JDBC Drivers, JSP Tags, and ResultSet Implementation

JDBC Driver Types

Type 1: JDBC-ODBC Bridge

• Converts JDBC calls to ODBC
• ❌ Slow, platform dependent, and obsolete

Type 2: Native API Driver

• Uses database-specific native libraries
• ⚠️ Faster than Type 1 but platform dependent

Type 3: Network Protocol Driver

• Uses middleware server to connect
• 🌐 Platform independent but slower due to network

Type 4: Thin Driver

• Directly connects to database using pure Java
• ✅ Fast, platform independent, and most used

Tags in JSP

1. Directive Tags

• Provide instructions to the JSP container
• Syntax: <%@ ... %>
• Example: page, include, taglib

2. Scripting Tags

• Scriptlet Tag: Write Java code <% ... %>
• Expression Tag: Display output <%= ... %>
• Declaration Tag: Declare variables or methods <%! ... %>

3. Action Tags

• Perform actions like include or forward
• Syntax: <jsp:... />
• Example: <jsp:include>, <jsp:forward>

ResultSet and Its Types

In Java Database Connectivity (JDBC), a ResultSet is an object used to store the data returned from a database query (usually a SELECT statement).

1. TYPE_FORWARD_ONLY

• Cursor moves only forward
• Cannot go backward
• Default type

2. TYPE_SCROLL_INSENSITIVE

• Cursor can move forward and backward
• Does not reflect changes made in the database

3. TYPE_SCROLL_SENSITIVE

• Cursor moves in both directions
• Reflects database changes dynamically

Example of Creating ResultSet Types

Statement st = con.createStatement(
    ResultSet.TYPE_SCROLL_INSENSITIVE,
    ResultSet.CONCUR_READ_ONLY
);

RowSet and Its Types

In Java Database Connectivity (JDBC), a RowSet is an advanced version of ResultSet.

1. JdbcRowSet

• Connected RowSet
• Works like ResultSet
• Maintains a continuous database connection

2. CachedRowSet

• Disconnected RowSet
• Stores data in memory
• Can work without a database connection

3. WebRowSet

• Extension of CachedRowSet
• Can read/write data in XML format

4. FilteredRowSet

• Filters data based on conditions
• Shows only selected rows

5. JoinRowSet

• Combines data from multiple tables
• Works like an SQL JOIN