Python 2.7.8：TypeError：％d format：需要一个数字，而不是元组

Question

当我写简单时：

sqli = ("SELECT SUM(obtained) FROM stobt  WHERE stid = %d " ) %(row2)

没有错误并打印，

但是当我写道：

sqli = ("SELECT SUM(obtained) FROM stobt  WHERE stid = %d and subject='%s'" ) %(row2,sub)

给了我一个让我生病的错误：

错误：

TypeError: %d format: a number is required, not tuple

更多这里是我的数据库：

Answer 1

您的问题必然会创建查询字符串，并且与真实数据库（尚未）无关。

如果row2是一个整数而sub是一个字符串，那么它适用于我：

>>> row2 = 12
>>> "SELECT SUM(obtained) FROM stobt  WHERE stid = %d " % (row2)
'SELECT SUM(obtained) FROM stobt  WHERE stid = 12 '
>>> sub = "subject"
>>> "SELECT SUM(obtained) FROM stobt  WHERE stid = %d and subject='%s'" % (row2, sub)
"SELECT SUM(obtained) FROM stobt  WHERE stid = 12 and subject='subject'"
>>> ("SELECT SUM(obtained) FROM stobt  WHERE stid = %d and subject='%s'") % (row2, sub)
"SELECT SUM(obtained) FROM stobt  WHERE stid = 12 and subject='subject'"
>>> type(row2)
int

请确保您没有更改row2的值。