Getting started with JDBC

The result set is the output of the database query data from the SQL statement. The SELECT statements read data from database query return data in to result set.

Object Result set is used to maintain cursor point of current row in result set. The result set is the combination of column and row data in object. The Result set interface has three categories in method:

• Navigational methods: It is cursor to move around.
• Method Get: display the data in columns of current row pointed by cursor.
• Method Update: used to update data in columns of current row

JDBC allow following connection methods:

• createStatement(int RS_Type, int RS_Concurrency);
• prepareStatement(String sql_query, int RS_Type, int RS_Concurrency);
• prepareCall(String sql_query, int RS_Type, int RS_Concurrency);

Type of Result Set: The type of resultset is shown below:

Concurrency of Result Set: The types of concurrency are:

try {
   Statement stmtmnt = conn1.createStatement(
       ResultSet.CONCUR_READ_ONLY,
       ResultSet.TYPE_FORWARD_ONLY
    );
}
catch(Exception ex) { 
}
finally { 
}

Navigate Result Set: Some of the methods on for moving the cursor are:

• public void beforeFirst() throws SQLException{}

         Cursor is moved just before the First row

• public boolean first() throws SQLException{}

   Cursor is moved to first row

• public void afterLast() throws SQLException{}

    Cursor is moved after last row

• public void last() throws SQLException{}

    Cursor is moved to last row

• public boolean absolute(int row) throws SQLException{}

        Cursor is moved to specified row

• public boolean previous() throws SQLException{}

        Cursor is moved to previous row.

• public boolean next() throws SQLException{}

        Cursor is moved to next row.

• public int getRow() throws SQLException{}

        Cursor pointing row number is returned.

Viewing a Result Set:

Getting the data from the resultset has two methods:

• public int getInt(String columnName) throws SQLException{}

        Return current row position based on column name

• public int getInt(int columnIndex) throws SQLException{}

        Return currentrow based on the column index

Updating a Result Set:

This will update data in result set. One takes column name and other takes the column index.

• public void updateString(int columnIndexID, String s) throws SQLException{}

      Changes the string specified by the columnIndexID to s

• public void updateString(String columnName, String s) throws SQLException{}

   Changes the string specified by the columnName to s

Update the resultset will not make any change in the database, it make changes to the resultset. If we have to make change to the database we need use below methods:

• public void insertRow()

  It will insert new row into database

• public void cancelRowUpdates()

  It will cancel the row update in database

• public void deleteRow()

 It will delete row from the database

• public void updateRow()

It will update row into the database.