Dapper Multi Mapping

[tundebabzy]

Thanks for this lovely application.

How does DapperQueryBuilder work with Dapper's multi mapping? Is it supported?

[Drizin]

Our CommandBuilder does not have facades for invoking Dapper Multi-mapper extensions directly, but you can combine CommandBuilder with Multi-mapper methods by explicitly passing CommandBuillder Sql and Parameters:

// DapperQueryBuilder CommandBuilder
var orderAndDetailsQuery = cn
    .QueryBuilder($@"
    SELECT * FROM Orders AS A 
    INNER JOIN OrderDetails AS B ON A.OrderID = B.OrderID
    /**where**/
    ORDER BY A.OrderId, B.OrderDetailId");
// Dynamic Filters
orderAndDetailsQuery.Where($"[ListPrice] <= {maxPrice}");
orderAndDetailsQuery.Where($"[Weight] <= {maxWeight}");
orderAndDetailsQuery.Where($"[Name] LIKE {search}");

// Dapper Multi-mapping extensions
var orderAndDetails = cn.Query<Order, OrderDetail, Order>(
        /* orderAndDetailsQuery.Sql contains [ListPrice] <= @p0 AND [Weight] <= @p1 etc... */
        sql: orderAndDetailsQuery.Sql,
        map: (order, orderDetail) =>
        {
            // whatever..
        },
        /* orderAndDetailsQuery.Parameters contains @p0, @p1 etc... */
        param: orderAndDetailsQuery.Parameters,
        splitOn: "OrderDetailID")
    .Distinct()
    .ToList();

To sum, instead of using DapperQueryBuilder CommandBuilder.Query<T> extensions (which invoke Dapper IDbConnection.Query<T>) you just invoke Dapper multimapper .Query<T1, T2, T3> directly, and use DapperQueryBuilder only for dynamically building your filters.

[tundebabzy]

Awesome. Thanks