Graph database_Neo4j learning cypher language_Using CQL command 003_NULL value operation_IN operator_Create index_Create constraint_Delete index_Delete constraint_Common functions---Neo4j graph database work notes 0007

Then let’s take a look at the null value in the graph database

 

can be seen here

match (n:'西游') where n.label is not null return id(n),n.name, n.tail,n.label

You can see here that in Journey to the West, the label attribute of the node is not null and is displayed. You can see that it is not, right?

The label nodes corresponding to all data are null because

 

Let's go see another one

for example:

match (n:student {name:"张三"}) set n.age=18,n.sex='Male' return n

After execution, you can see that there is an additional age and an additional sex attribute, right?

Then we write sex as an empty string and then execute it

You can see that sex is empty