/**
* Construct a local result set by reading all data from a regular result set.
*
* @param session the session
* @param rs the result set
* @param maxrows the maximum number of rows to read (0 for no limit)
* @return the local result set
*/
public static LocalResult read(Session session, ResultSet rs, int maxrows) {
Expression[] cols = Expression.getExpressionColumns(session, rs);
int columnCount = cols.length;
LocalResult result = new LocalResult(session, cols, columnCount);
try {
for (int i = 0; (maxrows == 0 || i < maxrows) && rs.next(); i++) {
Value[] list = new Value[columnCount];
for (int j = 0; j < columnCount; j++) {
int type = result.getColumnType(j);
list[j] = DataType.readValue(rs, j + 1, type);
}
result.addRow(list);
}
} catch (SQLException e) {
throw DbException.convert(e);
}
result.done();
return result;
}
/**
* Create a shallow copy of the result set. The data and a temporary table (if there is any) is
* not copied.
*
* @param targetSession the session of the copy
* @return the copy if possible, or null if copying is not possible
*/
public LocalResult createShallowCopy(Session targetSession) {
if (rows == null || rows.size() < rowCount) {
return null;
}
LocalResult copy = new LocalResult();
copy.maxMemoryRows = this.maxMemoryRows;
copy.session = targetSession;
copy.visibleColumnCount = this.visibleColumnCount;
copy.expressions = this.expressions;
copy.rowId = -1;
copy.rowCount = this.rowCount;
copy.rows = this.rows;
copy.sort = this.sort;
copy.distinctRows = this.distinctRows;
copy.distinct = distinct;
copy.randomAccess = randomAccess;
copy.currentRow = null;
copy.offset = 0;
copy.limit = -1;
return copy;
}
