为什么这段代码不会将csv文件中的行放入sql表中？

Question

对于一个学校任务，我们需要在SQL中构建一个数据库，其中包含有关多位艺术家的信息。在作业的第一部分，我们需要将来自CSV文件的数据转储到SQL TABLE中。但是这似乎并不适用于我的代码。 TABLES在那里，代码运行时没有错误，但数据似乎没有放在TABLE中。我不知道是什么原因。

import sqlite3 
import csv 

artistsDb = sqlite3.connect("artists.sqlite3") 

artistsDbCursor = artistsDb.cursor() 
myQueryString = "CREATE TABLE artists (" +\ 
      "artistName CHAR (256)," +\ 
      "artistName CHAR (256)," +\ 
      "artistsDateOfBirth CHAR(256),"+\ 
      "artistYearsActive CHAR (256),"+\ 
      "artistsURL CHAR (256),"+\ 
      "artistsXNLFileName CHAR(256));" 
artistsDbCursor.execute ( myQueryString) 
artistsDb.commit 

myFile = open ("artists.csv") 
myReader = csv.reader (myFile, delimiter = ";") 

myQueryString = "INSERT INTO artists VALUES (?, NULL, NULL,NULL,NULL)" 
for myRowIterator in myReader: 
      myValues = myRowIterator 
      artistsDbCursor.execute(myQueryString, myValues,) 

Answer 1

由于乔恩已经克莱门特提到，你需要明确地承诺使用artistsDb.commit()交易（注意括号 - 他们都需要被调用的函数）的for循环之后。

也有你的脚本有不少可能的改进：采用多（三引号）的字符串

1. 使用上下文管理器的文件和数据库连接（以确保它们正常闭合）
2. 而不是连接（为便于阅读）
3. 避免无用的中介变量
4. 使用meaningfull名
二进制模式
5. 打开CSV文件（这是要求b Y代表正确操作csv模块）

下面是一个例子与最高分改写修正：

# XXX you had artistName defined twice, which shouldn't work... 
# I assume it was a copy-paste error and fixed it 
# Also you may want to add a unique key to your table, use VARCHAR 
# instead of CHAR, avoid 256 chars long fields when you don't need 
# that much, and use a date or datetime field for (resp.) dates and 
# datetime values. 

create_table_sql = """ 
CREATE TABLE artists (
    artistName CHAR (256), 
    artistsDateOfBirth CHAR(256), 
    artistYearsActive CHAR (256), 
    artistsURL CHAR (256), 
    artistsXNLFileName CHAR(256) 
    ); 
""" 

# You insert NULL values but have not declared the matching fields 
# as nullable. sqlite3 might accept this (sqlite3 accepts almost 
# anything) but any real SQL database will raise an error. 
insert_artist_sql = "INSERT INTO artists VALUES (?, NULL, NULL,NULL,NULL)" 

with sqlite3.connect("artists.sqlite3") as db: 
    cursor = db.cursor() 
    cursor.execute(create_table_sql) 
    db.commit() # this one is possibly useless but well 

    with open("artists.csv", "rb") as csvfile: 
     reader = csv.reader(csvfile, delimiter = ";") 
     for row in reader: 
      # 'row' IS the value already 
      cursor.execute(insert_artist_sql, row) 

     # and this was the missing part... 
     db.commit()