import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlUnionQuery; //导入依赖的package包/类
@Override
	public void statementParse(SchemaConfig schema, RouteResultset rrs, SQLStatement stmt) {
		SQLSelectStatement selectStmt = (SQLSelectStatement)stmt;
		SQLSelectQuery sqlSelectQuery = selectStmt.getSelect().getQuery();
		if(sqlSelectQuery instanceof MySqlSelectQueryBlock) {
			MySqlSelectQueryBlock mysqlSelectQuery = (MySqlSelectQueryBlock)selectStmt.getSelect().getQuery();

				 parseOrderAggGroupMysql(schema, stmt,rrs, mysqlSelectQuery);
				 //更改canRunInReadDB属性
				 if ((mysqlSelectQuery.isForUpdate() || mysqlSelectQuery.isLockInShareMode()) && rrs.isAutocommit() == false)
				 {
					 rrs.setCanRunInReadDB(false);
				 }

		} else if (sqlSelectQuery instanceof MySqlUnionQuery) { 
//			MySqlUnionQuery unionQuery = (MySqlUnionQuery)sqlSelectQuery;
//			MySqlSelectQueryBlock left = (MySqlSelectQueryBlock)unionQuery.getLeft();
//			MySqlSelectQueryBlock right = (MySqlSelectQueryBlock)unionQuery.getLeft();
//			System.out.println();
		}
	}
 

import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlUnionQuery; //导入依赖的package包/类
public static boolean isNoSharding(ServerConnection source, SQLSelectQuery sqlSelectQuery, SQLStatement selectStmt, String contextSchema, StringPtr sqlSchema)
        throws SQLException {
    if (sqlSelectQuery instanceof MySqlSelectQueryBlock) {
        MySqlSelectQueryBlock mySqlSelectQueryBlock = (MySqlSelectQueryBlock) sqlSelectQuery;
        if (!isNoSharding(source, mySqlSelectQueryBlock.getFrom(), selectStmt, contextSchema, sqlSchema)) {
            return false;
        }
        if (mySqlSelectQueryBlock.getWhere() != null && !SchemaUtil.isNoSharding(source, mySqlSelectQueryBlock.getWhere(), contextSchema, sqlSchema)) {
            return false;
        }
        for (SQLSelectItem selectItem : mySqlSelectQueryBlock.getSelectList()) {
            if (!SchemaUtil.isNoSharding(source, selectItem.getExpr(), contextSchema, sqlSchema)) {
                return false;
            }
        }
        return true;
    } else if (sqlSelectQuery instanceof MySqlUnionQuery) {
        return isNoSharding(source, (MySqlUnionQuery) sqlSelectQuery, selectStmt, contextSchema, sqlSchema);
    } else {
        return false;
    }
}
 

import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlUnionQuery; //导入依赖的package包/类
public SQLUnionQuery unionRest(SQLUnionQuery union) {
    if (lexer.token() == Token.LIMIT) {
        MySqlUnionQuery mysqlUnionQuery = (MySqlUnionQuery) union;
        mysqlUnionQuery.setLimit(parseLimit());
    }
    return super.unionRest(union);
}
 

import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlUnionQuery; //导入依赖的package包/类
public void visit(SQLSelectQuery node) {
    if (node instanceof MySqlSelectQueryBlock) {
        visit((MySqlSelectQueryBlock) node);
    } else if (node instanceof MySqlUnionQuery) {
        visit((MySqlUnionQuery) node);
    }
}
 

import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlUnionQuery; //导入依赖的package包/类
protected void parseStatement(ParseResult result, ExecutePlan plan, SQLSelectStatement statement){
     // 单库单表
     if (plan.getSqlList().size() <= 1){
         return;
     }

     SQLSelectQuery sqlSelectQuery = statement.getSelect().getQuery();
     if(sqlSelectQuery instanceof MySqlSelectQueryBlock) {
         // mysql查询
         parseMysqlQueary(result, plan, (MySqlSelectQueryBlock) sqlSelectQuery);
     } else if (sqlSelectQuery instanceof MySqlUnionQuery) {
         throw new BayMaxException("Union暂不支持发送到多库多表上执行，只能在单库单表执行！");
         // TODO 测试
/*
MySqlUnionQuery unionQuery = (MySqlUnionQuery)sqlSelectQuery;
         SQLSelectQuery left = unionQuery.getLeft();
         SQLSelectQuery right = unionQuery.getLeft();
         if (left instanceof MySqlSelectQueryBlock){
             parseMysqlQueary(result, plan, (MySqlSelectQueryBlock) left);
         }
         if (right instanceof MySqlSelectQueryBlock){
             parseMysqlQueary(result, plan, (MySqlSelectQueryBlock) right);
         }
         */
         //if (left.getFrom().getAlias().equalsIgnoreCase(plan.getSqlList().get(0).getLogicTableName())){

         //}
     }
 }
 

import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlUnionQuery; //导入依赖的package包/类
protected MySqlUnionQuery createSQLUnionQuery() {
    return new MySqlUnionQuery();
}