/*
* 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.parser;
import com.alibaba.druid.sql.ast.SQLExpr;
import com.alibaba.druid.sql.ast.SQLOrderBy;
import com.alibaba.druid.sql.ast.SQLSetQuantifier;
import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
import com.alibaba.druid.sql.ast.statement.SQLJoinTableSource;
import com.alibaba.druid.sql.ast.statement.SQLSelect;
import com.alibaba.druid.sql.ast.statement.SQLSelectGroupByClause;
import com.alibaba.druid.sql.ast.statement.SQLSelectItem;
import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
import com.alibaba.druid.sql.ast.statement.SQLSubqueryTableSource;
import com.alibaba.druid.sql.ast.statement.SQLTableSource;
import com.alibaba.druid.sql.ast.statement.SQLUnionOperator;
import com.alibaba.druid.sql.ast.statement.SQLUnionQuery;
public class SQLSelectParser extends SQLParser {
public SQLSelectParser(String sql){
super(sql);
}
public SQLSelectParser(Lexer lexer){
super(lexer);
}
public SQLSelect select() throws ParserException {
SQLSelect select = new SQLSelect();
select.setQuery(query());
select.setOrderBy(parseOrderBy());
if (select.getOrderBy() == null) {
select.setOrderBy(parseOrderBy());
}
return select;
}
public SQLSelectQuery queryRest(SQLSelectQuery selectQuery) throws ParserException {
if (lexer.token() == Token.UNION) {
lexer.nextToken();
SQLUnionQuery union = new SQLUnionQuery();
union.setLeft(selectQuery);
if (lexer.token() == Token.ALL) {
union.setOperator(SQLUnionOperator.UNION_ALL);
lexer.nextToken();
}
SQLSelectQuery right = this.query();
union.setRight(right);
return union;
}
if (lexer.token() == Token.INTERSECT) {
lexer.nextToken();
SQLUnionQuery union = new SQLUnionQuery();
union.setLeft(selectQuery);
union.setOperator(SQLUnionOperator.INTERSECT);
SQLSelectQuery right = this.query();
union.setRight(right);
return union;
}
if (lexer.token() == Token.MINUS) {
lexer.nextToken();
SQLUnionQuery union = new SQLUnionQuery();
union.setLeft(selectQuery);
union.setOperator(SQLUnionOperator.MINUS);
SQLSelectQuery right = this.query();
union.setRight(right);
return union;
}
return selectQuery;
}
public SQLSelectQuery query() throws ParserException {
if (lexer.token() == Token.LPAREN) {
lexer.nextToken();
SQLSelectQuery select = query();
accept(Token.RPAREN);
return queryRest(select);
}
accept(Token.SELECT);
SQLSelectQueryBlock queryBlock = new SQLSelectQueryBlock();
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);
return queryRest(queryBlock);
}
protected void parseWhere(SQLSelectQueryBlock queryBlock) throws ParserException {
if (lexer.token() == Token.WHERE) {
lexer.nextToken();
queryBlock.setWhere(expr());
}
}
protected void parseGroupBy(SQLSelectQueryBlock queryBlock) throws ParserException {
if (lexer.token() == Token.GROUP) {
lexer.nextToken();
accept(Token.BY);
SQLSelectGroupByClause groupBy = new SQLSelectGroupByClause();
while (true) {
groupBy.getItems().add(expr());
if (lexer.token() != Token.COMMA) {
break;
}
lexer.nextToken();
}
if (lexer.token() == Token.HAVING) {
lexer.nextToken();
groupBy.setHaving(expr());
}
queryBlock.setGroupBy(groupBy);
} else if (lexer.token() == (Token.HAVING)) {
lexer.nextToken();
SQLSelectGroupByClause groupBy = new SQLSelectGroupByClause();
groupBy.setHaving(this.createExprParser().expr());
queryBlock.setGroupBy(groupBy);
}
}
protected void parseSelectList(SQLSelectQueryBlock queryBlock) throws ParserException {
queryBlock.getSelectList().add(new SQLSelectItem(expr(), as()));
while (lexer.token() == Token.COMMA) {
lexer.nextToken();
queryBlock.getSelectList().add(new SQLSelectItem(expr(), as()));
}
}
public void parseFrom(SQLSelectQueryBlock queryBlock) throws ParserException {
if (lexer.token() != Token.FROM) {
return;
}
lexer.nextToken();
queryBlock.setFrom(parseTableSource());
}
public SQLTableSource parseTableSource() throws ParserException {
if (lexer.token() == Token.LPAREN) {
lexer.nextToken();
SQLTableSource tableSource;
if (lexer.token() == Token.SELECT) {
SQLSelect select = select();
accept(Token.RPAREN);
queryRest(select.getQuery());
tableSource = new SQLSubqueryTableSource(select);
} else if (lexer.token() == Token.LPAREN) {
tableSource = parseTableSource();
accept(Token.RPAREN);
} else {
throw new ParserException("TODO");
}
return parseTableSourceRest(tableSource);
}
if (lexer.token() == Token.SELECT) {
throw new ParserException("TODO");
}
SQLExprTableSource tableReference = new SQLExprTableSource();
parseTableSourceQueryTableExpr(tableReference);
return parseTableSourceRest(tableReference);
}
private void parseTableSourceQueryTableExpr(SQLExprTableSource tableReference) throws ParserException {
if (lexer.token() == Token.LITERAL_ALIAS || lexer.token() == Token.IDENTIFIED || lexer.token() == Token.LITERAL_CHARS) {
tableReference.setExpr(this.createExprParser().name());
return;
}
tableReference.setExpr(expr());
}
protected SQLTableSource parseTableSourceRest(SQLTableSource tableSource) throws ParserException {
if ((tableSource.getAlias() == null) || (tableSource.getAlias().length() == 0)) {
if (lexer.token() != Token.LEFT && lexer.token() != Token.RIGHT && lexer.token() != Token.FULL) {
tableSource.setAlias(as());
}
}
SQLJoinTableSource.JoinType joinType = null;
if (lexer.token() == Token.LEFT) {
lexer.nextToken();
if (lexer.token() == Token.OUTER) {
lexer.nextToken();
}
accept(Token.JOIN);
joinType = SQLJoinTableSource.JoinType.LEFT_OUTER_JOIN;
} else if (lexer.token() == Token.RIGHT) {
lexer.nextToken();
if (lexer.token() == Token.OUTER) {
lexer.nextToken();
}
accept(Token.JOIN);
joinType = SQLJoinTableSource.JoinType.RIGHT_OUTER_JOIN;
} else if (lexer.token() == Token.FULL) {
lexer.nextToken();
if (lexer.token() == Token.OUTER) {
lexer.nextToken();
}
accept(Token.JOIN);
joinType = SQLJoinTableSource.JoinType.FULL_OUTER_JOIN;
} else if (lexer.token() == Token.INNER) {
lexer.nextToken();
accept(Token.JOIN);
joinType = SQLJoinTableSource.JoinType.INNER_JOIN;
} else if (lexer.token() == Token.JOIN) {
lexer.nextToken();
joinType = SQLJoinTableSource.JoinType.JOIN;
} else if (lexer.token() == Token.COMMA) {
lexer.nextToken();
joinType = SQLJoinTableSource.JoinType.COMMA;
}
if (joinType != null) {
SQLJoinTableSource join = new SQLJoinTableSource();
join.setLeft(tableSource);
join.setJoinType(joinType);
join.setRight(parseTableSource());
if (lexer.token() == Token.ON) {
lexer.nextToken();
join.setCondition(expr());
}
return parseTableSourceRest(join);
}
return tableSource;
}
public SQLExpr expr() {
return createExprParser().expr();
}
protected SQLExprParser createExprParser() {
return new SQLExprParser(lexer);
}
public SQLOrderBy parseOrderBy() throws ParserException {
return createExprParser().parseOrderBy();
}
public void acceptKeyword(String ident) {
if (lexer.token() == Token.IDENTIFIER && ident.equalsIgnoreCase(lexer.stringVal())) {
lexer.nextToken();
} else {
setErrorEndPos(lexer.pos());
throw new SQLParseException("syntax error, expect " + ident + ", actual " + lexer.token());
}
}
}