Ios 未知逃逸序列'\x20'；

我已经创建了这个代码

NSString *insertSQL = [NSString stringWithFormat:@"Update Expense_Group set Expense_sum = Expense_sum-\%@\ where Expense_Type_Id = \"%@\"",strExpAmount,current_Expense_TypeId];

现在，我得到了这个警告“未知转义序列'\x20'”

您只需要“

\

”转义该“

stringWithFormat:

”调用中的引号

这可以解决%@之前不需要转义序列的问题

NSString *insertSQL = [NSString stringWithFormat:@"Update Expense_Group set Expense_sum = Expense_sum-'%@' where Expense_Type_Id = '%@'",strExpAmount,current_Expense_TypeId];

NSString *insertSQL = [NSString stringWithFormat:@"Update Expense_Group set Expense_sum = Expense_sum-'%@' where Expense_Type_Id = '%@'",strExpAmount,current_Expense_TypeId];