Difference between revisions of "C#:Read From a Database"

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(Read from a SQL Server database)
(Read from a MySQL database)
Line 63: Line 63:
 
*OdbcConnection
 
*OdbcConnection
 
*OdbcDataReader
 
*OdbcDataReader
The Odbc connection, (this one is called MySQLscott) must be created first.
+
The Odbc connection must be created first; this one is called MySQLscott.
 
*Download the mysql-odbc-connector from mysql.com
 
*Download the mysql-odbc-connector from mysql.com
*Create the ODBC connection from Start/Control Panel/Administrative Tools/Datasources (ODBC)
+
*Create the ODBC connection from Start/Control Panel/Administrative Tools/Datasources (ODBC)/System DSN
 
<p class="imper">Read the name and population for each country
 
<p class="imper">Read the name and population for each country
 
with a population of more than 200000000.
 
with a population of more than 200000000.

Revision as of 07:57, 19 June 2008

The .Net framework includes several "parallel" namespaces that connect you to a database. System.Data.SqlClient connects to Microsoft's own database SQL Server; alternatives include System.Data.Odbc and System.Data.OleDb and System.Data.OracleClient

Read from a SQL Server database

To read from a SQL Server database you can use the classes in System.Data.SqlClient

  • SqlCommand
  • SqlConnection
  • SqlDataReader
Connection parameters
valuedescription
127.0.0.1 the IP address database server;
gisq the name of the database;
scott user name;
tiger the password;

Read the name and population for each country with a population of more than 200000000.

The SQL statement is:
SELECT name, population
FROM bbc
WHERE population>200000000

The table bbc has columns:

  • name
  • region
  • area
  • population
  • gdp


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Read from a MySQL database

To read from a non SQL Server database you can use the classes in System.Data.OdbcClient

  • OdbcCommand
  • OdbcConnection
  • OdbcDataReader

The Odbc connection must be created first; this one is called MySQLscott.

  • Download the mysql-odbc-connector from mysql.com
  • Create the ODBC connection from Start/Control Panel/Administrative Tools/Datasources (ODBC)/System DSN

Read the name and population for each country with a population of more than 200000000.


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