/*
* Copyright 1999-2011 Alibaba Group Holding Ltd.
*
* Licensed 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 com.alibaba.druid.sql.dialect.postgresql.parser;
import com.alibaba.druid.sql.ast.SQLExpr;
import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
import com.alibaba.druid.sql.ast.expr.SQLBinaryOperator;
import com.alibaba.druid.sql.dialect.postgresql.ast.PGOrderBy;
import com.alibaba.druid.sql.parser.Lexer;
import com.alibaba.druid.sql.parser.SQLExprParser;
import com.alibaba.druid.sql.parser.Token;
public class PGExprParser extends SQLExprParser {
public final static String[] AGGREGATE_FUNCTIONS = { "AVG", "COUNT", "MAX", "MIN", "STDDEV", "SUM", "ROW_NUMBER" };
public PGExprParser(String sql){
this(new PGLexer(sql));
this.lexer.nextToken();
}
public PGExprParser(Lexer lexer){
super(lexer);
this.aggregateFunctions = AGGREGATE_FUNCTIONS;
}
@Override
public PGOrderBy parseOrderBy() {
if (lexer.token() == (Token.ORDER)) {
PGOrderBy orderBy = new PGOrderBy();
lexer.nextToken();
if (identifierEquals("SIBLINGS")) {
lexer.nextToken();
orderBy.setSibings(true);
}
accept(Token.BY);
orderBy.addItem(parseSelectOrderByItem());
while (lexer.token() == (Token.COMMA)) {
lexer.nextToken();
orderBy.addItem(parseSelectOrderByItem());
}
return orderBy;
}
return null;
}
public SQLExpr primaryRest(SQLExpr expr) {
if (lexer.token() == Token.COLONCOLON) {
lexer.nextToken();
SQLExpr typeExpr = this.expr();
SQLBinaryOpExpr castExpr = new SQLBinaryOpExpr(expr, SQLBinaryOperator.PostgresStyleTypeCast, typeExpr);
return primaryRest(castExpr);
}
return super.primaryRest(expr);
}
}