/*
* 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.expression;
import org.h2.api.ErrorCode;
import org.h2.engine.SessionLocal;
import org.h2.expression.condition.Comparison;
import org.h2.message.DbException;
import org.h2.table.Column;
import org.h2.value.TypeInfo;
import org.h2.value.Value;
import org.h2.value.ValueNull;
import org.h2.value.ValueVarchar;
/**
* A parameter of a prepared statement.
*/
public final class Parameter extends Operation0 implements ParameterInterface {
private Value value;
private Column column;
private final int index;
public Parameter(int index) {
this.index = index;
}
@Override
public StringBuilder getUnenclosedSQL(StringBuilder builder, int sqlFlags) {
return builder.append('?').append(index + 1);
}
@Override
public void setValue(Value v, boolean closeOld) {
// don't need to close the old value as temporary files are anyway
// removed
this.value = v;
}
public void setValue(Value v) {
this.value = v;
}
@Override
public Value getParamValue() {
if (value == null) {
// to allow parameters in function tables
return ValueNull.INSTANCE;
}
return value;
}
@Override
public Value getValue(SessionLocal session) {
return getParamValue();
}
@Override
public TypeInfo getType() {
if (value != null) {
return value.getType();
}
if (column != null) {
return column.getType();
}
return TypeInfo.TYPE_UNKNOWN;
}
@Override
public void checkSet() {
if (value == null) {
throw DbException.get(ErrorCode.PARAMETER_NOT_SET_1, "#" + (index + 1));
}
}
@Override
public Expression optimize(SessionLocal session) {
if (session.getDatabase().getMode().treatEmptyStringsAsNull) {
if (value instanceof ValueVarchar && value.getString().isEmpty()) {
value = ValueNull.INSTANCE;
}
}
return this;
}
@Override
public boolean isValueSet() {
return value != null;
}
@Override
public boolean isEverything(ExpressionVisitor visitor) {
switch (visitor.getType()) {
case ExpressionVisitor.INDEPENDENT:
return value != null;
default:
return true;
}
}
@Override
public int getCost() {
return 0;
}
@Override
public Expression getNotIfPossible(SessionLocal session) {
return new Comparison(Comparison.EQUAL, this, ValueExpression.FALSE, false);
}
public void setColumn(Column column) {
this.column = column;
}
public int getIndex() {
return index;
}
}