python – 为什么“c.execute(…)”打破循环?

我正在尝试更改sqlite3文件中的一些数据,而我在
python和google-fu中不存在的知识让我最终得到了这段代码:

#!/usr/bin/python
# Filename : hello.py

from sqlite3 import *

conn = connect('database')

c = conn.cursor()

c.execute('select * from table limit 2')

for row in c:
    newname = row[1]
    newname = newname[:-3]+"hello"
    newdata = "UPDATE table SET name = '" + newname + "', originalPath = '' WHERE id = '" + str(row[0]) + "'"
    print row
    c.execute(newdata)
    conn.commit()
c.close()

它就像第一行的魅力一样,但由于某种原因它只运行一次循环(只有表中的第一行被修改).当我删除“c.execute(newdata)”时,它会循环遍历表中的前两行,就像它应该的那样.我如何使其工作?

最佳答案 这样做是因为只要你执行c.execute(newdata),光标就不再指向原始结果集了.我会这样做:

#!/usr/bin/python
# Filename : hello.py

from sqlite3 import *

conn = connect('database')

c = conn.cursor()

c.execute('select * from table limit 2')
result = c.fetchall()

for row in result:
    newname = row[1]
    newname = newname[:-3]+"hello"
    newdata = "UPDATE table SET name = '" + newname + "', originalPath = '' WHERE id = '" + str(row[0]) + "'"
    print row
    c.execute(newdata)
conn.commit()    
c.close()
conn.close()
点赞