org.h2.index.LinkedCursor Maven / Gradle / Ivy
/*
* Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.index;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.h2.engine.Session;
import org.h2.message.DbException;
import org.h2.result.Row;
import org.h2.result.SearchRow;
import org.h2.table.Column;
import org.h2.table.TableLink;
import org.h2.value.DataType;
import org.h2.value.Value;
/**
* The cursor implementation for the linked index.
*/
public class LinkedCursor implements Cursor {
private final TableLink tableLink;
private final PreparedStatement prep;
private final String sql;
private final Session session;
private final ResultSet rs;
private Row current;
LinkedCursor(TableLink tableLink, ResultSet rs, Session session,
String sql, PreparedStatement prep) {
this.session = session;
this.tableLink = tableLink;
this.rs = rs;
this.sql = sql;
this.prep = prep;
}
@Override
public Row get() {
return current;
}
@Override
public SearchRow getSearchRow() {
return current;
}
@Override
public boolean next() {
try {
boolean result = rs.next();
if (!result) {
rs.close();
tableLink.reusePreparedStatement(prep, sql);
current = null;
return false;
}
} catch (SQLException e) {
throw DbException.convert(e);
}
current = tableLink.getTemplateRow();
for (int i = 0; i < current.getColumnCount(); i++) {
Column col = tableLink.getColumn(i);
Value v = DataType.readValue(session, rs, i + 1, col.getType().getValueType());
current.setValue(i, v);
}
return true;
}
@Override
public boolean previous() {
throw DbException.throwInternalError(toString());
}
}