DQL operators
Numerical operators
The types long, double and timestamp real represent numerical types. The following operators can be used between pairs of these types
+
Addition
2+2.5
-
Subtraction
0.2-0.11
*
Multiplication
4*5, 60*1s
/
Division
10/2, 1h/60
%
Modulo
4%2
<
Lower
8 < 9, now()-1m < now()
<=
Lower than or equal
4<=5
>
Greater
5 > 4
>=
Greater than or equal
4 >=4
==
Equals
2 == 2
!=
Not equals
1 != 2
(long) (double)
(double) (double) (timestamp) (timestamp) (duration) (timeframe) (timeframe) (long) (double) (double) (double) (duration) (timestamp (duration) (timeframe) (long) (double) (duration) (double) (double) (duration, rounded to full nanos) (duration) (duration, rounded to full nanos) (long) (double) (double) (double) (duration) (duration rounded to full nanos) (double) (long) (double) (double) (double) (duration) (long) (double) (duration)Logical or equality operators
==
Equals - Yields true if both operands are not null and equal to each other. Otherwise, false.
2==2, "a" == "a"
!=
Not equals - Yields null, if one of the operands is null, or if the operands are not equal to each other.
2!=1, "b" != "a"
NOT
Negation - Negates a logical state
NOT 2==1
AND
Logical and (multiplication) - Yields true if both operands are true.
NOT 2==1 AND 1<2
OR
Logical or (addition) - Yields true if one of the operands is true, regardless of the other operand.
1 < 2 OR 1 > 2
XOR
Exclusive or - Yields true if one of the operands is true, but false in case both are true.
1 < 2 XOR 1 > 2
The behavior of logical operators follows the tri-state boolean logic.
-
AND
trueANDnull=nullnullANDtrue=nullfalseANDnull=falsenullANDfalse=falsenullANDnull=null
-
OR
trueORnull=truenullORtrue=truefalseORnull=nullnullORfalse=nullnullORnull=null
-
XOR
trueXORnull=nullnullXORtrue=nullfalseXORnull=nullnullXORfalse=nullnullXORnull=null
-
NOT
- NOT
null=null
- NOT
Equality comparisons (==, !=) use a tri-state boolean algebra (TRUE, FALSE, NULL). This means that if any side of the equality comparison is NULL, the overall result of the comparison is NULL.
There are two DQL functions that cover scenarios where missing or NULL records need to be retrieved:
For example, the below function that uses basic filtering does not provide null or missing records:
fetch logs| filter log.source != "logsourcename" // does not provide the records where `log.source` is null or missing
However, using the isTrueOrNull function renders those null and missing values:
fetch logs| filter isTrueOrNull(log.source != "logsourcename") // also provides the records where `log.source` is null or missing
String operators
By default, all string values in matching expressions are case-sensitive. The caseSensitive parameter provides the ability to change case sensitivity.
- For details see, string functions.
==
Equals
"ab" == lower("aB")
!=
Not equals
"ab" != "aB"
<
Lower
"b" < "c"
<=
Lower than or equal
"ab" <= "aB"
>
Greater
"a" > "A"
>=
Greater than or equal
"ab" >= "Ab"
- ( ) - false for non-comparable types in case of == operator, true for non-compatible types in case of != operator
- ( ) - true/false comparable types based on operator
- NULL - if one of the operands is NULL
- NULL == NULL - null
- ( ) - true/false based on result of operator
- ( ) - null
Iterative expressions
Iterative expressions can be used to evaluate every element of a given array or every i-th element of one or more arrays.
iAny
Checks an iterative boolean expression and returns true, if the expression was true at least once, false if it wasn't. For example:
fetch logs| fieldsAdd a = array(1, 2, 3)| filter iAny(a[] > 2)
iCollectArray
Collects the results of an iterative expression into an array. For example:
fetch logs| fieldsAdd a = array(1, 2, 3), b = array(10, 11, 12)| fieldsAdd iCollectArray(a[] + b[])
iIndex
Allows to access the index of an iterative expression element. For example, you can add the index of a value in the array and expand the array.
data record(a = array(2, 3, 7, 7, 1))| fields a = record(value = a[], index = iIndex())| expand a| fields value = a[value], index = a[index]
Comparison operators
in
The in comparison operator evaluates the occurrence of a value returned by the left side's expression within a list of values returned by the right side's DQL subquery.
Syntax
expression in [execution block]
Usage and constraints
left side
expression
yes
Either a field identifier or an expression.
The element to be found in the list returned by the right side's subquery.
right side
execution block
yes
It has to return a single field providing a list of values.
The DQL Subquery which returns the list of values to compare against.
Example
This example shows how to use the in keyword for filtering a host metric for the host's attribute:
timeseries avg(dt.host.cpu.usage), filter:dt.entity.host in [fetch dt.entity.host| fieldsAdd tags| expand tags| filter tags == "ServiceNow" | fields id]