C＃中的条件异常中的数据类型不匹配

Question

i am making an application in which i insert a customer_Id with Double datatype in a Textbox1.

i use the customer_ID's value to access the database of respective customer_ID. i had converted the value of Textbox1 into Double datatype using

double cust_ID;  
Cust_ID=Convert.ToDouble(Textbox1.Text);  

and the query is

string s="select * from Customer where Customer_ID='"+Cust_ID+"'";

But yet i am getting the data type mismatch in criteria exception error.

Answer 1

Don't put the value in single quites. The following should work:

string s="select * from Customer where Customer_ID="+Cust_ID;

However, everyone else is also right - You shouldn't be using a double for an ID. IDs should always be an int or a long depending on how many items you expect.

Answer 2

ID使用整数而不是双精度数。