/*
* Copyright 2004-2023 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.table;
import org.h2.command.dml.DataChangeStatement;
import org.h2.engine.SessionLocal;
import org.h2.expression.Expression;
import org.h2.expression.ExpressionColumn;
import org.h2.result.LocalResult;
import org.h2.result.ResultInterface;
import org.h2.result.ResultTarget;
import org.h2.result.Row;
import org.h2.schema.Schema;
/**
* A data change delta table.
*/
public class DataChangeDeltaTable extends VirtualConstructedTable {
/**
* Result option.
*/
public enum ResultOption {
/**
* OLD row.
*/
OLD,
/**
* NEW row with evaluated default expressions, but before triggers.
*/
NEW,
/**
* FINAL rows after triggers.
*/
FINAL;
}
/**
* Collects final row for INSERT operations.
*
* @param session
* the session
* @param table
* the table
* @param deltaChangeCollector
* target result
* @param deltaChangeCollectionMode
* collection mode
* @param newRow
* the inserted row
*/
public static void collectInsertedFinalRow(SessionLocal session, Table table, ResultTarget deltaChangeCollector,
ResultOption deltaChangeCollectionMode, Row newRow) {
if (session.getMode().takeInsertedIdentity) {
Column column = table.getIdentityColumn();
if (column != null) {
session.setLastIdentity(newRow.getValue(column.getColumnId()));
}
}
if (deltaChangeCollectionMode == ResultOption.FINAL) {
deltaChangeCollector.addRow(newRow.getValueList());
}
}
private final DataChangeStatement statement;
private final ResultOption resultOption;
private final Expression[] expressions;
public DataChangeDeltaTable(Schema schema, SessionLocal session, DataChangeStatement statement,
ResultOption resultOption) {
super(schema, 0, statement.getStatementName());
this.statement = statement;
this.resultOption = resultOption;
Table table = statement.getTable();
Column[] tableColumns = table.getColumns();
int columnCount = tableColumns.length;
Column[] c = new Column[columnCount];
for (int i = 0; i < columnCount; i++) {
c[i] = tableColumns[i].getClone();
}
setColumns(c);
Expression[] expressions = new Expression[columnCount];
String tableName = getName();
for (int i = 0; i < columnCount; i++) {
expressions[i] = new ExpressionColumn(database, null, tableName, c[i].getName());
}
this.expressions = expressions;
}
@Override
public boolean canGetRowCount(SessionLocal session) {
return false;
}
@Override
public long getRowCount(SessionLocal session) {
return Long.MAX_VALUE;
}
@Override
public long getRowCountApproximation(SessionLocal session) {
return Long.MAX_VALUE;
}
@Override
public ResultInterface getResult(SessionLocal session) {
statement.prepare();
int columnCount = expressions.length;
LocalResult result = new LocalResult(session, expressions, columnCount, columnCount);
result.setForDataChangeDeltaTable();
statement.update(result, resultOption);
return result;
}
@Override
public StringBuilder getSQL(StringBuilder builder, int sqlFlags) {
return builder.append(resultOption.name()).append(" TABLE (").append(statement.getSQL()).append(')');
}
@Override
public boolean isDeterministic() {
return false;
}
}