SQLSelect.java

/*
 * Copyright 1999-2017 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.ast.statement;

import java.util.ArrayList;
import java.util.List;

import com.alibaba.druid.sql.SQLUtils;
import com.alibaba.druid.sql.ast.SQLHint;
import com.alibaba.druid.sql.ast.SQLObject;
import com.alibaba.druid.sql.ast.SQLObjectImpl;
import com.alibaba.druid.sql.ast.SQLOrderBy;
import com.alibaba.druid.sql.ast.SQLStatement;
import com.alibaba.druid.sql.visitor.SQLASTVisitor;

public class SQLSelect extends SQLObjectImpl {

    protected SQLWithSubqueryClause withSubQuery;
    protected SQLSelectQuery        query;
    protected SQLOrderBy            orderBy;

    protected List<SQLHint>           hints;

    public SQLSelect(){

    }

    public List<SQLHint> getHints() {
        if (hints == null) {
            hints = new ArrayList<SQLHint>(2);
        }
        return hints;
    }
    
    public int getHintsSize() {
        if (hints == null) {
            return 0;
        }
        return hints.size();
    }

    public SQLSelect(SQLSelectQuery query){
        this.setQuery(query);
    }

    public SQLWithSubqueryClause getWithSubQuery() {
        return withSubQuery;
    }

    public void setWithSubQuery(SQLWithSubqueryClause withSubQuery) {
        this.withSubQuery = withSubQuery;
    }

    public SQLSelectQuery getQuery() {
        return this.query;
    }

    public void setQuery(SQLSelectQuery query) {
        if (query != null) {
            query.setParent(this);
        }
        this.query = query;
    }

    public SQLOrderBy getOrderBy() {
        return this.orderBy;
    }

    public void setOrderBy(SQLOrderBy orderBy) {
        this.orderBy = orderBy;
    }

    protected void accept0(SQLASTVisitor visitor) {
        if (visitor.visit(this)) {
            acceptChild(visitor, this.query);
            acceptChild(visitor, this.orderBy);
            acceptChild(visitor, this.hints);
        }

        visitor.endVisit(this);
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((orderBy == null) ? 0 : orderBy.hashCode());
        result = prime * result + ((query == null) ? 0 : query.hashCode());
        result = prime * result + ((withSubQuery == null) ? 0 : withSubQuery.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) return true;
        if (obj == null) return false;
        if (getClass() != obj.getClass()) return false;
        SQLSelect other = (SQLSelect) obj;
        if (orderBy == null) {
            if (other.orderBy != null) return false;
        } else if (!orderBy.equals(other.orderBy)) return false;
        if (query == null) {
            if (other.query != null) return false;
        } else if (!query.equals(other.query)) return false;
        if (withSubQuery == null) {
            if (other.withSubQuery != null) return false;
        } else if (!withSubQuery.equals(other.withSubQuery)) return false;
        return true;
    }

    public String toString() {
        SQLObject parent = this.getParent();
        if (parent instanceof SQLStatement) {
            String dbType = ((SQLStatement) parent).getDbType();
            
            if (dbType != null) {
                return SQLUtils.toSQLString(this, dbType);
            }
        }
        
        return super.toString();
    }

    public SQLSelect clone() {
        SQLSelect clone = new SQLSelect();

        clone.withSubQuery = this.withSubQuery;
        clone.query = this.query;
        clone.orderBy = this.orderBy;
        clone.hints = this.hints;

        return clone;
    }
}