HeapSort Biểu diễn Heap bằng mảng Thực hiện xây dựng Heap Trong khi mảng còn khác rỗng Lấy và thay thế phần tử gốc Xây dựng lại Heap
26 trang | Chia sẻ: vutrong32 | Ngày: 19/10/2018 | Lượt xem: 1380 | Lượt tải: 0
BCNF (Boyce-Codd Normal Form) Each normal form is strictly stronger than the previous one Every 2NF relation is in 1NF Every 3NF relation is in 2NF Every BCNF relation is in 3NF There exist relations that are in 3NF but not in BCNF The goal is to have each relation in BCNF (or 3NF)
62 trang | Chia sẻ: vutrong32 | Ngày: 19/10/2018 | Lượt xem: 1549 | Lượt tải: 0
FUNCTION Example: CREATE FUNCTION Contacts(@suppliers bit=0) RETURNS @Contacts TABLE (ContactName nvarchar(30), Phone nvarchar(24), ContactType nvarchar(15)) AS BEGIN INSERT @Contacts SELECT ContactName, Phone, 'Customer' FROM Customers INSERT @Contacts SELECT FirstName + ' ' + LastName, HomePhone, 'Employee' FROM Employees IF @Suppli...
31 trang | Chia sẻ: vutrong32 | Ngày: 19/10/2018 | Lượt xem: 1341 | Lượt tải: 0
Example: DECLARE MyCursor CURSOR FOR SELECT c.CustomerID,c.Companyname,c.contactname, o.OrderID,o.OrderDate FROM Customers c, Orders o WHERE c.CustomerID = o.CustomerID FOR UPDATE OPEN MyCursor DECLARE @cid VARCHAR( 8), @c VARCHAR( 80), @o INT, @od DATETIME, @cn VARCHAR( 80) FETCH NEXT FROM MyCursor INTO @cid, @c, @cn, @o, @od SELECT ...
20 trang | Chia sẻ: vutrong32 | Ngày: 19/10/2018 | Lượt xem: 1295 | Lượt tải: 0
Summary (continued) Data conversion, installation, documentation, and training follow programming and testing Installed and documented system is prerequisite for complete training Fully populated database needed to begin operation Support activities occur after system becomes operational and may continue for years to support user re...
9 trang | Chia sẻ: vutrong32 | Ngày: 19/10/2018 | Lượt xem: 1316 | Lượt tải: 0
Summary (continued) User interface is described with metaphors (desktop, document, dialog) Interface design guidelines and standards are available from many sources Dialog design starts with events, adds dialogs for integrity controls, user preferences, help, menus OO approach provides UML models to document dialog designs, includin...
7 trang | Chia sẻ: vutrong32 | Ngày: 19/10/2018 | Lượt xem: 1185 | Lượt tải: 0
Summary (continued) Object database stores data as collection of related objects and is developed from class diagram Objects can also be stored within RDBMS RDBMS cannot store methods RDBMS cannot directly represent inheritance Medium and larger information systems typically use multiple databases or database servers in various ge...
10 trang | Chia sẻ: vutrong32 | Ngày: 19/10/2018 | Lượt xem: 1678 | Lượt tải: 0
Summary (continued) Structure charts may be based on three-layer architecture Modules will be clearly identified by layer Structure chart may be decomposed if layers execute on multiple systems Structured design may also include: System flowcharts to show data movement Module pseudocode to describe internal logic of structure ch...
6 trang | Chia sẻ: vutrong32 | Ngày: 19/10/2018 | Lượt xem: 1473 | Lượt tải: 0
Summary (continued) Determine what alternatives are possible for developing solution Implementation alternatives include: Building system in-house Buying packaged or turnkey solution Contracting with developer to build it (outsource) Develop recommendations and present to management to make funding decisions
6 trang | Chia sẻ: vutrong32 | Ngày: 19/10/2018 | Lượt xem: 1235 | Lượt tải: 0
Summary (continued) Models from IE may supplement DFDs Process decomposition diagram (how processes on multiple DFD levels are related) Process dependency diagram (emphasizes interaction with stored entities) Location diagram (geographic where system used) Activity-location matrix (which processes are implemented at which location...
9 trang | Chia sẻ: vutrong32 | Ngày: 19/10/2018 | Lượt xem: 1558 | Lượt tải: 0