Assigning a specific entry in the ResultSet to a variable
I want to get a set of records from a database, do rs.next (), and then assign the result of that to a variable to navigate to the method that will use that record, in the same way I am not assigning it to a variable and passing it to the method. or a way to do it? I am using JAVA (1.5)
Thanks for all the answers
I don't want to pass the entire resultSet to the method, only the current row, but as I understand it, this cannot be done
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Do you want to assign the result to rs.next () variable?
I'm afraid you can't do this. You can have a link from that rs and handle it in a different way (just like you wouldn't assign it to var)
When you pass rs as an argument to a method, which is exactly what you are already doing.
while( rs.next() ) {
list.add( createFrom( rs ) );
}
...
public Object createFrom( ResultSet rs ) { // Here rs is a copy of the reference in the while above.
}
Did I understand your question correctly?
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No, this is not supported out of the box, but maybe the following idea can help you:
ResultSetMetaData meta = rs.getMetaData();
while (rs.next()) {
Map<String,Object> row = new HashMap<String,Object>();
for (int i = 1; i <= meta.getColumnCount(); ++i) {
row.put(meta.getColumnName(i), rs.getObject(i));
}
processRow(row);
}
The problem is that you need to map the values from row
-map to processRow()
, and that won't work for all type / driver combinations (BLOB, ...).
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I think I understand you now. :)
No, it cannot be done like this. ResultSet
changes its internal state on every call to ResultSet.next()
, so keeping a reference to it won't get you. You need to extract the data you want into some custom object and save it.
CustomData cd = new CustomData();
cd.setString1(rs.getString(1));
cd.setInt1(rs.getInt(2));
...
Then you can save the variable cd
and continue processing ResultSet
.
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