RETURN Syntax¶
The RETURN
statement is used to return the result when the condition is true. If the condition is false, no result is returned.
RETURN <var_ref> IF <var_ref> IS NOT NULL
is a variable name, e.g. $var
.
Examples¶
nebula> $A = GO FROM 100 OVER follow YIELD follow._dst AS dst; \
$rA = YIELD $A.* WHERE $A.dst == 101; \
RETURN $rA IF $rA is NOT NULL; \ /* Returns the result because $rA is not empty */
GO FROM $A.dst OVER follow; /* As the RETURN statement returns the result, the GO FROM statement is not executed*/
==========
| $A.dst |
==========
| 101 |
----------
nebula> $A = GO FROM 100 OVER follow YIELD follow._dst AS dst; \
$rA = YIELD $A.* WHERE $A.dst == 300; \
RETURN $rA IF $rA is NOT NULL; \ /* Does not return the result because $rA is empty */
GO FROM $A.dst OVER follow; /* As the RETURN statement does not return the result, the GO FROM statement is executed */
===============
| follow._dst |
===============
| 100 |
---------------
| 101 |
---------------
| 100 |
---------------
| 102 |
---------------
| 100 |
---------------
| 107 |
---------------