SIGNUM

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Syntax

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Numeric or interval

signum(value)

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Arguments

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Numeric

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Interval

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Returns

• Type: DOUBLE
• Possible values: -1.0 for negative values, 0.0 for zero and 1.0 for positive values; numeric NaN remains NaN.
• NULL behavior: Returns NULL for a NULL numeric or interval input. Both positive and negative numeric zero produce 0.0; numeric NaN remains NaN.

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Properties

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Usage notes

• Numeric input is cast to DOUBLE before taking its sign.
• For year-month intervals the sign follows the month count. For day-time intervals it follows days plus milliseconds. For month-day-nanosecond intervals, a nonzero month component determines the sign; otherwise days plus nanoseconds determine it.
• INTEGER and INT mean the same type; STRING means VARCHAR text. NULL can be used with a supported type. Cast NULL explicitly when its type would otherwise be unclear.

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Examples

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Value and NULL input

SELECT signum(-5) AS negative, signum(0) AS zero, signum(5) AS positive, signum(CAST(NULL AS INT)) AS null_value;

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Interval sign and NULL

SELECT signum(INTERVAL '1' DAY) AS positive, signum(INTERVAL '-1' DAY) AS negative;