psycopg2.ProgrammingError：关系“匹配”；不存在 [英] psycopg2.ProgrammingError: relation "matches" does not exist
问题描述
我正在尝试做一个最后的比赛项目，以大胆地介绍关系数据库课程。以下是项目说明的链接：
I'm trying to do a final 'tournament' project in intro to relational databases course by udacity. Here's a link to the project's description:
https://docs.google.com/document/d/16IgOm4XprTaKxAa8w02y028oBECOoB1EI1ReddADEeY/pub?embedded=true
我已经得到了一个名为Tournament.sql的文件，其中定义了数据库锦标赛以及两个表比赛和玩家：
I've got a file titled tournament.sql in which database 'tournament' and two tables 'matches' and 'players' are defined:
DROP DATABASE IF EXISTS tournament;
CREATE DATABASE tournament;
CREATE TABLE IF NOT EXISTS matches (
id SERIAL PRIMARY KEY,
player1 integer references players (id),
player2 integer references players (id)
);
CREATE TABLE IF NOT EXISTS players (
id SERIAL PRIMARY KEY,
name varchar(40)
);
我还在Tournament.py文件中定义了两个函数的主体deleteMatches和deletePlayers：
I also defined bodies of two functions deleteMatches and deletePlayers in tournament.py file:
import psycopg2
def connect():
"""Connect to the PostgreSQL database. Returns a database connection."""
return psycopg2.connect("dbname=tournament")
def deleteMatches():
"""Remove all the match records from the database."""
conn = connect()
c = conn.cursor()
c.execute("TRUNCATE TABLE matches;")
conn.commit()
conn.close()
def deletePlayers():
"""Remove all the player records from the database."""
conn = connect()
c = conn.cursor()
c.execute("TRUNCATE TABLE players;")
conn.commit()
conn.close()
还有一整个课程 tournament_test.py的作者预定义/预构建的python文件，可以执行该文件来检查锦标赛中是否所有必需的功能.py工作正常/做好工作。该文件'tournament_test.py'在虚拟机中从命令行执行，在我的情况下会产生以下错误：
There's one more python file predefined/prebuilt by the author of the whole course 'tournament_test.py', which can be executed to check if all required functions in tournament.py work fine/do their job. That file 'tournament_test.py' is executed in Virtual Machine from command line and in my case produces following error:
vagrant@vagrant-ubuntu-trusty-32:/vagrant/tournament$ python tournament_test.py
Traceback (most recent call last):
File "tournament_test.py", line 151, in
testCount()
File "tournament_test.py", line 17, in testCount
deleteMatches()
File "/vagrant/tournament/tournament.py", line 16, in deleteMatches
c.execute("TRUNCATE TABLE matches;")
psycopg2.ProgrammingError: relation "matches" does not exist
有人知道我的代码有什么问题吗？我开始失去耐心。我花了几个小时试图找出问题所在，并且可以找到任何有帮助的信息。这门课是如此糟糕，草率且不专业。我只是找不到合适的词来表达我的挫败感。
Does anyone know what's wrong with my code? I'm starting to lose patience. I've spent several hours trying to figure out, what's wrong and I can find any information that would be helpful. This course is so bad, sloppy and unprofessional. I just can't find right words to express my frustration.
推荐答案
您可能已经像我以前那样独自解决了这个问题
"You probably already solved this on your own like I had to, however if you are still searching or for anyone else who may come across this thread. I am also taking this course and came across this beginner problem.
这是用户，因此，如果您仍在搜索或正在寻找其他可能遇到此问题的人，我也在上这门课程，并且遇到了这个初学者问题。错误。我以错误的方式连接到无业游民和锦标赛数据库。
This was user error. I was connecting to vagrant and the tournament database in the wrong way.
登录无业游民后，我在正确的文件夹中访问正确的数据库，但方法错误
After logging into vagrant I was in the right folder accessing the right database but in the wrong method.
错误：
在无业游民中，我以无业游民身份进入psql并导入了文件。
Once in vagrant I went to psql as user vagrant and imported the file.
\i tournament.sql
然后我连接到数据库。
\c tournament
然后我退出psql运行文件并获取该关系不存在错误。
Then I was exiting psql to run the file and getting the relation does not exist error.
我需要再做一步。
FIX：
连接并登录数据库锦标赛后。我需要再次导入Tournament.sql文件。
Once connected and logged into the database tournament. I needed to import the tournament.sql file again.
这在实际数据库中创建了关系，而不仅仅是无聊的或者我以前在任何地方创建的关系。
That created the relations within the actual database and not just vagrant or wherever I was creating them before.
因此在命令Vagrant ssh
之后是从Vagrant获得的＃b $ b cd / vagrant / tournament /
so from Vagrant after the command Vagrant ssh # run these commands separately cd /vagrant/tournament/
psql
\i tournament.sql
\c tournament
\i tournament
#last check to verify your relations were created
\dt
\d (table or view)
这就是我所做的。该项目的其余部分很容易。我希望这对任何在这里搜索答案的人有所帮助。 我的问与答
That is what did it for me. The rest of the project was easy. I hope this helps anyone searching for the answer on here." My q&a
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