How to Efficiently Iterate Through a Java ResultSet and Retrieve Multiple Rows?

Iterating Through a Result Set in Java

When working with a ResultSet object in Java, it is essential to iterate through its rows to retrieve the desired data. This question demonstrates how to extract one row of data, but more commonly multiple rows need to be extracted.

Solution to the problem

The following code demonstrates how to loop through the result set and use two different lists (sids and lids) to store the corresponding column values:

List<String> sids = new ArrayList<String>();
List<String> lids = new ArrayList<String>();

String query = "SELECT rlink_id, COUNT(*)"
             + "FROM dbo.Locate  "
             + "GROUP BY rlink_id ";

Statement stmt = yourconnection.createStatement();
try {
    ResultSet rs4 = stmt.executeQuery(query);

    while (rs4.next()) {
        sids.add(rs4.getString(1));
        lids.add(rs4.getString(2));
    }
} finally {
    stmt.close();
}

String[] show = sids.toArray(sids.size());
String[] actuate = lids.toArray(lids.size());

Code Description

• The two lists sids and lids are initialized to store the corresponding columns the extracted value.
• Creates a ResultSet object using the given query.
• The while loop iterates through the result set, getting the values ​​of the two columns of each row and adding them to the list.
• Finally, convert the list to an array to access the extracted data when needed.

Using this approach, you can efficiently iterate over the result set and use the extracted data as needed.

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