Alter

Add column

ADD COLUMN allows you to add a new column to a node/rel table. If you don’t specify a default value, the newly added column is filled with NULLs.

Column names must be unique within a node/relationship table.

For example, consider that you try to run the following command to add a column age, but it already exists in the User table:

ALTER TABLE User ADD age INT64;

The query will raise the following exception:

"Binder exception: Property: age already exists."

The following query adds a new column with the default value NULL to the User table.

ALTER TABLE User ADD grade INT64;

You can also specify the default value of the added column.

ALTER TABLE User ADD grade INT64 DEFAULT 40;

Drop column

DROP COLUMN allows you to remove a column from a table.

The following query drops the age column from the User table.

ALTER TABLE User DROP age;

Rename table

RENAME TABLE allows the user to rename a table.

The following query renames table User to Student.

ALTER TABLE User RENAME TO Student;

Rename column

RENAME COLUMN allows the user to rename a column of a table.

The following query renames the age column to grade.

ALTER TABLE User RENAME age TO grade;

Comment on a table

COMMENT ON allows you to add comments to a table.

The following query adds a comment to User table.

COMMENT ON TABLE User IS 'User information';

Comments can be extracted through SHOW_TABLES() function. See CALL for more information.

CALL SHOW_TABLES() RETURN *;
--------------------------------------------
| TableName | TableType | TableComment     |
--------------------------------------------
| User      | NODE      | User information |
--------------------------------------------
| City      | NODE      |                  |
--------------------------------------------