LASTSUBSTRINGBEFORE - Query language in Cosmos DB (in Azure and Fabric)

The LASTSUBSTRINGBEFORE function returns the substring before the last occurrence of a delimiter.

An Azure Cosmos DB system function that splits a string at the last delimiter and returns the prefix portion.

Syntax

LASTSUBSTRINGBEFORE(<string_expr_1>, <string_expr_2>)

Arguments

Return types

Returns a string expression.

Examples

This section contains examples of how to use this query language construct.

Get the text before the last delimiter

In this example, the LASTSUBSTRINGBEFORE function returns the portion before the last / character.

SELECT VALUE {
  parentPath: LASTSUBSTRINGBEFORE("/products/shoes/boots", "/"),
  prefix: LASTSUBSTRINGBEFORE("A-B-C", "-")
}

[
  {
    "parentPath": "/products/shoes",
    "prefix": "A-B"
  }
]

Get the text before the last string delimiter

In this example, the LASTSUBSTRINGBEFORE function returns the portion before the last :: delimiter.

SELECT VALUE {
  hierarchy: LASTSUBSTRINGBEFORE("bike::touring::frame", "::")
}

[
  {
    "hierarchy": "bike::touring"
  }
]

Remarks

• This function doesn't use the index.

Related content

• String functions
• SUBSTRINGBEFORE
• LASTSUBSTRINGAFTER