Databases and Data Modeling for Accounting Information Systems Databases and Data Modeling for Accounting Information Systems

Databases and Data Modeling for Accounting Information Systems Databases and Data Modeling for Accounting Information Systems

Normalization Flat files are files with no sequence or order to them.Flat files are files with no sequence or order to them. Flat files make it almost impossible to find a particular record easily or use file data productively.Flat files make it almost impossible to find a particular record easily or use file data productively. Normalization is a process of examining and arranging file data in a way that enables designers to avoid problems when these files are used or modified later.Normalization is a process of examining and arranging file data in a way that enables designers to avoid problems when these files are used or modified later. Databases and Data Modeling for Accounting Information Systems

Example: Un-normalized Parking Ticket Data (0 Normal Form) Databases and Data Modeling for Accounting Information Systems Social Security Number Last Name First Name Phone No. LicenseStateLicenseNumber Ticket No DateCodeFine CurryDorothy(916) CA123MCD /15/98A$ /16/98B$ /12/98B$ FongMay(916) CA253DAL /23/98C$ /05/98A$10

Databases and Data Modeling for Accounting Information Systems First Normal Form A database is in first normal form (1NF) if all the records attributes (data fields) are well defined and the information can thus be stored in a flat file.Example: Social Security Number Last Name First Name Phone No. LicenseStateLicenseNumber Ticket No DateCodeFine CurryDorothy(916) CA123MCD /15/98A$ CurryDorothy(916) CA123MCD /16/98B$ CurryDorothy(916) CA123MCD /12/98B$ FongMay(916) CA253DAL /23/98C$ FongMay(916) CA253DAL /05/98A$10

Second Normal Form Databases and Data Modeling for Accounting Information Systems * A database is in second normal form (2NF) if it is in first normal form and all the data items in each record depend on the records primary record key. * This approach results in a more efficient design and eliminates much of the first files data.

Example: Second Normal Form Databases and Data Modeling for Accounting Information Systems Car Registration File Social Security Number Last Name First Name Phone No. License Plate State Number CurryDorothy(916) CA123MCD FongMay(916) CA253DAL Ticket File Ticket No DateCodeFine [License Plate] State Number /15/98A$10CA123MCD /16/98B$20CA123MCD /12/98B$20CA123MCD /23/98C$50CA253DAL /05/98A$10CA253DAL

Third Normal Form Databases and Data Modeling for Accounting Information Systems Our goal is to create a database that is minimally in third normal form (3NF). A database is in third normal form if it is in second normal form and contains no transitive dependencies - i.e., no relationships in which data field A determines data field B.

Third Normal Form Databases and Data Modeling for Accounting Information Systems Car Registration File Social Security Number Last Name First Name Phone No. License Plate State Number CurryDorothy(916) CA123MCD FongMay(916) CA253DAL Ticket File Ticket No Date[Code][License Plate] State Number /15/98ACA123MCD /16/98BCA123MCD /12/98BCA123MCD /23/98CCA253DAL /05/98ACA253DAL Violation Code File CodeFineExplanationA$10 Meter expired B$20 Parking in no- parking zone C$50 No parking sticker

Database Management Systems Databases and Data Modeling for Accounting Information Systems A database management systems (DBMS) is a set of separate computer programs that enable users to create, and modify database information more efficiently. The data definition language (DDL) of a DBMS enables users to define the record structure of any particular database table. Data Sets A,B,C, D,E,F Database Management System (DBMS) Application Program 1 Application Program 3 Application Program 2 Users

EMP # DEPT # EMP NAME JOB CODE JOB TITLE LOCATION HOURS WORKED 12001Abriel1Accountant New Orleans Abrial1Accountant Los Angeles Bayer1Accountant New Orleans Bayer1Accountant Los Angeles Bayer1Accountant New York Boudreaux2Supervisor Los Angeles Baudreaux2Supervisor New York Wolbrette3Manager New Orleans Scanlon2Supervisor New York Richards1Accountant New Orleans Richards1Accountant Los Angeles Richards1Accountant New York Daly1Accountant New Orleans 16 Data Normalization for Relational DBMS Databases and Data Modeling for Accounting Information Systems

Database Management Systems Databases and Data Modeling for Accounting Information Systems

Database Management Systems

Databases and Data Modeling for Accounting Information Systems

Database Management Systems Databases and Data Modeling for Accounting Information Systems

User Views: Schemas and Subschemas Databases and Data Modeling for Accounting Information Systems The totality of information in a database and the relationships of its tables (records) is called the databaseschema.The totality of information in a database and the relationships of its tables (records) is called the database schema. The databaseschemais a map or plan of the entire database.The database schema is a map or plan of the entire database. Any particular user or application program will be interested in only a subset of the schema, called thesubschemaAny particular user or application program will be interested in only a subset of the schema, called the subschema. A database must be flexible enough to satisfy the subschema uses required.A database must be flexible enough to satisfy the subschema uses required.

Example: Schemas and Subschemas Schema for aCustomer RecordSchema for a Customer Record –ACCOUNT-NUMBER –CUSTOMER-NAME –CUSTOMER ADDRESS –SALES-DIVISION –CREDIT-LIMIT –BALANCE –CREDIT-TERMS –TOT-YEARS-SALE –DATE-RECENT-SALE Subschema for aSales Order Entry ApplicationSubschema for a Sales Order Entry Application –ACCOUNT-NUMBER –CUSTOMER-NAME –CUSTOMER-ADDRESS –CREDIT-LIMIT –BALANCE –CREDIT-TERMS Subschema for aSales Analysis ApplicationSubschema for a Sales Analysis Application –ACCOUNT-NUMBER –CUSTOMER-NAME –CUSTOMER-ADDRESS –SALES-DIVISION –TOT-YEARS-SALES Databases and Data Modeling for Accounting Information Systems

Query Language (DML) Databases and Data Modeling for Accounting Information Systems The data manipulation language (DML) enables users to perform tasks such as querying, changing records and deleting records. structured query language (SQL).Many relational databases support structured query language (SQL).

Query Language (DML) Databases and Data Modeling for Accounting Information Systems

The SELECT Operation Query language commend: SELECT ABBOTT OF EMPLOYEE DISPLAY EMP NAME AND JOB EMP# EMP NAME JOB 11 Smith, A Garcia, B Wong, C. 3 29Riley,D.4 33 OHara, E Weiss, F Abbott, G Powski, H. 4 SELECT Display: EMP NAME JOB Abbott,G. 3 The PROJECT Operation Query language commend: PROJECT EMP NO AND PAY RATE OF PAY-RATEEMP#HIREDATAPAYRATE1119X X X X X X X X EMP#PAYRATE Operate Relational Database Using Query Language (DML) PROJECT

Operate Relational Database Using Query Language (DML) The JOIN Operation Query language commend: JOIN EMPLOYEE WITH JOB/DEPT DISPLAY DEPT AND NAME EMP# EMP NAME JOB 11Smith, A.4 14Garcia, B.2 27Wong, C.3 29Riley,D.4 33OHara, E.1 36Weiss, F.1 41Abbott, G.3 45Powski, H.4 JOBDEPT EMP#EMP NAME JOBDEPT11 Smith, A Garcia, B Wong, C Riley,D OHara, E Weiss, F Abbott, G Powski, H. 42 JOIN Databases and Data Modeling for Accounting Information Systems

Online Analytical Processing Complex multidimensional data analysis performed on database information is called online analytical processing (OLAP). Databases and Data Modeling for Accounting Information Systems Object-Oriented and Multimedia Databases The object-oriented database (OODB) The object-oriented database (OODB) is a type of database that contains both the text data of traditional databases, plus Information about the set of actions that can be taken on the data fields.

Data Warehouse A data warehouse pools data from separate applications into a large common body of information.A data warehouse pools data from separate applications into a large common body of information. Advantages of data warehouses:Advantages of data warehouses: 1.Data are clean of errors and defined uniformly. 2.Data are stored in several databases, not just one. 3.Data Warehouses span a longer time horizon than the companys transaction systems. 4.The data relations are optimized for answering complex questions 4.The data relations are optimized for answering complex questions. Databases and Data Modeling for Accounting Information Systems

Thank you Databases and Data Modeling for Accounting Information Systems