In Snowflake, the SUBSTRING function is used to extract a substring from a given string based on specified starting position and length. It allows you to retrieve a portion of a string based on character positions. Here's the syntax for the SUBSTRING function in Snowflake:
```
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SUBSTRING(string_expression, start_position, length)
```
The SUBSTRING function takes three arguments:
- **`string_expression`**: The source string from which the substring will be extracted.
- **`start_position`**: The starting position (index) within the source string where the extraction begins. The position starts from 1.
- **`length`** (optional): The length of the substring to be extracted. If not specified, it will extract the substring from the starting position to the end of the string.
Example usage:
```
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SELECT SUBSTRING('Snowflake', 3, 5) AS extracted_string;
```
This query will return the substring **`'owfla'`** since it starts at position 3 (inclusive) and has a length of 5 characters.
The SUBSTRING function is helpful when you need to extract a specific portion of a string based on its position and length. It can be useful for tasks such as parsing strings, manipulating text data, or extracting relevant information from structured strings.
Note that Snowflake uses 1-based indexing for string positions, meaning the first character in the string is at position 1.
