postgres bytea sql 在使用一个 sql 脚本 c# .net 插入和/或更新时出现参数错误

Question

我在将 bytea 流插入/更新到 postgres 表时遇到问题。

如果我单独尝试的话，插入和更新工作正常..

两者一起...发生错误()..

这是工作示例...

//INSERT ... is working! 
string MySqlInsertUpdateCommand = $"INSERT INTO ic_plc_streams(plcidx, stream, mytimestamp, 
streamlength) VALUES('{PlcIdx}',@stream,'{DateTime.Now}','{MyStream.Length}'); ";

//UPDATE ... is working!
string MySqlInsertUpdateCommand = $"UPDATE ic_plc_streams SET stream = @stream, 
mytimestamp='{DateTime.Now}', streamlength='{MyStream.Length}' WHERE plcidx='{PlcIdx}'; ";
<br>
//runs twice...
using (var command = new NpgsqlCommand(MySqlInsertUpdateCommand, conn))
{
    NpgsqlParameter param = command.CreateParameter();
    param.ParameterName = "@stream";
    param.NpgsqlDbType = NpgsqlTypes.NpgsqlDbType.Bytea;
    param.Value = MyStream;
    command.Parameters.Add(param);
    conn.Open();
    command.ExecuteNonQuery();
}


<br>
//not WORKING



//insert or update!
string MySqlInsertUpdateCommand = $"do $$ begin UPDATE ic_plc_streams SET stream = @stream,         
mytimestamp='{DateTime.Now}', streamlength='{MyStream.Length}' WHERE plcidx='{PlcIdx}'; " +
$"if not found Then INSERT INTO ic_plc_streams(plcidx, stream, mytimestamp, streamlength)     
VALUES('{PlcIdx}',@stream,'{DateTime.Now}','{MyStream.Length}'); " +
$"End if; end$$";




using (var command = new NpgsqlCommand(MySqlInsertUpdateCommand, conn))
{
    NpgsqlParameter param = command.CreateParameter();
    param.ParameterName = "@stream";
    param.NpgsqlDbType = NpgsqlTypes.NpgsqlDbType.Bytea;
    param.Value = MyStream;
    command.Parameters.Add(param);
    conn.Open();
    command.ExecuteNonQuery();
}

Errormessage: (postgres 9.4)
{"42883: Operator existiert nicht: @ bytea"}
(UPDATE ic_plc_streams SET stream = @stream, mytimestamp='23.10.2023 14:27:54', streamlength='28' WHERE plcidx='0'
)
Kein Operator stimmt mit dem angegebenen Namen und den Argumenttypen überein. Sie müssen möglicherweise ausdrückliche Typumwandlungen hinzufügen.

也许有人可以帮忙...？

Answer 1

DO

块中没有参数。您可以创建一个真实的函数或过程。您还可以编写一个 

upsert

 语句来插入或更新记录。