-2
Traceback (most recent call last):
File "run.py", line 1, in <module>
from blog import app
File "C:\Users\Administrator\Downloads\py2neo\neo4j-flask\blog\__init__.py", line 4, in <module>
graph.schema.create_uniqueness_constraint("User", "username")
File "C:\Users\Administrator\Downloads\py2neo\neo4j-flask\venv\lib\site-packages\py2neo\database\__init__.py", line 775, in create_uniqueness_constraint
{"property_keys": [property_key]})
File "C:\Users\Administrator\Downloads\py2neo\neo4j-flask\venv\lib\site-packages\py2neo\database\http.py", line 212, in post
raise_from(GraphError(message, **content), error)
File "C:\Users\Administrator\Downloads\py2neo\neo4j-flask\venv\lib\site-packages\py2neo\util.py", line 124, in raise_from
raise exception
py2neo.database.status.ConstraintViolationException: Constraint already exists: CONSTRAINT ON (user:User) ASSERT user.username IS UNIQUE
我認爲這個錯誤很明顯:你試圖在已經存在的db上添加一個約束。約束和索引只需要創建一次,它們不應該是任何反覆運行的腳本的一部分。即使您正在討論數據填充腳本,最好將索引和約束創建分離到其自己的腳本中,以便稍後嘗試將數據重新加載到相同的數據庫時不會影響它。 – InverseFalcon
那麼我需要做些什麼來解決它,刪除代碼graph.schema.create_uniqueness_constraint(「用戶」,「用戶名」)? –
我會這樣認爲的。該代碼不應出現在您打算運行多次的腳本中。 – InverseFalcon