如何在 IN 子句 sql informix 中使用参数

Posted 2023-04-19

【中文标题】如何在 IN 子句 sql informix 中使用参数

【英文标题】：How to use parameters in IN Clause sql informix

【发布时间】：2014-02-20 07:44:25

【问题描述】：

如何在IN子句sql informix中使用参数

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());
                

我不知道如何处理将参数传递给camp IN (,,,,)//Set of numbers

【参考方案1】：

我有这样的事情

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("@p0,", 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();