array binding with Npgsql

问题

Is there a way to do bulk operations with npgsql like with ODP.NET array binding feature ? I am aware of the Batching/Pipelining/multiple SQL statements in a single command (executing in a single roundtrip) but as far as I understand you can't use it in the same way, with different parameters for every statement. If it can be done, I would be happy if someone could provide an example how to convert the code below to Npgsql.

List<dto> listDTO; // list containing up to 1000 dtos

OraCommand = db.GetOracleCommand();
OraCommand.CommandText = "INSERT INTO TABLE (ID, FIELD1, FIELD2) VALUES (:ID, :FIELD1, :FIELD2)";

object[] FIELD1 = new object[listDTO.Count];
object[] FIELD2 = new object[listDTO.Count];

for (int i = 0; i <= listDTO.Count - 1; i++)
{
    ID[i] = listDTO.Id;
    FIELD1[i] = listDTO.Field1;
    FIELD2[i] = listDTO.Field2;                    
}
OraCommand.ArrayBindCount = listDTO.Count;

OraCommand.Parameters.Add(":ID", OracleDbType.Decimal, ID, System.Data.ParameterDirection.Input);
OraCommand.Parameters.Add(":FIELD1", OracleDbType.Varchar2, 10, FIELD1, System.Data.ParameterDirection.Input);
OraCommand.Parameters.Add(":FIELD2", OracleDbType.Varchar2, 32, FIELD2, System.Data.ParameterDirection.Input);

db.DoSqlPrepareCommand(OraCommand);

Edit: This is how I think it should best be done using Npgsql:

NpgsqlConnection conn = new NpgsqlConnection("connString");
conn.Open();    
NpgsqlCommand command = new NpgsqlCommand();    
string CommandText = "";

for (int i = 0; i <=5 ; i++)
{
    CommandText = CommandText + "INSERT INTO testtbl (id, field1) VALUES (@ID_" + i + " , @FIELD1_" + i + ");";

    command.Parameters.Add(new NpgsqlParameter("ID_" + i, i));
    command.Parameters.Add(new NpgsqlParameter("FIELD1_" + i, "FIELD1" + i));
}
command.CommandText = CommandText;
command.Connection = conn;
int result = command.ExecuteNonQuery();

回答1:

If what you're looking for is bulk insert of many rows, you should look at binary COPY - this is definitely the most efficient method.

Otherwise it's definitely possible to prepare your INSERT statement and then batch/pipeline its execution with different parameters in the same roundtrip. This will yield very good performance, although still not as good as binary COPY.

来源：https://stackoverflow.com/questions/44260860/array-binding-with-npgsql

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