Python 类型错误 : can only concatenate str (not "tuple") to str

Question

我正在尝试打印 SQL 输出的输出，如下所示:

dwh_cur.execute("""select count (*) from sales""")
var1 = dwh_cur.fetchone()
text = 'Total Sales is ' + var1

var1 = 100

预期输出:

Total Sales is 100

但我收到错误

TypeError: can only concatenate str (not "tuple") to str

Answer 1

dwh_cur.fetchone() 返回一条记录，该记录表示为 n 个元素的元组，

dwh_cur.execute("""select count (*) from sales""")
var1 = dwh_cur.fetchone()
text = 'Total Sales is {}'.format(var1[0])

可能会起作用，具体取决于查询返回的内容。