To create new records, use INSERT statements.

INSERT Syntax

The INSERT statement specifies the columns to be inserted and the new column values. You can specify the column values in a comma-separated list in the VALUES clause, as shown in the following example:

INSERT INTO <table_name> 
( <column_reference> [ , ... ] )
VALUES 
( { <expression> | NULL } [ , ... ] ) 
  

<expression> ::=
  | @ <parameter> 
  | ?
  | <literal>

You can use the executeUpdate method of the Statement and PreparedStatement classes to execute data manipulation commands and retrieve the rows affected. To retrieve the Id of the last inserted record use getGeneratedKeys. Additionally, set the RETURN_GENERATED_KEYS flag of the Statement class when you call prepareStatement.

String cmd = "INSERT INTO Comments (Text) VALUES (?)";
PreparedStatement pstmt = connection.prepareStatement(cmd,Statement.RETURN_GENERATED_KEYS);
pstmt.setString(1, "New to do");
int count = pstmt.executeUpdate();
System.out.println(count+" rows were affected");
ResultSet rs = pstmt.getGeneratedKeys();
while(rs.next()){	  
  System.out.println(rs.getString("Id"));
}
connection.close();