+ Types of Data IST210 Class Lecture

+ What kind of data do you have? Class Schedules Contacts Names Phone Numbers Address Food Specials Movies, Music Collect

+ How do you store data? Paper Post-it Notes Excel iTunes Address Book

+ List Activity Get in groups of 3 people Nominate one person as the scribe, and have them type your list Make a list of all the data you store and how it is stored

+ Problems with Lists Redundancy - In a list, each row is intended to stand on its own. As a result, the same information may be entered several times. For Example: A list of Projects may include the Project Manager’s Name, ID, and Phone Extension. If a particular person is managing 10 projects, his/her information would have to be entered 10 times.

+ Problems with Lists Multiple Themes - In a list, each row may contain information on more than one theme. As a result, needed information may appear in the lists only if information on other themes is also present. For Example: A list of Projects may include Project Manager information (Name, ID, and Phone Extension) and Project information (Name, ID, StartDate, Budget) in the same row

+ List Modification Issues Redundancy and multiple themes create modification problems: Deletion problems Update problems Insertion problems

+ List Modification Issues

+ Types of Data Objects that contain data have an associated data type that defines the kind of data. The following objects have data types: Columns in tables and views. Parameters in stored procedures. Variables. Transact-SQL functions that return one or more data values of a specific data type. Stored procedures that have a return code, which always has an integer data type.

+ Types of Data Assigning a data type to an object defines four attributes of the object: The kind of data contained by the object. The length or size of the stored value. The precision of the number (numeric data types only). The scale of the number (numeric data types only).