Operator precedence¶

The following list shows the precedence of nGQL operators in descending order. Operators that are shown together on a line have the same precedence.

• - (negative number)
• !, NOT
• *, /, %
• -, +
• ==, >=, >, <=, <, <>, !=
• AND
• OR, XOR
• = (assignment)

For operators that occur at the same precedence level within an expression, evaluation proceeds left to right, with the exception that assignments evaluate right to left.

The precedence of operators determines the order of evaluation of terms in an expression. To modify this order and group terms explicitly, use parentheses.

Examples¶

nebula> RETURN 2+3*5;
+-----------+
| (2+(3*5)) |
+-----------+
| 17        |
+-----------+

nebula> RETURN (2+3)*5;
+-----------+
| ((2+3)*5) |
+-----------+
| 25        |
+-----------+

OpenCypher compatibility¶

In openCypher, comparisons can be chained arbitrarily, e.g., x < y <= z is equivalent to x < y AND y <= z in openCypher.

But in nGQL, x < y <= z is equivalent to (x < y) <= z. The result of (x < y) is a boolean. Compare it with an integer z, and you will get the final result NULL.