substr

Description

Extracts a substring from a string starting at a given position, with an optional length. Useful for simple value extraction without needing regular expressions.

Syntax

Like many functions in DataPrime, substr supports two notations, function and method. These interchangeable forms allow flexibility in how you structure expressions.

Function notation

substr(value: string, from: number, length?: number): string

Method notation

(value: string).substr(from: number, length?: number): string

Arguments

Name	Type	Required	Description
value	string	true	The string to extract from
from	number	true	The starting index for the substring
length	number	false	Number of characters to return. Defaults to the remainder of the string

Example

Extract the value after a delimiter

Consider the following document:

{
    "msg": "result=Some value"
}

First, find the position of = with indexOf, then use substr to capture everything after it:

Example query

Function notation

create index_of_value from (indexOf(msg, '=') + 1)
| create value from substr(msg, index_of_value)

Method notation

create index_of_value from (msg.indexOf('=') + 1)
| create value from msg.substr(index_of_value)

Example output

{
    "msg": "result=Some value",
    "index_of_value": 7,
    "value": "Some value"
}