Python 从列表更新sqlite3数据库
“我的表”中的列如下所示:Python 从列表更新sqlite3数据库,python,list,sqlite,Python,List,Sqlite,“我的表”中的列如下所示: for i in Name1: c.execute("SELECT * FROM Mytable WHERE Number1 IS NULL") if Name1 is List3: c.execute("INSERT INTO Mytable (Number1, Number2)" " VALUES (?, ?)", (List5[i], List6[i])) elif Name2 is List4: c.ex
for i in Name1:
c.execute("SELECT * FROM Mytable WHERE Number1 IS NULL")
if Name1 is List3:
c.execute("INSERT INTO Mytable (Number1, Number2)" " VALUES (?, ?)",
(List5[i], List6[i]))
elif Name2 is List4:
c.execute("INSERT INTO Mytable (Number1, Number2)" " VALUES (?, ?)",
(List5[i], List6[i]))
名称1 |名称2 |重量|高度|编号1 |编号2
有些Number1和Number2列是空的,我只想更新空行。为此,我有6个列表:
List1 contains the values in Name1, in the same order
List2 contains the values in Name2, in the same order
List3 contains the values in Name1, but in a different order
List4 contains the values in Name2, but in the same order as List3
列表5和6分别包含要插入到Number1和Number2中的值,其顺序与列表3和4相同
所以我想做的是:
for i in Name1:
c.execute("SELECT * FROM Mytable WHERE Number1 IS NULL")
if Name1 is List3:
c.execute("INSERT INTO Mytable (Number1, Number2)" " VALUES (?, ?)",
(List5[i], List6[i]))
elif Name2 is List4:
c.execute("INSERT INTO Mytable (Number1, Number2)" " VALUES (?, ?)",
(List5[i], List6[i]))
但是,当我运行它时,它会向表中添加行,但不会为Number1或Number2添加任何值。我哪里做错了
我哪里做错了
可能在这里:
if Name1 is List3:
[...]
elif Name2 is List4:
是
关键字测试,这不是您想要的。在这里,即使是平等测试也帮不了你,因为两个列表中的顺序是不同的
>>> a = ["a", "b", "c"]
>>> b = a
>>> a is b
True
>>> a = ["a", "b", "c"]
>>> b = ["a", "b", "c"]
>>> a is b
False
>>> a == b
True
>>> b = ["b", "c", "a"]
>>> a == b
False
由此产生的行为是没有执行if
分支。为了实现目标,您需要测试两个列表是否包含相同的成员:
但是,您的问题不清楚确切的条件:Name1/List3和Name2/List4应该包含完全相同的成员,还是一个成员包含在另一个成员中就足够了?你也许能自己想出解决办法;如果不是,我建议你就这个具体问题再问一个问题