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CIS 375—Web App Dev II
ADO I
2
Introduction ADO (________ Data Objects) is a Microsoft
technology for accessing data in a database. ADO is automatically installed with _____. The common way to access a database from
within an ASP page is to: Create an ADO ___________ to a database Open the database connection Create an ADO __________ Open the recordset Extract the data you need from the recordset Close the recordset Close the connection
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Database Connections Before a DB can be accessed from a web
page, a DB connection must be established. The easiest way to connect to a DB is to use a
DSN-_____ connection. A DSN-less connection can be used against
any _______________ DB on your web site.
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Create a DSN for an ODBC DB
Note that this configuration has to be done on the computer where your web site is located.
1. Open the ODBC icon in your Control Panel.
2. Choose the System DSN tab. 3. Click on Add in the System DSN tab.
4. Select the Microsoft Access Driver. Click Finish.
5. In the next screen, click Select to locate the database.
6. Give the database a Data Source Name (DSN).
7. Click OK. If your web site is located on a remote server,
you must have _________ access to that server, or ask your web host to do this for you.
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Create/Open a DB Connection For an Access DB called “hr.mdb" in a folder called
“fpdb” with your ASP file in the _____ directory, this code creates and opens a DSN-less ADO connection.<%
set conn=Server.CreateObject("ADODB.Connection")
conn.Provider="Microsoft.Jet.OLEDB.4.0"
conn.Open(Server.Mappath(“fpdb/hr.mdb"))
…%> If you have an ODBC DB with a _____ called “hr,"
connect to the DB with the following ASP code:<%
set conn=Server.CreateObject("ADODB.Connection")
conn.Open “hr"
…%>
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Create/Open a Recordset To be able to read database data, the data
must first be loaded into a _________. If you opened the DB connection with the first
set of code in the previous slide, you can access the “employee" table by adding the following code:set rs=Server.CreateObject("ADODB.recordset")
rs.Open "employee", conn
Or you could use _____ as follows:set rs=Server.CreateObject("ADODB.recordset")
rs.Open "Select * from employee", conn
This stores all table records in the recordset.
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Display Data To extract data from a recordset and then
close the recordset and connection, add the following code:
do until rs.EOF
for each x in rs.Fields ‘ “x” refers to a field
Response.Write(x.name) ‘ field name
Response.Write(" = ")
Response.Write(x.value & "<br />") ‘ field value
next
Response.Write("<br />")
rs.MoveNext ‘ move to next record in table
loop
rs.close
conn.close
Display Data in an HTML Table
File named display_employees.asp<html><body><% set conn=Server.CreateObject("ADODB.Connection")conn.Provider="Microsoft.Jet.OLEDB.4.0"conn.Open(Server.Mappath("fpdb/hr.mdb"))set rs=Server.CreateObject("ADODB.recordset")sql="SELECT * FROM employee"rs.Open sql, conn %><table border="1" width="100%"><tr> <% for each x in rs.Fields response.write("<th>" & x.name & "</th>") next %></tr>
<% do until rs.EOF %><tr> <% for each x in rs.Fields %> <td> <%
Response.Write(x.value) %> </td> <% next rs.MoveNext %></tr> <% loop rs.close conn.close %></table></body></html>
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Add Records I First create a form for
data input (form.htm):<html><body><form method="post"
action="add.asp">
<table><tr><td>SSN:</td><td><input name="ssn"></td></tr>
<tr><td>Last Name:</td><td><input name="lastname"></td></tr><tr><td>First Name:</td><td><input name="firstname"></td></tr> </table><br /><br /><input type="submit" value="Add
New"> <input type="reset" value="Cancel"></form></body></html>
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Add Records II Then create the ASP file to add records
(add.asp):<html><body><%set conn=Server.CreateObject("ADODB.Connection")conn.Provider="Microsoft.Jet.OLEDB.4.0"conn.Open(Server.Mappath(“fpdb/hr.mdb"))sql="INSERT INTO employee (ssn,lastname,firstname) VALUES "sql=sql & "('" & Request.Form("ssn") & "',"sql=sql & "'" & Request.Form(“lastname") & "',"sql=sql & "'" & Request.Form(“firstname") & "')"on error resume nextconn.Execute sql,recaffectedif err<>0 then Response.Write("No update permissions!")else Response.Write("<h3>" & recaffected & " record added</h3>")end ifconn.close%></body></html>
Update Records I: hr_listforupdate.asp This file displays all records in a special
way (continues on next slide):<html><body><%set conn=Server.CreateObject("ADODB.Connection")conn.Provider="Microsoft.Jet.OLEDB.4.0"conn.Open(Server.Mappath("../db/hr.mdb"))set rs=Server.CreateObject("ADODB.Recordset")rs.open "SELECT * FROM employee",conn%><h2>List Database</h2><table border="1" width="100%"><tr><%for each x in rs.Fields response.write("<th>" & ucase(x.name) & "</th>")next%></tr>
hr_listforupdate.asp (continued)<% do until rs.EOF %><tr><form method="post" action="hr_update.asp"><%for each x in rs.Fields if x.name="ssn" then%> <td> <input type="submit" name="ssn" value="<%=x.value%>"> </td> <%else%> <td> <%Response.Write(x.value)%> </td> <%end ifnext%></form><%rs.MoveNext%></tr><%loopconn.close%></table></body></html>
Update Records II: hr_update.asp<html><body><h2>Update Record</h2><%set conn=Server.CreateObject("ADODB.Connection")conn.Provider="Microsoft.Jet.OLEDB.4.0"conn.Open(Server.Mappath("fpdb/hr.mdb"))social=Request.Form("ssn")if Request.form("lastname")="" OR Request.form("firstname")="" then set rs=Server.CreateObject("ADODB.Recordset") rs.open "SELECT * FROM employee WHERE ssn ='" & social & "'", conn%> <form method="post" action="hr_update.asp"> <table> <%for each x in rs.Fields%> <tr> <td><%=x.name%></td> <td><input name="<%=x.name%>" value="<%=x.value%>" size="20"></td> <%next%> </tr> </table> <br /><br /> <input type="submit" value="Update record"> </form>
hr_update.asp (continued)<%
else
sql="UPDATE employee SET "
sql=sql & "lastname='" & Request.Form("lastname") & "',"
sql=sql & "firstname='" & Request.Form("firstname") & "'"
sql=sql & " WHERE ssn='" & social & "'"
on error resume next
conn.Execute sql
if err<>0 then
response.write("No update permissions!")
else
response.write("Record " & social & " was updated!")
end if
end if
conn.close
%>
</body>
</html>
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Delete Records I: hr_listfordelete.asp
This file is identical to hr_listforupdate.asp except for the following code:
<form method="post“ action="hr_delete.asp">
instead of:<form method="post“
action="hr_update.asp">
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Delete Records II: hr_delete.asp
This file is identical to hr_update.asp except for the following code:
sql="DELETE FROM employee"
sql=sql & " WHERE ssn='" & social & "'"
instead of:sql="UPDATE employee SET "
sql=sql & "lastname='" & _ Request.Form("lastname") & "',"
sql=sql & "firstname='" & _ Request.Form("firstname") & "'"
sql=sql & " WHERE ssn='" & _ social & "'"
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ADO Demonstration How to change the ________ rights of
your Access database: Open Windows Explorer, find the .mdb file. Right-click on the .mdb file and select ___________. Go to the _________ tab and set the access-rights
here. List, edit, update, and delete database record
s
Add a new record
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Using Access & FrontPage SMSU Computer Services has a web page
describing how to create a database connection using MS Access and FrontPage software.
SMSU Computer Services also has a tutorial on how to set up a form on a web page and connect it to an Access database.
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