Database Connection Using ADODB

1. ADODB. Connection  (connection in java script)

we can use this class to establish onneton to database

to us the methods of this class create an object like below

syn: set objname= createobject ("connection")

 eg : set reynolds = createobject("pen")

(object) (class)

Example :

Dim cn

set cn= createobject ("ADODB.connection")

Ms-Access : cn.open" provider= microsoft.jet.dedb.4.0: database=path

of db" Ms-Access

(cn.open"DSN=datasourcename")

Sql server: cn.open' provider = SQLOLEDB; datasource= serveaddress;

vid= "--";pwd="--"; database=dbname"

 SQL server

oracle : cn.open provider=MSDAORA; database=address=; vid="--";pwd="--";"      

'providers can be of different kinds , ask your

developer to know the exact provider which thery using

cn.open  : will establish connection to database

'**********************************************************************************************

2.  ADODb.command

we can use this class to perform  the DML transaction insert, update & delete

'syn: set command name = createobject("ADOBE.command")

Example :

dim cn,cmd

set cn= createobject("ADODB.connection"

set cmd= createobject("ADODB.command")

cn.open "DSN=r1"

cmd.activeconnection=cn

cmd.commandtext="insert into emp values('002', 'james', 20000)"

cmd. execute

'**********************************************************************************************

'3.  ADODB.recordset

we can use this class to select the data form existing data files. any data

selected from the db is stored in record set object

syn: set record set name = create object ("ADODB.recordset")

Example :

   dim cn,rs

   set cn= createobject ("ADODB.connection")

   set rs= createobject ("ADODB.recordset")

   cn.open "DSN=r1"

   rs.open "select*from emp",cn

   rs.move first

   while rs.eof<>true

   msgbox rs ("eno") & "  " & ("ename")& "  " &("sal")

   rs.movenext

   wend

   cn.close

**************************************************************************************************
record set object has the below methods

1) rs.open  : this method is used to execute the SQL statement and select records

 form database

syntax :  rs.open "sql statement", connection object

 rs.movefirst - goto first record

 rs.movenext  _ goto next record

rs.moveprev  _ goto previous record

 rs.movelast  _ goto last record

rs.rowcount  _ count no.of records

 rs ("fieldname") _ select the value in the field

 rs.close     _ close recordset object