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Accessing Databases By Brian Hall Database History Originally paper and books Drawers and drawers of paper and ink Difficult to have a back up copy If building destroyed then information destroyed Pain in the neck to transfer information across miles This can be very bad History (contd.) First ‘relational’ products appeared late 70’s early 80’s Relational model basically means that the information is represented in rows and columns (to the user) Relational Example FName LName Age Classification John Doe 19 Sophomore Jane Doe 22 Senior How does SQL tie in? SQL is the language that helps manipulate, design, and access your database. With it you can: SELECT INSERT UPDATE DELETE information Development Languages 1. 2. 3. Visual Basic 6.0 PHP COBOL Visual Basic 6.0 Pros Much support available Widely used Many communities Cons Runs solely on Microsoft platforms VB6 Connection Code Dim Database as DAO.Database Dim Recordset as DAO.Recordset Set Database = OpenDatabase(<databaselocation>) StrSql = "SELECT Stu_FName ,Stu_LName FROM Student" Set R1 = Database.OpenRecordset(StrSql) Do Until Recordset.EOF cmbName.AddItem (Recordset!Stu_FName + " " +_ Recordset!Stu_LName) Recordset.MoveNext Loop PHP Pros Cons Fast and efficient VERY loosely typed Runs on server not on Constantly changing client machine Not platform specific Not browser specific Small learning curve PHP Connection Code <html> <body> <?php $db = mysql_connect("localhost", "root"); mysql_select_db("mydb",$db); $result = mysql_query("SELECT * FROM employees",$db); echo "<table border=1>\n"; echo "<tr><td>Name</td><td>Position</tr>\n"; while ($myrow = mysql_fetch_row($result)) { printf("<tr><td>%s %s</td><td>%s</td></tr>\n", $myrow[1], $myrow[2], $myrow[3]); } echo "</table>\n"; ?> </body> </html> COBOL Pros Generally Easy to use Easy to teach Text parse and test functions built in Cons Verbose language Cannot directly define data types COBOL Connection Code Need to include EXEC SQL INCLUDE SQLCA END-EXEC. And the compiler will automatically add… THIS 01 SQLCA. 05 SQLCAID PIC X(8). 05 SQLCABC PIC S9(9) BINARY. 05 SQLCODE PIC S9(9) BINARY. 05 SQLERRM. 49 SQLERRML PIC S9(4) BINARY. 49 SQLERRMC PIC X(70). 05 SQLERRP PIC X(8). 05 SQLERRD OCCURS 6 TIMES PIC S9(9) BINARY. 05 SQLWARN. 10 SQLWARN0 PIC X. 10 SQLWARN1 PIC X. 10 SQLWARN2 PIC X. 10 SQLWARN3 PIC X. 10 SQLWARN4 PIC X. 10 SQLWARN5 PIC X. 10 SQLWARN6 PIC X. 10 SQLWARN7 PIC X. 10 SQLWARN8 PIC X. 10 SQLWARN9 PIC X. 10 SQLWARNA PIC X. 05 SQLSTATE PIC X(5). Contributions Research Term Paper (Rough/Final) Brian Hall Presentation (Rough/Final) Brian Hall Brian Hall Staying Up All Night to finish this dang thing…. Brian Future Endeavors Research further into each language and actual language connection strings (more in depth) Research further into SQL and built in functionality Research further into local and server based server suppliers (DB2, MySQL, SQL2000, etc.) Bibliography Database Book “PHP/MySQL Tutorial”; Graeme Merall; http://webmonkey.wired.com/webmonkey/programming/php/tutorials/tutorial 4.html “PHP Pros and Cons”; http://c2.com/cgi/wiki?PhpProsAndCons “The Cobol Language”; http://www.cs.vu.nl/~eliens/documents/libero/lrlang6.htm “Defining the SQL Communications Area in COBOL applications that use SQL”; http://publib.boulder.ibm.com/html/as400/v4r5/ic2924/index.htm?info/db2/rz ajpmst43.htm “An Introduction to Database Systems”, 8th Ed.; CJ Date; © 2004 Pearson Education, Inc.