问将C#类转换为SQL表

EN

        var columnNames = GetColumnsToBeUpdated<T>().ToList();
        var columnTypes = GetColumnsTypesToBeUpdated<T>().ToList();


        var selects = columnNames.Select((t, i) => $"CAST(NULL as {columnTypes[i]}) AS [{t}]");

        var createsql = $@"
            SELECT {string.Join(", ", selects)}
            INTO SDE.[{tableName}]";

        using (var connection = new SqlConnection(_sdeConnectionString))
        {
            EsriServer.ExecuteNonQuery(connection, $"IF OBJECT_ID(N'SDE.[{tableName}]', N'U') IS NOT NULL " +
                                                   $"DROP TABLE SDE.[{tableName}]", null);
            EsriServer.ExecuteNonQuery(connection, createsql, null);
            EsriServer.ExecuteNonQuery(connection, $"TRUNCATE TABLE SDE.[{tableName}]", null);
        }

    private static string GetSqlDataType(Type type)
    {
        var name = type.Name;
        if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>))
        {
            name = type.GetGenericArguments()[0].Name;
        }

        switch (name)
        {
            case "Guid":
                return "uniqueidentifier";
            case "Boolean":
                return "bit";
            case "Byte":
                return "tinyint";
            case "Int16":
                return "smallint";
            case "Int32":
                return "int";
            case "Int64":
                return "bigint";
            case "Decimal":
                return "decimal(38,25)";
            case "Single":
                return "real";
            case "Double":
                return "float";
            case "DateTime":
                return "datetime";
            case "String":
            case "Char[]":
                return "nvarchar(max)";
            case "Char":
                return "nvarchar(1)";
            case "Byte[]":
                return "varbinary";
            case "Object":
                return "sql_variant";
            default:
                throw new ArgumentOutOfRangeException();
        }
    }

    private static IEnumerable<string> GetColumnsToBeUpdated<T>() where T : class, new()
    {
        var typeT = new T();
        var ps = typeT.GetType().GetProperties();
        var propertyNames = ps.Select(p => p.Name);

        return propertyNames.Except(GetColumnsToBeIgnored<T>());
    }

    private static IEnumerable<string> GetColumnsTypesToBeUpdated<T>() where T : class, new()
    {
        var typeT = new T();
        var ps = typeT.GetType().GetProperties();
        return ps.Select(p => p.PropertyType).Select(GetSqlDataType).ToList();
    }