java - 2个表和2个值（变量）之间的sql语句Java

Question

我正在尝试执行以下操作，但它不接受它。

String sql_eco = "select * from orders where EmployeeID=" +e_ID + " and CustomerID ="' + cu_ID + "'";

从两个表和两个值（变量）中选择

Answer 1

尝试，假设CustomerID和EmployeeID都是Integer列类型

String sql_eco = "select * from orders where EmployeeID=" +e_ID + " and CustomerID =" + cu_ID;

Answer 2

尝试这个：

String sql_eco = "select * +
                  from orders +
                  where EmployeeID=" +e_ID + " and CustomerID ='" + cu_ID + "'";   
                                                               ^                                                                         

Answer 3

用这个。您已经放错了“ for CustomerId

String sql_eco = "select * from orders where EmployeeID=" +e_ID + " and CustomerID ='" + cu_ID + "'";

Answer 4

values variable u wanna say something like this?

String sql_eco = "select * +
                  from orders +
                  where 1=1 ";
if(e_ID  != null) {
 sql_eco += " AND EmployeeID=" +e_ID ;
}
if(cu_ID  != null){
 sql_eco  += " and CustomerID ='" + cu_ID + "'";  
}

to improve this code u can use stringbuilder/stringbuffer