neo4j - Difference between merge and create in Cypher -


  1. Can anyone tell me that there is a difference between merge and create in Caesars Q & A?
  2. How does Neo4j store physical data?

    Thank you in advance ..

    create only makes it what it says, and if it means to make a duplicate, then it makes sense. MERGE is created equally, but also checks to see if a node with the properties you specify already exists. If this happens, then it does not produce. Here's an example: It helps to avoid duplicate. I use the create twice to create a person with the same name. neo4j-sh (?) $ Make (page: person {name: "bob"}); + ------------------- + | No data returned. + ------------------- + Built-in node: 1 property set: 1 label added: 19 ms neo4j-sh (?) $ Make (p: person {name} : "Bob"}); + ------------------- + | No data returned. + ------------------- + Built-in node: 1 property set: 1 label added: 1 5 ms

    So now when We have two bob, query. 

      neo4j-sh (?) $ Match (page: person {name: "bob"}) return page; + ---------------------- + + | P | + ---------------------- + + | Node [222124] {name: "Bob"} | | Node [222125] {name: "Bob"} | + -------------------------- + 2 rows of 46 ms   
     let  merge  Other Bob and see what happens.  
      neo4j-sh (?) $ Merge (p: person {name: "Bob"}); + -------------------------------------------- + | No data was returned, and nothing was changed. | + -------------------------------------------- + 2 MS Neo 4 J-Sh (?) $ Match (page: person {name: "bob"}) return page; + ---------------------- + + | P | + ---------------------- + + | Node [222124] {name: "Bob"} | | Node [222125] {name: "Bob"} | + -------------------------- + 2 rows 11 ms   
     Bob already exists, therefore  Merge  There was nothing here again inquiries, the same two Bobs are present. If there was no Bob in the database, then  MERGE  was treated as like  CREATE .

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