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CIS162AD. Databases 14_databases.ppt. Overview of Topics. Relational Database Terminology ADO.Net Binding data. Relational Databases. Most data is now stored in relational database management systems (DBMS or RDBMS).
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CIS162AD Databases 14_databases.ppt
Overview of Topics • Relational Database Terminology • ADO.Net • Binding data
Relational Databases • Most data is now stored in relational database management systems (DBMS or RDBMS). • There are various vendors to choose form:Oracle, MS SqlServer, Sybase, IBM DB2, etc. • Visual Studio is usually used to develop applications that store data in Microsoft SqlServer. • In this class we will use MS Access, due to SqlServer’s installation requirements. • Those of you familiar with Access know that it has a built-in form and report designer. However, keep in mind that we would normally be accessing a database stored in SqlServer, which does not have built-in tools.
Database Terminology • A database is made up of one or more related tables. • Conceptually a table is made up of rows and columns (2D Array). • Each row represents the data for one record(a person, inventory item, course information). • Each column (field) is a data element (name, address, city, state, zip). • Tables have a Primary Key Field to uniquely identify each record(Id number, part number, account number). • Relationships between various tables can be defined. • A DBMS stores everything (tables, columns, relationships, etc.) about the database in system tables. • System and data tables are usually stored in one file (CSMail.mbd).
SQL – Structured Query Language • SQL is pronounced sequel. • SQL – Structured Query Language – Basic set of commands that are common in all DBMS. • DBMS vendors may add additional commands. • SQL commands are usually processed against a record set. • Select name, address From customer where zip = “85202”; • Delete From customer where zip = “85202”All rows matching the criteria would be selected or deleted. • Record set commands are very powerful. • We’ll usually want to qualified a command by specifying a customer id or other unique identifier using the Where clause.
An Access Table Columns Row
Accessing a Database – ADO.Net • Use ActiveX Data Objects (ADO) • An Access database uses the following objects: • OleDbConnection – connection tool establishes a link to a data source. • OleDbDataAdapter – data adapter handles retrieving and updating the data and creates a Dataset. • Dataset – bind columns in the Dataset to controls (textbox, listbox) by setting the DataBinding property. • Use the Fill method of the data adapter to load the data into the dataset, daCustomer.Fill(dsCustomer1);The Fill method is usually placed in the form load event.
Web Form Data Source Connection Data Adapter Dataset Windows Form Specific data file Connects to data source Handles data transfer and provides data for dataset; uses SQL Actual data stored in memory; can contain multiple tables Bounded controls display data Accessing and Presenting Data
Data Binding • Complex Binding • Connect more than one data element to a control. • DataGridView uses complex binding because several columns from the table are displayed in the same control. • Simple Binding • Connect one data element to a control. • Connect a textbox to the name column (etc.) • May use Data Bindings property and select the column from the database that should be displayed in control. • Later we’ll build a form using Labels and Textboxes.
Completing CS13 • See assignment sheet for details.
Summary • Relational Database Terminology • ADO.Net • Binding data