/*
* 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.engine.SessionLocal;
import org.h2.expression.function.table.TableFunction;
import org.h2.result.ResultInterface;
import org.h2.schema.Schema;
/**
* A table backed by a system or user-defined function that returns a result
* set.
*/
public class FunctionTable extends VirtualConstructedTable {
private final TableFunction function;
public FunctionTable(Schema schema, SessionLocal session, TableFunction function) {
super(schema, 0, function.getName());
this.function = function;
function.optimize(session);
ResultInterface result = function.getValueTemplate(session);
int columnCount = result.getVisibleColumnCount();
Column[] cols = new Column[columnCount];
for (int i = 0; i < columnCount; i++) {
cols[i] = new Column(result.getColumnName(i), result.getColumnType(i));
}
setColumns(cols);
}
@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) {
return function.getValue(session);
}
@Override
public String getSQL(int sqlFlags) {
return function.getSQL(sqlFlags);
}
@Override
public StringBuilder getSQL(StringBuilder builder, int sqlFlags) {
return builder.append(function.getSQL(sqlFlags));
}
@Override
public boolean isDeterministic() {
return function.isDeterministic();
}
}