/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.ignite.internal.processors.query.h2.sql;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import org.apache.ignite.internal.util.typedef.F;
import org.h2.command.Parser;
import org.h2.util.StatementBuilder;
import org.h2.value.ValueString;
import static org.apache.ignite.internal.processors.query.h2.sql.GridSqlFunctionType.CASE;
import static org.apache.ignite.internal.processors.query.h2.sql.GridSqlFunctionType.CAST;
import static org.apache.ignite.internal.processors.query.h2.sql.GridSqlFunctionType.UNKNOWN_FUNCTION;
/**
* Function.
*/
public class GridSqlFunction extends GridSqlElement {
/** */
private static final Map<String, GridSqlFunctionType> TYPE_MAP = new HashMap<>();
/**
*
*/
static {
for (GridSqlFunctionType type : GridSqlFunctionType.values())
TYPE_MAP.put(type.name(), type);
}
/** */
private final String schema;
/** */
private final String name;
/** */
protected final GridSqlFunctionType type;
/**
* @param type Function type.
*/
public GridSqlFunction(GridSqlFunctionType type) {
this(null, type, type.functionName());
}
/**
* @param schema Schema.
* @param type Type.
* @param name Name.
*/
private GridSqlFunction(String schema, GridSqlFunctionType type, String name) {
super(new ArrayList<GridSqlAst>());
if (name == null)
throw new NullPointerException("name");
if (type == null)
type = UNKNOWN_FUNCTION;
this.schema = schema;
this.name = name;
this.type = type;
}
/**
* @param schema Schema.
* @param name Name.
*/
public GridSqlFunction(String schema, String name) {
this(schema, TYPE_MAP.get(name), name);
}
/** {@inheritDoc} */
@Override public String getSQL() {
StatementBuilder buff = new StatementBuilder();
if (schema != null)
buff.append(Parser.quoteIdentifier(schema)).append('.');
// We don't need to quote identifier as long as H2 never does so with function names when generating plan SQL.
// On the other hand, quoting identifiers that also serve as keywords (like CURRENT_DATE() and CURRENT_DATE)
// turns CURRENT_DATE() into "CURRENT_DATE"(), which is not good.
buff.append(name);
if (type == CASE) {
buff.append(' ').append(child().getSQL());
for (int i = 1, len = size() - 1; i < len; i += 2) {
buff.append(" WHEN ").append(child(i).getSQL());
buff.append(" THEN ").append(child(i + 1).getSQL());
}
if ((size() & 1) == 0)
buff.append(" ELSE ").append(child(size() - 1).getSQL());
return buff.append(" END").toString();
}
buff.append('(');
switch (type) {
case CAST:
case CONVERT:
assert size() == 1;
String castType = resultType().sql();
assert !F.isEmpty(castType) : castType;
buff.append(child().getSQL());
buff.append(type == CAST ? " AS " : ",");
buff.append(castType);
break;
case EXTRACT:
ValueString v = (ValueString)((GridSqlConst)child(0)).value();
buff.append(v.getString()).append(" FROM ").append(child(1).getSQL());
break;
case TABLE:
for (int i = 0; i < size(); i++) {
buff.appendExceptFirst(", ");
GridSqlElement e = child(i);
// id int = ?, name varchar = ('aaa', 'bbb')
buff.append(Parser.quoteIdentifier(((GridSqlAlias)e).alias()))
.append(' ')
.append(e.resultType().sql())
.append('=')
.append(e.child().getSQL());
}
break;
default:
for (int i = 0; i < size(); i++) {
buff.appendExceptFirst(", ");
buff.append(child(i).getSQL());
}
}
return buff.append(')').toString();
}
/**
* @return Name.
*/
public String name() {
return name;
}
/**
* @return Type.
*/
public GridSqlFunctionType type() {
return type;
}
}