如何使用參數：在第SQL的Informix

Question

如何使用參數：在第SQL的Informix

StringBuilder cmdTxt = new StringBuilder(); 
cmdTxt.Append(" SELECT COUNT(emp_num) "); 
cmdTxt.Append(" FROM tbl1 WHERE year IS NULL AND calc_year = ? AND camp IN (,,,)"); 


       using (var myIfxCmd = new IfxCommand(cmdTxt.ToString(), con)) 
       { 
        myIfxCmd.CommandType = CommandType.Text; 
        myIfxCmd.Parameters.Add("calc_year", IfxType.Integer); 

        if (con.State == ConnectionState.Closed) 
        { 
         con.Open(); 
        } 
        myIfxCmd.Parameters[0].Value = calcYear; 

        res = int.Parse(myIfxCmd.ExecuteScalar().ToString()); 
       } 

我不知道如何處理參數傳遞到camp IN (,,,,)//Set of numbers

Answer 1

我有這樣的事情

IDbCommand cmd = connection.CreateCommand(); //connection has been instantiated 
cmd.CommandTimeout = connection.ConnectionTimeout; 

var query = @"SELECT COUNT(emp_num) 
       FROM tbl1 WHERE year IS NULL AND calc_year = @year AND camp IN ({0})"; 


cmd.Parameters.Add(new SqlParameter("@year", calcYear)); 
var sb = new StringBuilder(); 
//ids is a list/array of ids i want in the in clause 
for (int i = 0; i < ids.Count; i++) 
{ 
    sb.AppendFormat("@p{0},", i); 
    cmd.Parameters.Add(new SqlParameter("@p" + i, ids[i])); 
} 
if (sb.Length > 0) { sb.Length -= 1; } 
string cmdText = string.Format(query, sb.ToString()); 

cmd.CommandText = cmdText; 

cmd.Connection = connection; 
var reader = cmd.ExecuteReader();