你当前正在访问 Microsoft Azure Global Edition 技术文档网站。 如果需要访问由世纪互联运营的 Microsoft Azure 中国技术文档网站，请访问 https://docs.azure.cn。

substring()

Applies to: ✅ Microsoft Fabric ✅ Azure Data Explorer ✅ Azure Monitor ✅ Microsoft Sentinel

Extracts a substring from the source string starting from some index to the end of the string.

Optionally, the length of the requested substring can be specified.

Syntax

substring(source, startingIndex [, length])

Learn more about syntax conventions.

Parameters

Name	Type	Required	Description
source	string	✔️	The string from which to take the substring.
startingIndex	int	✔️	The zero-based starting character position of the requested substring. If a negative number, the substring will be retrieved from the end of the source string.
length	int		The requested number of characters in the substring. The default behavior is to take from startingIndex to the end of the source string.

Returns

A substring from the given string. The substring starts at startingIndex (zero-based) character position and continues to the end of the string or length characters if specified.

Examples

substring("123456", 1)        // 23456
substring("123456", 2, 2)     // 34
substring("ABCD", 0, 2)       // AB
substring("123456", -2, 2)    // 56