This topic will describe the comments in nGQL.

## Legacy version compatibility¶

• In Nebula Graph 1.0, there are four comment styles: #, --, //, /* */.
• In Nebula Graph 2.0, -- represents an edge pattern and cannot be used as comments.

## Examples¶

nebula> # Do nothing in this line
nebula> RETURN 1+1;     # This comment continues to the end of this line.
nebula> RETURN 1+1;     // This comment continues to the end of this line.
nebula> RETURN 1 /* This is an in-line comment. */ + 1 == 2;
nebula> RETURN 11 +            \
/* Multi-line comment.       \
Use a backslash as a line break.   \
*/ 12;


In nGQL statement, the backslash \ in a line indicates a line break.

## OpenCypher compatibility¶

• In nGQL, you must add a \ at the end of every line, even in multi-line comments /* */.
• In openCypher, there is no need to use a \ as a line break.
/* openCypher style:
The following comment
spans more than
one line */
MATCH (n:label)
RETURN n;

/* nGQL style:  \
The following comment       \
spans more than     \
one line */       \
MATCH (n:tag) \
RETURN n;


Last update: July 13, 2021