StringToNumber (Azure Cosmos DB)

APPLIES TO: SQL API

Returns expression translated to a Number. If expression cannot be translated, returns undefined.

Syntax

StringToNumber(<str_expr>)  

Arguments

str_expr
Is a string expression to be parsed as a JSON Number expression. Numbers in JSON must be an integer or a floating point. For details on the JSON format, see json.org

Return types

Returns a Number expression or undefined.

Examples

The following example shows how StringToNumber behaves across different types.

Whitespace is allowed only before or after the Number.

SELECT 
    StringToNumber("1.000000") AS num1, 
    StringToNumber("3.14") AS num2,
    StringToNumber("   60   ") AS num3, 
    StringToNumber("-1.79769e+308") AS num4

Here is the result set.

{{"num1": 1, "num2": 3.14, "num3": 60, "num4": -1.79769e+308}}

In JSON a valid Number must be either be an integer or a floating point number.

SELECT   
    StringToNumber("0xF")

Here is the result set.

{{}}

The expression passed will be parsed as a Number expression; these inputs do not evaluate to type Number and thus return undefined.

SELECT 
    StringToNumber("99     54"),   
    StringToNumber(undefined),
    StringToNumber("false"),
    StringToNumber(false),
    StringToNumber(" "),
    StringToNumber(NaN)

Here is the result set.

{{}}

Remarks

This system function will not utilize the index.

Next steps