How to Avoid a 'Before Start of Result Set' Exception When Handling ResultSet Data?

ResultSet Exception: "Before Start of Result Set"

Executing a query returns a ResultSet object containing retrieved data rows. However, the cursor initially points before the first row, resulting in the "Before start of result set" exception when trying to retrieve data.

Cause:

The error occurs when accessing ResultSet data without first positioning the cursor on a valid row.

Solution:

To resolve the issue, move the cursor to the first row before attempting to retrieve data using the following code:

result.next();
String foundType = result.getString(1);

Enhanced Code Snippet:

String sql = "SELECT type FROM node WHERE nid = ?";
PreparedStatement prep = conn.prepareStatement(sql);
int meetNID = Integer.parseInt(node.get(BoutField.field_meet_nid));
prep.setInt(1, meetNID);

ResultSet result = prep.executeQuery();
if (result.next()) { // Move cursor to first row
  String foundType = result.getString(1);
  ... // code to validate type
} else {
  throw new IllegalArgumentException(String.format("Node %d must be of type 'meet', but was %s", meetNID, foundType));
}

This modification ensures that the cursor is positioned on the first row of the ResultSet before accessing data, preventing the "Before start of result set" exception.

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