What is Result set in java?

Answer 1

A table of data representing a database result set, which is usually generated by executing a statement that queries the database.

A ResultSet object maintains a cursor pointing to its current row of data. Initially the cursor is positioned before the first row. The next method moves the cursor to the next row, and because it returns false when there are no more rows in the ResultSet object, it can be used in a while loop to iterate through the result set.

A default ResultSet object is not updatable and has a cursor that moves forward only. Thus, you can iterate through it only once and only from the first row to the last row. It is possible to produce ResultSet objects that are scrollable and/or updatable. The following code fragment, in which con is a valid Connection object, illustrates how to make a result set that is scrollable and insensitive to updates by others, and that is updatable. See ResultSet fields for other options. Statement stmt = con.createStatement( ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE); ResultSet rs = stmt.executeQuery("SELECT a, b FROM TABLE2"); // rs will be scrollable, will not show changes made by others, // and will be updatable In simple words, result set can store the result of the database query(SQL query).

Visit here for more: docs.oracle.com/javase/1.4.2/docs/api/java/sql/ResultSet.html

Answer 2

java.sql.ResultSet is a java object that is used for database connectivity to hold the data returned by a select query.

When we run a select query it returns us the data in a table format with each row representing one logical group of data with a number of columns.

The result set would contain this table of data and each row can be accessed one by one. we can use the resultset.get() methods to get the data from it.

Example:

ResultSet rs = prepStmt.executeQuery(); //Assumption - prepStmt is a valid preparedstatement with a valid query

while(rs.next()){

System.out.println("Name: " + rs.getString(1));

System.out.println("Age: " + rs.getInt(2));

}

the rs.getString() method would return us a String data type and similarly the rs.getInt() would return us an integer data type

the numbers 1 & 2 represent the column position in the result set where our data is present.

Answer 3

To get the results of a database query, which you can then process. Please note that an SQL SELECT command will often produce a result that consists of many rows (records) of data.