MySQL Reader立即关闭

我有一种递归填充列表的方法。首先，它选择“父项”，然后使用外键选择它可能具有的所有子项。它可以很好地选择“父项”项目，但是当它开始选择子项时，即Reader无缘无故关闭。

我已经在调试器中对其进行了跟踪，没有理由可以看到它即将关闭。搜索参数有效，搜索返回项（我手动检查过），并且处于Reader活动状态。但是由于某种原因，它一打开就关闭，没有任何错误。

• 连接字符串有效
• 读者有效
• 搜索参数有效
• 该命令返回结果（我专门测试了这一WHERE 1 = 1 AND SE.ParentSE = 4;";结果-超过10个结果）

我不知道这是怎么回事？

try
{
    using (MySqlConnection connection = new MySqlConnection(GetConnectionString()))
    {
        connection.Open();

        using (MySqlCommand command = connection.CreateCommand())
        {
            command.CommandText = @"SELECT 
                                    SE.SEId,
                                    SE.Name,
                                    SE.Status,
                                    SE.Description,
                                    SE.ParentME AS ParentMEId,
                                    SE.ParentSE AS ParentSEId,
                                    SE.Comments AS Comments,
                                    SE.Removed AS Removed,
                                    SE.SupplierId AS SupplierId,
                                    TC.TerminalCount AS TerminalCount,
                                    SE2.Name AS ParentSE,
                                    ME.EquipmentNumber AS ParentME,
                                    D.DSId AS DataSheet,
                                    D.DSType AS DataSheetType,
                                    C.Code AS EquipmentType,
                                    C.Description AS TypeDescription,
                                    C.CodeType AS TypeDiscipline,
                                    SE.EquipmentType AS EquipTypeId,
                                    SE3.SEId AS SE3Id,
                                    SE4.SEId AS SE4Id,
                                    SE5.SEId AS SE5Id,
                                    SE6.SEId AS SE6Id,
                                    SE2.ParentME AS ME2Id,
                                    SE3.ParentME AS ME3Id,
                                    SE4.ParentME AS ME4Id,
                                    SE5.ParentME AS ME5Id,
                                    SE6.ParentME AS ME6Id,
                                    PAC.UDCId AS AreaCodeId,
                                    PAC.Code AS AreaCode,
                                    PAC.Description AS AreaCodeDescription
                                FROM SubEquipment SE
                                LEFT  JOIN DataSheet D ON SE.SEId = D.SEId
                                LEFT JOIN (SELECT SEId, COUNT(*) as TerminalCount FROM Terminal GROUP BY SEId) TC ON SE.SEId = TC.SEId
                                LEFT JOIN SubEquipment SE2 ON SE.ParentSE = SE2.SEId
                                LEFT JOIN MajorEquipment ME ON SE.ParentME = ME.MEId
                                LEFT JOIN UserDefinedCode C ON C.UDCId = SE.EquipmentType
                                LEFT JOIN SubEquipment SE3 ON SE2.ParentSE = SE3.SEId
                                LEFT JOIN SubEquipment SE4 ON SE3.ParentSE = SE4.SEId
                                LEFT JOIN SubEquipment SE5 ON SE4.ParentSE = SE5.SEId
                                LEFT JOIN SubEquipment SE6 ON SE5.ParentSE = SE6.SEId
                                INNER JOIN MajorParentage MP ON SE.SEId = MP.SEId
                                INNER JOIN MajorEquipment MEU ON MP.MEId = MEU.MEId
                                INNER JOIN UserDefinedCode PAC ON MEU.PACId = PAC.UDCId
                                LEFT JOIN ComponentStatus CS1 ON CS1.StatusName = SE.Status
                                WHERE 1 = 1"
                                // " AND SE.ParentSE = @SEParentId"                                    
                                // @SEParentId = 4
                                + parentSearch
                                + ";";

            command.Parameters.AddWithValue("@PACId", areaCodeId);
            command.Parameters.AddWithValue("@AreaCode", areaCode.Cipher());
            command.Parameters.AddWithValue("@ETId", equipmentTypeId);
            command.Parameters.AddWithValue("@EquipmentType", equipmentType.Cipher());
            command.Parameters.AddWithValue("@EquipmentNumber", equipmentNumber.Cipher());
            command.Parameters.AddWithValue("@Description", description.Cipher());
            command.Parameters.AddWithValue("@Comments", comments.Cipher());
            command.Parameters.AddWithValue("@TypeDiscipline", typeDiscipline);
            command.Parameters.AddWithValue("@MEParentId", parentMEId);
            command.Parameters.AddWithValue("@MEParent", parentMENumber.Cipher());
            command.Parameters.AddWithValue("@SEParentId", parentSEId);
            command.Parameters.AddWithValue("@SEParent", parentSENumber.Cipher());
            command.Parameters.AddWithValue("@SEId", excludeSEId);
            command.Parameters.AddWithValue("@Status", status.Cipher());

            using (MySqlDataReader reader = command.ExecuteReader())
            {
                // Read all the results and populate a model with them.
                while (reader.Read())
                {
                    // Do stuff...
                }
                // Finished reading the results
                if (!reader.IsClosed)
                    reader.Close();
            }
        }

        // Finished with the connection
        if (connection.State == System.Data.ConnectionState.Open)
            connection.Close();
    }
}
catch (MySqlException e)
{
    ShowMySQLError(e, 4417);
}