How can I get data from multiple ResultSets?

John Zukowski

With certain database systems, a stored procedure can return multiple result sets, multiple update counts, or some combination of both. Also, if you are providing a user with the ability to enter any SQL statement, you don't know if you are going to get a ResultSet or an update count back from each statement, without analyzing the contents. The Statement.execute() method helps in these cases.

Method Statement.execute() returns a boolean to tell you the type of response:

  • true indicates next result is a ResultSet
    Use Statement.getResultSet to get the ResultSet
  • false indicates next result is an update count
    Use Statement.getUpdateCount to get the update count
  • false also indicates no more results
    Update count is -1 when no more results (usually 0 or positive)

After processing each response, you use Statement.getMoreResults to check for more results, again returning a boolean. The following demonstrates the processing of multiple result sets:

boolean result = stmt.execute(" ... ");
int updateCount = stmt.getUpdateCount();

while (result || (updateCount != -1)) {
  if(result) {
    ResultSet r = stmt.getResultSet();
    // process result set
  } else if(updateCount != -1) {
    // process update count
  result = stmt.getMoreResults(); 
  updateCount = stmt.getUpdateCount();