Conditional functions
Functions that return a conditional result.
coalesce
Returns the first non-null argument, if any, otherwise null.
Syntax
coalesce(expression, …)
Parameters
| Parameter | Type | Description | Required |
|---|---|---|---|
expression | array, boolean, double, duration, ip, long, record, string, timeframe, timestamp | Returned if previous arguments are | required |
Returns
Returns the first non-null argument, if any, otherwise null.
Examples
Example 1
data record(a = "a", b = "b", c = "c"),record(b = "b", c = "c"),record(c = "c"),record()| fieldsAdd coalesce(a, b, c)
Query result:
| a | b | c | coalesce(a, b, c) |
|---|---|---|---|
|
|
|
|
null |
|
|
|
null | null |
|
|
null | null | null | null |
if
Evaluates the condition, and returns the value of either the then or else parameter.
Syntax
if(condition, then [, else])
Parameters
| Parameter | Type | Description | Required |
|---|---|---|---|
condition | boolean | The condition to check. | required |
then | array, boolean, double, duration, ip, long, record, string, timeframe, timestamp | The expression if the condition is | required |
else | array, boolean, double, duration, ip, long, record, string, timeframe, timestamp | The expression if the condition is | optional |
Returns
Returns the value of the then parameter if the condition evaluated to true. Returns the value of the else parameter if the condition evaluated to false or null. Returns null if the condition evaluated to false or null and the else parameter is missing.
Examples
Example 1
data record(a = 10),record(a = 20)| fieldsAdd if(a < 15, "a is smaller than 15"),if(a < 15, "a is smaller than 15", else: "a is not smaller than 15")
Query result:
| a | if(a < 15, "a is smaller than 15") | if(a < 15, "a is smaller than 15", else:"a is not smaller than 15") |
|---|---|---|
|
|
|
| null |
|