如何從C＃中的ODBC獲取參數查詢＃

Question

如何在參數綁定後打印從C＃中的ODBC解析的查詢？ 這是示例代碼：

cmd.CommandText = "SELECT * from user WHERE id = ?"; 
cmd.Prepare(); 
cmd.Parameters.Add("@id", OdbcType.Int).Value = 2; 
OdbcDataReader reader = cmd.ExecuteReader(); 
string query = cmd.????; // Here i need a method for get a full query 

Answer 1

，默認情況下是不可能的，所以你可以寫一個擴展，與參數值替換paramater名。

例如：

internal class Program 
{ 
    private static void Main(string[] args) 
    { 
     OdbcConnection connection = new OdbcConnection(""); 
     OdbcCommand command = new OdbcCommand("SELECT * FROM Table WHERE Id = ? AND Column = ?", connection); 
     command.Parameters.Add("@id", OdbcType.Int).Value = 2; 
     command.Parameters.Add("@text", OdbcType.VarChar).Value = "test"; 

     string preparedSql = command.GetPreparedSql(); 
     // preparedSql = 
     Console.ReadLine(); 
    } 
} 

public static class OdbcExtensions 
{ 
    public static string GetPreparedSql(this OdbcCommand command) 
    { 
     string[] splitted = command.CommandText.Split(new[] {'?'}, StringSplitOptions.RemoveEmptyEntries); 
     StringBuilder builder = new StringBuilder(); 

     for (int i = 0; i < splitted.Length; i++) 
     { 
      builder.Append(splitted[i]); 

      OdbcParameter param = command.Parameters[i]; 

      switch (param.DbType) 
      { 
       case DbType.Boolean: 
        builder.Append(Convert.ToBoolean(param.Value) ? "1" : "0"); 
        break; 
       case DbType.AnsiString: 
        builder.AppendFormat("'{0}'", param.Value); 
        break; 
       default: 
        builder.Append(param.Value); 
        break; 
      } 

      builder.Append(" "); 
     } 

     return builder.ToString(); 
    } 
}