Immediately after your execute statement you can have an if statement. For example
ResultSet rs = statement.execute();
if (!rs.next()){
//ResultSet is empty
}
Calculates the size of the java.sql.ResultSet:
int size = 0;
if (rs != null) {
rs.beforeFirst();
rs.last();
size = rs.getRow();
}
(Source)
Definitely this gives good solution,
ResultSet rs = stmt.execute("SQL QUERY");
// With the above statement you will not have a null ResultSet 'rs'.
// In case, if any exception occurs then next line of code won't execute.
// So, no problem if I won't check rs as null.
if (rs.next()) {
do {
// Logic to retrieve the data from the resultset.
// eg: rs.getString("abc");
} while(rs.next());
} else {
// No data
}
If you use rs.next() you will move the cursor, than you should to move first() why don't check using first() directly?
public void fetchData(ResultSet res, JTable table) throws SQLException{
ResultSetMetaData metaData = res.getMetaData();
int fieldsCount = metaData.getColumnCount();
for (int i = 1; i <= fieldsCount; i++)
((DefaultTableModel) table.getModel()).addColumn(metaData.getColumnLabel(i));
if (!res.first())
JOptionPane.showMessageDialog(rootPane, "no data!");
else
do {
Vector<Object> v = new Vector<Object>();
for (int i = 1; i <= fieldsCount; i++)
v.addElement(res.getObject(i));
((DefaultTableModel) table.getModel()).addRow(v);
} while (res.next());
res.close();
}
if (rs == null || !rs.first()) {
//empty
} else {
//not empty
}
Note that after this method call, if the resultset is not empty, it is at the beginning.
Do this using rs.next():
while (rs.next())
{
...
}
If the result set is empty, the code inside the loop won't execute.
Source: Stackoverflow.com