
d91c97d15d
* Replace underscores with hyphens * remove temporary code * fix style check * fix collapse
115 lines
3.7 KiB
Markdown
115 lines
3.7 KiB
Markdown
---
|
||
toc_priority: 47
|
||
toc_title: Splitting and Merging Strings and Arrays
|
||
---
|
||
|
||
# Functions for Splitting and Merging Strings and Arrays {#functions-for-splitting-and-merging-strings-and-arrays}
|
||
|
||
## splitByChar(separator, s) {#splitbycharseparator-s}
|
||
|
||
Splits a string into substrings separated by a specified character. It uses a constant string `separator` which consisting of exactly one character.
|
||
Returns an array of selected substrings. Empty substrings may be selected if the separator occurs at the beginning or end of the string, or if there are multiple consecutive separators.
|
||
|
||
**Syntax**
|
||
|
||
``` sql
|
||
splitByChar(<separator>, <s>)
|
||
```
|
||
|
||
**Parameters**
|
||
|
||
- `separator` — The separator which should contain exactly one character. [String](../../sql-reference/data-types/string.md).
|
||
- `s` — The string to split. [String](../../sql-reference/data-types/string.md).
|
||
|
||
**Returned value(s)**
|
||
|
||
Returns an array of selected substrings. Empty substrings may be selected when:
|
||
|
||
- A separator occurs at the beginning or end of the string;
|
||
- There are multiple consecutive separators;
|
||
- The original string `s` is empty.
|
||
|
||
Type: [Array](../../sql-reference/data-types/array.md) of [String](../../sql-reference/data-types/string.md).
|
||
|
||
**Example**
|
||
|
||
``` sql
|
||
SELECT splitByChar(',', '1,2,3,abcde')
|
||
```
|
||
|
||
``` text
|
||
┌─splitByChar(',', '1,2,3,abcde')─┐
|
||
│ ['1','2','3','abcde'] │
|
||
└─────────────────────────────────┘
|
||
```
|
||
|
||
## splitByString(separator, s) {#splitbystringseparator-s}
|
||
|
||
Splits a string into substrings separated by a string. It uses a constant string `separator` of multiple characters as the separator. If the string `separator` is empty, it will split the string `s` into an array of single characters.
|
||
|
||
**Syntax**
|
||
|
||
``` sql
|
||
splitByString(<separator>, <s>)
|
||
```
|
||
|
||
**Parameters**
|
||
|
||
- `separator` — The separator. [String](../../sql-reference/data-types/string.md).
|
||
- `s` — The string to split. [String](../../sql-reference/data-types/string.md).
|
||
|
||
**Returned value(s)**
|
||
|
||
Returns an array of selected substrings. Empty substrings may be selected when:
|
||
|
||
Type: [Array](../../sql-reference/data-types/array.md) of [String](../../sql-reference/data-types/string.md).
|
||
|
||
- A non-empty separator occurs at the beginning or end of the string;
|
||
- There are multiple consecutive non-empty separators;
|
||
- The original string `s` is empty while the separator is not empty.
|
||
|
||
**Example**
|
||
|
||
``` sql
|
||
SELECT splitByString(', ', '1, 2 3, 4,5, abcde')
|
||
```
|
||
|
||
``` text
|
||
┌─splitByString(', ', '1, 2 3, 4,5, abcde')─┐
|
||
│ ['1','2 3','4,5','abcde'] │
|
||
└───────────────────────────────────────────┘
|
||
```
|
||
|
||
``` sql
|
||
SELECT splitByString('', 'abcde')
|
||
```
|
||
|
||
``` text
|
||
┌─splitByString('', 'abcde')─┐
|
||
│ ['a','b','c','d','e'] │
|
||
└────────────────────────────┘
|
||
```
|
||
|
||
## arrayStringConcat(arr\[, separator\]) {#arraystringconcatarr-separator}
|
||
|
||
Concatenates the strings listed in the array with the separator.’separator’ is an optional parameter: a constant string, set to an empty string by default.
|
||
Returns the string.
|
||
|
||
## alphaTokens(s) {#alphatokenss}
|
||
|
||
Selects substrings of consecutive bytes from the ranges a-z and A-Z.Returns an array of substrings.
|
||
|
||
**Example**
|
||
|
||
``` sql
|
||
SELECT alphaTokens('abca1abc')
|
||
```
|
||
|
||
``` text
|
||
┌─alphaTokens('abca1abc')─┐
|
||
│ ['abca','abc'] │
|
||
└─────────────────────────┘
|
||
```
|
||
|
||
[Original article](https://clickhouse.tech/docs/en/query_language/functions/splitting_merging_functions/) <!--hide-->
|