Connecting to a Database
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We create an object of the Connection interface to establish a connection of the Java application with a database. We can create multiple Connection objects in a Java application to access and retrieve data from multiple databases. The DriverManager class provides the getConnection ( ) method to create a Connection object. |
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The getConnection ( ) method is an overloaded method that has following three forms: |
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1. Connection getConnection(String ): Accept the JDBC URL of the database, which we need tom access , as a parameter. |
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String url= “jdbc:odbc:MyDSN”; |
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Connection con =DriverManager.getConnection(url); |
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The syntax for a JDBC URL that is passed as a parameter to the getConnection ( ) method is: |
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<protocol>:<subprotocal>:<subname> |
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A JDBC URL has the following three components: |
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Protocol name: It indicate the name of the protocol that is used to access a database. In JDBC the name of the access protocol is always jdbc. |
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Sub-protocol name: It indicate the mechanism to retrieve data from a database. For example if we use the JDBC-ODBC Bridge driver to access a database, then the name of sub-protocol is odbc. |
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Subname: It indicates the Data Source Name(DSN) that contain databases information, such as the name of a database, location of the database server, user name and password to access a database server. |
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2. Connection getConnection(String , String , String ): |
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Ex: String url= “jdbc:odbc:MyDSN”; |
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Driver d =new ; |
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Connection con =DriverManager.getConnection(url, “ NewUser”, “NewPassword”); |
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3. Connection getConnection(String , Properties): |
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Ex: |
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String url= “jdbc:odbc:MyDSN”; |
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Properties p new Properties( ); |
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p.setProperty(“user”,”NewUser”); |
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p.setProperty(“password”,”newPassword”); |
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Connection con =DriverManager.getConnection(url, p); |