/*
* 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.db2.parser;
import com.alibaba.druid.sql.ast.SQLExpr;
import com.alibaba.druid.sql.ast.SQLSetQuantifier;
import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
import com.alibaba.druid.sql.dialect.db2.ast.stmt.DB2SelectQueryBlock;
import com.alibaba.druid.sql.dialect.db2.ast.stmt.DB2SelectQueryBlock.Isolation;
import com.alibaba.druid.sql.parser.ParserException;
import com.alibaba.druid.sql.parser.SQLExprParser;
import com.alibaba.druid.sql.parser.SQLSelectParser;
import com.alibaba.druid.sql.parser.Token;
public class DB2SelectParser extends SQLSelectParser {
public DB2SelectParser(SQLExprParser exprParser){
super(exprParser);
}
public DB2SelectParser(String sql){
this(new DB2ExprParser(sql));
}
protected SQLExprParser createExprParser() {
return new DB2ExprParser(lexer);
}
@Override
public SQLSelectQuery query() {
if (lexer.token() == Token.LPAREN) {
lexer.nextToken();
SQLSelectQuery select = query();
accept(Token.RPAREN);
return queryRest(select);
}
accept(Token.SELECT);
if (lexer.token() == Token.COMMENT) {
lexer.nextToken();
}
DB2SelectQueryBlock queryBlock = new DB2SelectQueryBlock();
if (lexer.token() == Token.DISTINCT) {
queryBlock.setDistionOption(SQLSetQuantifier.DISTINCT);
lexer.nextToken();
} else if (lexer.token() == Token.UNIQUE) {
queryBlock.setDistionOption(SQLSetQuantifier.UNIQUE);
lexer.nextToken();
} else if (lexer.token() == Token.ALL) {
queryBlock.setDistionOption(SQLSetQuantifier.ALL);
lexer.nextToken();
}
parseSelectList(queryBlock);
parseFrom(queryBlock);
parseWhere(queryBlock);
parseGroupBy(queryBlock);
for (;;) {
if (lexer.token() == Token.FETCH) {
lexer.nextToken();
accept(Token.FIRST);
SQLExpr first = this.exprParser.primary();
queryBlock.setFirst(first);
if (identifierEquals("ROW") || identifierEquals("ROWS")) {
lexer.nextToken();
}
accept(Token.ONLY);
continue;
}
if (lexer.token() == Token.WITH) {
lexer.nextToken();
if (identifierEquals("RR")) {
queryBlock.setIsolation(Isolation.RR);
} else if (identifierEquals("RS")) {
queryBlock.setIsolation(Isolation.RS);
} else if (identifierEquals("CS")) {
queryBlock.setIsolation(Isolation.CS);
} else if (identifierEquals("UR")) {
queryBlock.setIsolation(Isolation.UR);
} else {
throw new ParserException("TODO");
}
lexer.nextToken();
continue;
}
if (lexer.token() == Token.FOR) {
lexer.nextToken();
acceptIdentifier("READ");
accept(Token.ONLY);
queryBlock.setForReadOnly(true);
}
if (lexer.token() == Token.OPTIMIZE) {
lexer.nextToken();
accept(Token.FOR);
queryBlock.setOptimizeFor(this.expr());
if (identifierEquals("ROW")) {
lexer.nextToken();
} else {
acceptIdentifier("ROWS");
}
}
break;
}
return queryRest(queryBlock);
}
}