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不知道這是Npgsql或Dapper中的錯誤還是我做錯了。Npgsql + Dapper ExecuteReader
我想插入一個記錄數組並返回插入的行來獲取插入的ID。記錄被如
C#類
public class test
{
public int id { get; set; }
public string name { get; set; }
}
它被映射下表
// id is PK sequence
create table test (
id int,
name text
)
這裏一個Postgres陣列參數傳遞的插入碼
var sql = @"
with t as (
insert into public.test t (id, name)
select i.id, i.name
from unnest(@items) i left outer join t
on i.name = t.name
where i.id is null
returning *
)";
var items = new[]
{
new NpgsqlParameter("items", new []
{
new test() {name = "x"},
new test() {name = "y"},
}
};
// Not using Dapper for command exec as it doesn't support PG composite types
// Only using the RowParser
IList<T> result = new List<test>();
using (var connection = new NpgsqlConnection(...))
{
connection.MapComposite<test>("public.test");
using (NpgsqlCommand cmd = new NpgsqlCommand())
{
cmd.Connection = connection;
cmd.CommandType = CommandType.Text;
cmd.CommandText = sql;
cmd.Parameters.Add(parameters);
using (var reader = await cmd.ExecuteReaderAsync())
{
var hasRows = reader.HasRows; // true
var rowParser = reader.GetRowParser<test>(typeof(test)); // <== Dapper parser
result.Add(rowParser(reader)); // <== throws the exception below
}
}
}
result.Add(parser(reader))
投以下例外(IRowParser
是一個小巧玲瓏接口)
{System.InvalidOperationException: No row is available
at Npgsql.NpgsqlDataReader.CheckRow()
at Npgsql.NpgsqlDataReader.GetValue(Int32 ordinal)
任何想法這裏有什麼問題嗎?
是你的'rowParser'有價值嗎?你的'結果'是一類行嗎? –
'rowParser'是一個'IRowParser',它是一個Dapper接口。 'result'是一個'List' – ubi
'result'是什麼的列表? –