/// <summary>
/// Base DbConnection (SqlConnection) extension for Offset Paginated Batch Query capability.
///
/// Public Facade method to provide dynamically paginated results using Offset based paging/slicing.
///
/// NOTE: Since RepoDb supports only Batch querying using Page Number and Page Size -- it's less flexible
/// than pure Offset based paging which uses Skip/Take. Therefore, this logic provides an extension
/// of RepoDb core functionality; and if this is ever provided by the Core functionality
/// this facade will remain as a proxy to the core feature.
///
/// NOTE: Cursor Slice Querying is more flexible and works perfectly for Offset Based processing also so this
/// represents a facade around the Cursor Page slicing that maps between Skip/Take and Cursor paging paradigm.
///
/// NOTE: If the implementor needs further optimization then it's recommended to implement the optimized query
/// exactly as required; this should work well for many common use cases.
///
/// </summary>
/// <typeparam name="TEntity"></typeparam>
/// <param name="dbConnection">Extends the RepoDb BaseRepository abstraction</param>
/// <param name="orderBy"></param>
/// <param name="whereRawSql"></param>
/// <param name="pagingParams"></param>
/// <param name="tableName"></param>
/// <param name="hints"></param>
/// <param name="fields"></param>
/// <param name="commandTimeout"></param>
/// <param name="transaction"></param>
/// <param name="logTrace"></param>
/// <param name="cancellationToken"></param>
/// <returns>OffsetPageResults<TEntity></returns>
public static async Task <OffsetPageResults <TEntity> > GraphQLBatchSkipTakeQueryAsync <TEntity>(
this DbConnection dbConnection,
IEnumerable <OrderField> orderBy,
RawSqlWhere whereRawSql = null, //NOTE: This Overload allows cases where NO WHERE Filter is needed...
IRepoDbOffsetPagingParams pagingParams = default,
string tableName = null,
string hints = null,
IEnumerable <Field> fields = null,
int?commandTimeout = null,
IDbTransaction transaction = null,
Action <string> logTrace = null,
CancellationToken cancellationToken = default
)
//ALL entities retrieved and Mapped for Cursor Pagination must support IHaveCursor interface.
where TEntity : class
{
//Slice Querying is more flexible and works perfectly for Offset Based processing also so there is no
// need to maintain duplicated code for the less flexible paging approach since we can provide
// the simplified Offset Paging facade on top of the existing Slice Queries!
var sliceResults = await dbConnection.GraphQLBatchSliceQueryAsync <TEntity>(
orderBy : orderBy,
whereRawSql : whereRawSql,
pagingParams : ConvertOffsetParamsToCursorParams(pagingParams),
tableName : tableName,
hints : hints,
fields : fields,
commandTimeout : commandTimeout,
transaction : transaction,
logTrace : logTrace,
cancellationToken : cancellationToken
).ConfigureAwait(false);
//Map the Slice into the OffsetPageResults for simplified processing by calling code...
return(sliceResults.ToOffsetPageResults());;
}
private static IRepoDbCursorPagingParams ConvertOffsetParamsToCursorParams(IRepoDbOffsetPagingParams offsetParams)
{
return(new RepoDbCursorPagingParams(
after: offsetParams?.Skip,
first: offsetParams?.Take,
isTotalCountRequested: offsetParams?.IsTotalCountRequested ?? false
));
}
public async Task <IOffsetPageResults <ICharacter> > GetOffsetPagedCharactersAsync(
IEnumerable <Field> selectFields,
IEnumerable <OrderField> sortFields,
IRepoDbOffsetPagingParams pagingParams
)
{
await using var sqlConn = CreateConnection();
var offsetPageResults = await sqlConn.GraphQLBatchSkipTakeQueryAsync <CharacterDbModel>(
pagingParams : pagingParams,
orderBy : sortFields ?? DefaultCharacterSortFields,
fields : selectFields
);
var convertedPage = offsetPageResults.AsMappedType(r => MapDbModelToCharacterModel(r));
return(convertedPage);
}
/// <summary>
/// Base Repository extension for Offset Paginated Batch Query capability.
///
/// Public Facade method to provide dynamically paginated results using Offset based paging/slicing.
///
/// NOTE: Since RepoDb supports only Batch querying using Page Number and Page Size -- it's less flexible
/// than pure Offset based paging which uses Skip/Take. Therefore, this logic provides an extension
/// of RepoDb core functionality; and if this is ever provided by the Core functionality
/// this facade will remain as a proxy to the core feature.
///
/// NOTE: Cursor Slice Querying is more flexible and works perfectly for Offset Based processing also so this
/// represents a facade around the Cursor Page slicing that maps between Skip/Take and Cursor paging paradigm.
///
/// NOTE: If the implementor needs further optimization then it's recommended to implement the optimized query
/// exactly as required; this should work well for many common use cases.
///
/// </summary>
/// <typeparam name="TEntity"></typeparam>
/// <typeparam name="TDbConnection"></typeparam>
/// <param name="baseRepo">Extends the RepoDb BaseRepository abstraction</param>
/// <param name="orderBy"></param>
/// <param name="whereExpression"></param>
/// <param name="pagingParams"></param>
/// <param name="tableName"></param>
/// <param name="hints"></param>
/// <param name="fields"></param>
/// <param name="commandTimeout"></param>
/// <param name="transaction"></param>
/// <param name="logTrace"></param>
/// <param name="cancellationToken"></param>
/// <returns>OffsetPageResults<TEntity></returns>
public static async Task <OffsetPageResults <TEntity> > GraphQLBatchSkipTakeQueryAsync <TEntity, TDbConnection>(
this BaseRepository <TEntity, TDbConnection> baseRepo,
IEnumerable <OrderField> orderBy,
//NOTE: Expression is required to prevent Ambiguous Signatures
Expression <Func <TEntity, bool> > whereExpression,
IRepoDbOffsetPagingParams pagingParams = default,
string tableName = null,
string hints = null,
IEnumerable <Field> fields = null,
int?commandTimeout = null,
IDbTransaction transaction = null,
Action <string> logTrace = null,
CancellationToken cancellationToken = default
)
//ALL entities retrieved and Mapped for Cursor Pagination must support IHaveCursor interface.
where TEntity : class
where TDbConnection : DbConnection, new()
{
//Slice Querying is more flexible and works perfectly for Offset Based processing also so there is no
// need to maintain duplicated code for the less flexible paging approach since we can provide
// the simplified Offset Paging facade on top of the existing Slice Queries!
var sliceResults = await baseRepo.GraphQLBatchSliceQueryAsync <TEntity, TDbConnection>(
orderBy : orderBy,
whereExpression : whereExpression,
pagingParams : ConvertOffsetParamsToCursorParams(pagingParams),
tableName : tableName,
hints : hints,
fields : fields,
commandTimeout : commandTimeout,
transaction : transaction,
logTrace : logTrace,
cancellationToken : cancellationToken
).ConfigureAwait(false);
//Map the Slice into the OffsetPageResults for simplified processing by calling code...
return(sliceResults.ToOffsetPageResults());
}
