在postgresql函数中捕获select查询返回值并使用它

我想执行这个函数。但它得到了错误的回答

错误：

在“：”处或附近出现语法错误

第7行：选择result:=MAX（路径\历史\ id）作为从…进入结果的路径

在这个函数中，我想：

执行

select with（MAX）

将从表中返回最大id

捕捉该值（它是一个整数值）

将该值放入最后一个select查询where条件

我在postgresql中找不到这样做的方法

CREATE OR REPLACE FUNCTION memcache(IN starting_point_p1 character varying, IN ending_point_p1 character varying)

RETURNS TABLE(path integer, movement_id_out integer, object_id_fk_out integer, path_history_id_fk_out integer, walking_distance_out real, angel_out real, direction_out character varying, time_stamp_out timestamp without time zone, x_coordinate_out real, y_coordinate_out real, z_coordinate_out real) AS
$BODY$
    DECLARE result int;
    BEGIN
    
    select result:=MAX(path_history_id)as path INTO result from path_history_info where starting_point=starting_point_p1 and ending_point =ending_point_p1 and achieve='1';
    return query
    select * from movement_info where path_history_id_fk=result;    
    END;
    $BODY$
  LANGUAGE plpgsql

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语法错误

函数中的第一个查询需要更改如下：

select MAX(path_history_id)as path INTO result 
  from path_history_info 
    where starting_point=starting_point_p1 
     and ending_point =ending_point_p1 and achieve='1';

单个查询

实际上，您不需要为此使用存储过程。单个查询可以获得相同的结果

select * from movement_info where path_history_id_fk = 
 (SELECT MAX(path_history_id) FROM path_history_info 
    where starting_point=starting_point_p1 
     and ending_point =ending_point_p1 and achieve='1';