53 lines
1.6 KiB
Markdown
53 lines
1.6 KiB
Markdown
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## `TO_DOUBLE` [esql-to_double]
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**Syntax**
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:::{image} ../../../../../images/to_double.svg
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:alt: Embedded
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:class: text-center
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:::
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**Parameters**
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`field`
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: Input value. The input can be a single- or multi-valued column or an expression.
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**Description**
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Converts an input value to a double value. If the input parameter is of a date type, its value will be interpreted as milliseconds since the [Unix epoch](https://en.wikipedia.org/wiki/Unix_time), converted to double. Boolean **true** will be converted to double **1.0**, **false** to **0.0**.
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**Supported types**
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| field | result |
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| --- | --- |
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| boolean | double |
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| counter_double | double |
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| counter_integer | double |
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| counter_long | double |
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| date | double |
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| double | double |
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| integer | double |
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| keyword | double |
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| long | double |
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| text | double |
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| unsigned_long | double |
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**Example**
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```esql
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ROW str1 = "5.20128E11", str2 = "foo"
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| EVAL dbl = TO_DOUBLE("520128000000"), dbl1 = TO_DOUBLE(str1), dbl2 = TO_DOUBLE(str2)
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```
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| str1:keyword | str2:keyword | dbl:double | dbl1:double | dbl2:double |
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| --- | --- | --- | --- | --- |
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| 5.20128E11 | foo | 5.20128E11 | 5.20128E11 | null |
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Note that in this example, the last conversion of the string isn’t possible. When this happens, the result is a **null** value. In this case a *Warning* header is added to the response. The header will provide information on the source of the failure:
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`"Line 1:115: evaluation of [TO_DOUBLE(str2)] failed, treating result as null. Only first 20 failures recorded."`
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A following header will contain the failure reason and the offending value: `"java.lang.NumberFormatException: For input string: "foo""`
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