参数化查询 - 多对象

Question

我发现question 这正是我想要做的。正确的答案似乎正是我想要的，但我想做一些事情，不要再次输入所有参数。

我有一个<Repere>，我已经为一个简单的参数化查询实现了一个函数：

public MySqlParameter[] GetListMySqlParams()
{
    return this.getListMySqlParams();
}
private MySqlParameter[] getListMySqlParams()
{
    MySqlParameter[] listParams = new MySqlParameter[]
    {
        new MySqlParameter("idContract", this.contrat.ID),
        new MySqlParameter("contractCode", this.Contrat.Code),
        new MySqlParameter("phaseName", this.fase.Name),
        new MySqlParameter("assemblyName", this.assembly.Name),
        new MySqlParameter("idPhase", this.fase.ID),
        new MySqlParameter("idAss", this.assembly.ID),
        new MySqlParameter("name", this.name),
        new MySqlParameter("priority", this.priority),
        new MySqlParameter("quantity", this.quantity),
        new MySqlParameter("totalQuantity", this.totalQuantity),
        new MySqlParameter("listOperations", this.listOperations.ConvertToString()),
        new MySqlParameter("material", this.geometry.Material),
        new MySqlParameter("drawing", this.geometry.Drawing),
        new MySqlParameter("profile", this.geometry.Profile.Name),
        new MySqlParameter("groupeProfil", this.geometry.GroupeProfil),
        new MySqlParameter("length", this.geometry.Length),
        new MySqlParameter("weightNet", this.geometry.WeightNet),
        new MySqlParameter("revision", this.geometry.Revision),
        new MySqlParameter("principal", this.principal),
        new MySqlParameter("unloadingZone", this.unloadingZone),
        new MySqlParameter("executionClass", this.executionClass),
        new MySqlParameter("category", this.category.ID),
        new MySqlParameter("description", this.description),
        new MySqlParameter("workingOrder", this.workingOrder),
        new MySqlParameter("isMountingPart", this.isMountingPart),
        new MySqlParameter("isPRS", this.isPRS),
        new MySqlParameter("idPRS", this.idPRS),
        new MySqlParameter("importOk",this.geometry.ImportOk),
    };
    return listParams;
}

我想要在那里使用解决方案，但不必再次输入所有参数（因为我想在几个对象和很多参数上这样做）。

这是我现在拥有的：

private void insertListReperes(List<Repere> listReperes)
{
    if (this.OpenConnection() == true)
    {
        using (this.connection)
        {
            string query = "INSERT INTO [vsteel].detail (ID_CONTRACT,NAME_CONTRACT,NAME_PHASE,NAME_ASS,ID_PHASE,ID_ASS,NAME,NAME_ORI,PRIORITY,QTE,QTE_TOT,OP," +
            "MATERIAL,DRAWING,PROFILE,GROUP_PROFILE,LENGTH,WEIGHT,REVISION,PRINCIPAL,UNLOADING_ZONE,EXECUTION_CLASS,ID_CATEGORY,DESCRIPTION,WORKING_ORDER," +
            "IS_MOUNTING_PART,IS_PRS,ID_PRS,IMPORT_OK) " +
            "VALUES (@idContract,@contractCode,@phaseName,@assemblyName,@idPhase,@idAss,@name,@name,@priority,@quantity,@totalQuantity,@listOperations," +
            "@material,@drawing,@profile,@groupeProfil,@length,@weightNet,@revision,@principal,@unloadingZone,@executionClass,@category,@description,@workingOrder," +
            "@isMountingPart,@isPRS,@idPRS,@importOk)";
            using (MySqlCommand cmd = new MySqlCommand(query.Replace("[vsteel].", ""), connection))
            {
                for(int i=0;i<listReperes.Count();i++)
                {
                    Repere repere = listReperes[i];
                    if(i==0)
                    {
                        MySqlParameter[] listParams = repere.GetListMySqlParams();
                        for (int j = 0; j < listParams.Count(); j++)
                        {
                            cmd.Parameters.Add(listParams[i]);
                        }
                        cmd.Prepare();
                        cmd.ExecuteNonQuery();
                    }
                    else
                    {
                        MySqlParameter[] listParams = repere.GetListMySqlParams();
                        for (int j = 0; j < listParams.Count(); j++)
                        {
                            cmd.Parameters[listParams[i].ParameterName].Value = listParams[i].Value;
                        }
                        cmd.ExecuteNonQuery();
                    }
                    repere.ID = cmd.LastInsertedId;
                }
            }
        }
    }
}

但是当我尝试在cmd.Parameters[listParams[i].ParameterName].Value = listParams[i].Value; 行设置参数时，它给了我参数已经定义的错误。 有没有办法在不复制所有参数名称的情况下做到这一点？

Answer 1

所以，我发现了问题。错误没有被抛出你所说的那一行；它在cmd.Parameters.Add 行上，这更有意义（源代码只会在添加期间抛出“已经存在”）

你写过：

cmd.Parameters.Add(listParams[i]);

你应该写：

cmd.Parameters.Add(listParams[j]);

通过使用[i]，您可以重复添加idContact 的参数，因为i 在j 循环的每次传递中始终为0

---

请注意，您在下一行也犯了同样的错误，因此您将 idContact 的值重复设置了 21 次

---

顺便说一句，我提到了一个名为 Dapper 的库（stackoverflow 将它用于所有数据访问），它可以让您的生活变得更简单。如果你写这样的代码：

using var connection = ... //get your connection here
var sql = "INSERT ... VALUES(@parameter, @names, @identical, @to, @your, @object, @properties); SELECT LAST_INSERT_IDENTITY()";
foreach(var v in itemstoinsert)
  v.id = connection.ExecuteScalar<int>(sql, v);

它应该是你所需要的一切......