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Comparators

Behavior

Comparing operators or comparators can be used in a match clause of a TypeQL query to compare by value two variables or a variable with a static value. You can use both concept variables and value variables with comparators. A concept variable must represent an attribute, since only attributes have values.

Comparators are always considered to return True. That sets a constraint on values that can be assigned to a variable used in a statement with a comparator.

The following operators are supported for comparing values: ==, !=, >, >=, <, and <=.

Equality comparator

For this example, use a database with the IAM schema and sample data loaded.

Use the double equal sign (==) to declare equality between two values.

For example, let’s find all files with a size attribute of value equal to 100:

Example
match
$file isa file,
    has path $filepath,
    has size-kb $size;
$size == 100;
get $filepath;

Since version 2.18.0 of TypeDB, the single equals sign (=) was deprecated as a comparison operator, as it can be used to assign a value to a value variable. It’s still possible to use it as a comparator for backward compatibility, but we recommend using == for equality instead.

Inequality comparator

For this example, use a database with the IAM schema and sample data loaded.

Use the exclamation mark with a single equal sign (!=) to declare inequality between two values.

For example, to find sizes for all files, that have filepath attribute of any value except the README.md:

Example
match
$file isa file,
    has path $filepath,
    has size-kb $size;
$filepath != "README.md";
get $size;

Greater than / Less than comparators

For this example, use a database with the IAM schema and sample data loaded.

Use the greater than sign (>) to declare the value/variable on the left from it as strictly greater than the one on the right from it. For a relaxed comparison, use the "greater than or equal" sign (>=).

Use the less than sign (<) to declare the value/variable on the left from it as strictly less than the one on the right from it. For a relaxed comparison, use the "less than or equal" sign (<=).

For example, use the following query to find all files that have an attribute of the size type and value less than or equal to 50.

Example
match
$file isa file,
    has path $filepath,
    has size-kb $size;
$size ≤ 100;
get $filepath;

String comparators

Contains

Use the contains keyword followed by a literal string to declare that the subject contains literal string as a substring.

The contains keyword is not case-sensitive.
Example
match
$p isa person, has full-name $name;
$name contains "kevin";
fetch $p: full-name;

Like

Use the like keyword followed by a regular expression pattern to declare that the subject has a string value that matches the regular expression.

Example
match
$p isa person, has full-name $name;
$name like "^(Kevin Morrison|Pearle Goodman)$";
fetch $p: full-name;