使用pl/sql记录类型显示仓库中产品的平均数量

我需要显示一个产品名称列表，其中ID在100-105之间，所有仓库的平均数量，以及产品数量最多的仓库的名称（对于每个产品）。唯一的问题是平均值（f_avg）不起作用，相反，f_avg显示的是最大数量的产品

输出示例为：

金斯敦HyperX捕食者平均产品：173种，主要分布在旧金山

英特尔至强E5-2687W V4平均产品：90种主要在多伦多

EVGA 12G-P4-3992-KR平均产品：178种主要分布在旧金山

这是我的代码，任何人都知道平均值有什么问题，我也有一个错误：

ORA-00979:不是第3行表达式ORA-06512:的组

ORA-06512：在第14行

ORA-06512：“SYS.DBMS_SQL”，第1721行

如果你不改变代码的结构会更好，但最重要的是，我需要使用记录类型

 DECLARE
 CURSOR cur_emp_detail IS
   SELECT pproduct_name, avg_quantity, (SELECT w.warehouse_name FROM warehouses w WHERE w.warehouse_id = (SELECT i.warehouse_id FROM inventories i join products p on p.product_id = i.product_id HAVING i.quantity = MAX (i.quantity))) as ware
    FROM (SELECT p.product_name as pproduct_name, AVG (i.quantity) AS avg_quantity
                       FROM products p JOIN inventories i ON p.product_id = i.product_id
                      WHERE (p.product_id BETWEEN 100 AND 105)
                   GROUP BY p.product_name);
 TYPE type_record_type IS RECORD (
   emp_f_name products.product_name%TYPE,
   emp_avg inventories.quantity%type,
   emp_wh warehouses.warehouse_name%type);
 emp_rec_type type_record_type;
     BEGIN
     OPEN cur_emp_detail;
     LOOP
         FETCH cur_emp_detail INTO emp_rec_type;
         EXIT WHEN cur_emp_detail%NOTFOUND;
         dbms_output.Put_line(emp_rec_type.emp_f_name||' average product: '||emp_rec_type.emp_avg||' mostly found in '||emp_rec_type.emp_wh);
     END LOOP;
     CLOSE cur_emp_detail;
 END;
 / 

---

使用

批量收集

比在游标中循环要高效得多。这减少了上下文切换的数量，并且仍然允许您将每一行作为记录类型引用

DECLARE
    TYPE product_rec IS RECORD
    (
        emp_f_name    products.product_name%TYPE,
        emp_avg       inventories.quantity%TYPE,
        emp_wh        warehouses.warehouse_name%TYPE
    );

    TYPE product_t IS TABLE OF product_rec;

    l_products   product_t;
BEGIN
    SELECT product_name, avg_quantity, warehouse_name
      BULK COLLECT INTO l_products
      FROM (SELECT p.product_name,
                   AVG (i.quantity) OVER (PARTITION BY p.product_id)                              AS avg_quantity,
                   w.warehouse_name,
                   ROW_NUMBER ()
                       OVER (PARTITION BY PRODUCT_NAME ORDER BY QUANTITY DESC, WAREHOUSE_NAME)    warehouse_order
              FROM products  p
                   JOIN inventories i ON p.product_id = i.product_id
                   JOIN warehouses w ON i.warehouse_id = w.warehouse_id
             WHERE (p.product_id BETWEEN 100 AND 105))
     WHERE warehouse_order = 1;

    FOR i IN 1 .. l_products.COUNT
    LOOP
        DBMS_OUTPUT.Put_line (
               l_products (i).emp_f_name
            || ' average product: '
            || l_products (i).emp_avg
            || ' mostly found in '
            || l_products (i).emp_wh);
    END LOOP;
END;
/

---

使用

批量收集

比在游标中循环要高效得多。这减少了上下文切换的数量，并且仍然允许您将每一行作为记录类型引用

DECLARE
    TYPE product_rec IS RECORD
    (
        emp_f_name    products.product_name%TYPE,
        emp_avg       inventories.quantity%TYPE,
        emp_wh        warehouses.warehouse_name%TYPE
    );

    TYPE product_t IS TABLE OF product_rec;

    l_products   product_t;
BEGIN
    SELECT product_name, avg_quantity, warehouse_name
      BULK COLLECT INTO l_products
      FROM (SELECT p.product_name,
                   AVG (i.quantity) OVER (PARTITION BY p.product_id)                              AS avg_quantity,
                   w.warehouse_name,
                   ROW_NUMBER ()
                       OVER (PARTITION BY PRODUCT_NAME ORDER BY QUANTITY DESC, WAREHOUSE_NAME)    warehouse_order
              FROM products  p
                   JOIN inventories i ON p.product_id = i.product_id
                   JOIN warehouses w ON i.warehouse_id = w.warehouse_id
             WHERE (p.product_id BETWEEN 100 AND 105))
     WHERE warehouse_order = 1;

    FOR i IN 1 .. l_products.COUNT
    LOOP
        DBMS_OUTPUT.Put_line (
               l_products (i).emp_f_name
            || ' average product: '
            || l_products (i).emp_avg
            || ' mostly found in '
            || l_products (i).emp_wh);
    END LOOP;
END;
/

---

我建议使用如下子查询的结构化方法

1）生成明细数据的子查询：产品、仓库和数量

请注意，我假设表

存货

有一个主键

产品标识，仓库标识

，如果没有主键，您必须通过分组

产品标识，仓库标识

额外聚合数量

SELECT p.product_name, w.warehouse_name, i.quantity 
 FROM products p 
 JOIN inventories i ON p.product_id = i.product_id
 LEFT OUTER JOIN warehouses w ON w.warehouse_id =  i.warehouse_id
 WHERE (p.product_id BETWEEN 100 AND 105);
 
PRODUCT_ WAREHOUSE_NAM   QUANTITY
-------- ------------- ----------
Kingston San Francisco        173
EVGA     Toronto              178
Intel    Toronto               70
Intel    Toronto               90
Kingston Toronto              173

2）使用分析函数计算平均数量和仓库等级

with prd as (
 SELECT p.product_name, w.warehouse_name, i.quantity 
 FROM products p 
 JOIN inventories i ON p.product_id = i.product_id
 LEFT OUTER JOIN warehouses w ON w.warehouse_id =  i.warehouse_id
 WHERE (p.product_id BETWEEN 100 AND 105)
),
prd2 as (
select 
  PRODUCT_NAME, WAREHOUSE_NAME, QUANTITY,
  avg(QUANTITY) over (partition by PRODUCT_NAME) avg_quantity,
  row_number() over (partition by PRODUCT_NAME order by QUANTITY desc, WAREHOUSE_NAME) warehouse_order
from prd)
select * from prd2;

PRODUCT_ WAREHOUSE_NAM   QUANTITY AVG_QUANTITY WAREHOUSE_ORDER
-------- ------------- ---------- ------------ ---------------
EVGA     Toronto              178          178               1
Intel    Toronto               90           80               1
Intel    Toronto               70           80               2
Kingston San Francisco        173          173               1
Kingston Toronto              173          173               2

3）仅获取每个产品的顶级仓库记录

with prd as (
 SELECT p.product_name, w.warehouse_name, i.quantity 
 FROM products p 
 JOIN inventories i ON p.product_id = i.product_id
 LEFT OUTER JOIN warehouses w ON w.warehouse_id =  i.warehouse_id
 WHERE (p.product_id BETWEEN 100 AND 105)
),
prd2 as (
select 
  PRODUCT_NAME, WAREHOUSE_NAME, QUANTITY,
  avg(QUANTITY) over (partition by PRODUCT_NAME) avg_quantity,
  row_number() over (partition by PRODUCT_NAME order by QUANTITY desc, WAREHOUSE_NAME) warehouse_order
from prd)
select PRODUCT_NAME, WAREHOUSE_NAME, AVG_QUANTITY 
from prd2
where warehouse_order = 1; 

PRODUCT_ WAREHOUSE_NAM AVG_QUANTITY
-------- ------------- ------------
EVGA     Toronto                178
Intel    Toronto                 80
Kingston San Francisco          173

如果您坚持使用游标和记录类型，那么核心逻辑就是上面的查询

注二：

使用

MAX（quantity）

获得顶级记录是一种幼稚的方法，如果你有联系，那么这种方法会失败，即MAX等于多条记录！ 请参阅我的实现，其中，如果是领带，则显示具有较低名称的仓库

 order by QUANTITY desc, WAREHOUSE_NAME 

可以按

NAME

s进行分组，但如果有更多同名产品，则分组失败-通常按

ID

s进行分组

样本数据

create table products as
select 100 product_id, 'Kingston' product_name from dual union all
select 101 product_id, 'Intel ' product_name from dual union all
select 102 product_id, 'EVGA  ' product_name from dual;

create table inventories as
select 100 product_id, 173 quantity, 1 warehouse_id from dual union all
select 100 product_id, 173 quantity, 2 warehouse_id from dual union all
select 101 product_id, 90 quantity, 2 warehouse_id from dual union all
select 101 product_id, 70 quantity, 2 warehouse_id from dual union all
select 102 product_id, 178 quantity, 2 warehouse_id from dual;

create table warehouses as
select 1 warehouse_id, 'San Francisco' warehouse_name from dual union all
select 2 warehouse_id, 'Toronto' warehouse_name from dual;

---

我建议使用如下子查询的结构化方法

1）生成明细数据的子查询：产品、仓库和数量

请注意，我假设表

存货

有一个主键

产品标识，仓库标识

，如果没有主键，您必须通过分组

产品标识，仓库标识

额外聚合数量

SELECT p.product_name, w.warehouse_name, i.quantity 
 FROM products p 
 JOIN inventories i ON p.product_id = i.product_id
 LEFT OUTER JOIN warehouses w ON w.warehouse_id =  i.warehouse_id
 WHERE (p.product_id BETWEEN 100 AND 105);
 
PRODUCT_ WAREHOUSE_NAM   QUANTITY
-------- ------------- ----------
Kingston San Francisco        173
EVGA     Toronto              178
Intel    Toronto               70
Intel    Toronto               90
Kingston Toronto              173

2）使用分析函数计算平均数量和仓库等级

with prd as (
 SELECT p.product_name, w.warehouse_name, i.quantity 
 FROM products p 
 JOIN inventories i ON p.product_id = i.product_id
 LEFT OUTER JOIN warehouses w ON w.warehouse_id =  i.warehouse_id
 WHERE (p.product_id BETWEEN 100 AND 105)
),
prd2 as (
select 
  PRODUCT_NAME, WAREHOUSE_NAME, QUANTITY,
  avg(QUANTITY) over (partition by PRODUCT_NAME) avg_quantity,
  row_number() over (partition by PRODUCT_NAME order by QUANTITY desc, WAREHOUSE_NAME) warehouse_order
from prd)
select * from prd2;

PRODUCT_ WAREHOUSE_NAM   QUANTITY AVG_QUANTITY WAREHOUSE_ORDER
-------- ------------- ---------- ------------ ---------------
EVGA     Toronto              178          178               1
Intel    Toronto               90           80               1
Intel    Toronto               70           80               2
Kingston San Francisco        173          173               1
Kingston Toronto              173          173               2

3）仅获取每个产品的顶级仓库记录

with prd as (
 SELECT p.product_name, w.warehouse_name, i.quantity 
 FROM products p 
 JOIN inventories i ON p.product_id = i.product_id
 LEFT OUTER JOIN warehouses w ON w.warehouse_id =  i.warehouse_id
 WHERE (p.product_id BETWEEN 100 AND 105)
),
prd2 as (
select 
  PRODUCT_NAME, WAREHOUSE_NAME, QUANTITY,
  avg(QUANTITY) over (partition by PRODUCT_NAME) avg_quantity,
  row_number() over (partition by PRODUCT_NAME order by QUANTITY desc, WAREHOUSE_NAME) warehouse_order
from prd)
select PRODUCT_NAME, WAREHOUSE_NAME, AVG_QUANTITY 
from prd2
where warehouse_order = 1; 

PRODUCT_ WAREHOUSE_NAM AVG_QUANTITY
-------- ------------- ------------
EVGA     Toronto                178
Intel    Toronto                 80
Kingston San Francisco          173

如果您坚持使用游标和记录类型，那么核心逻辑就是上面的查询

注二：

使用

MAX（quantity）

获得顶级记录是一种幼稚的方法，如果你有联系，那么这种方法会失败，即MAX等于多条记录！ 请参阅我的实现，其中，如果是领带，则显示具有较低名称的仓库

 order by QUANTITY desc, WAREHOUSE_NAME 

可以按

NAME

s进行分组，但如果有更多同名产品，则分组失败-通常按

ID

s进行分组

样本数据

create table products as
select 100 product_id, 'Kingston' product_name from dual union all
select 101 product_id, 'Intel ' product_name from dual union all
select 102 product_id, 'EVGA  ' product_name from dual;

create table inventories as
select 100 product_id, 173 quantity, 1 warehouse_id from dual union all
select 100 product_id, 173 quantity, 2 warehouse_id from dual union all
select 101 product_id, 90 quantity, 2 warehouse_id from dual union all
select 101 product_id, 70 quantity, 2 warehouse_id from dual union all
select 102 product_id, 178 quantity, 2 warehouse_id from dual;

create table warehouses as
select 1 warehouse_id, 'San Francisco' warehouse_name from dual union all
select 2 warehouse_id, 'Toronto' warehouse_name from dual;

---

值得一提的是，大容量收集会消耗更多内存，这取决于您可能遇到错误ORA-04030或ORA-04031的数据量。在这种情况下，您可以考虑使用代码<代码>限制>代码>批量收集到 <代码>批量收集< /代码>增加复杂性，如果您期望的数据集不大，那么正常循环总是更好的。仅选择了~5种产品的信息，因此<10行不应占用太多内存。尽管在子查询中添加了

GROUP BY i.warehouse\u id

，但仍会失败，因为

ORA-00979:没有GROUP BY表达式

-

具有i.quantity=MAX（i.quantity）不允许使用

，因为

i.quantity

不是

分组依据

列。简单的自我测试。谢谢@marmite。我更新了查询以使用类似于您的查询。值得一提的是，批量收集会消耗更多内存，这取决于您可能遇到错误ORA-04030或ORA-04031的数据量。在这种情况下，您可以考虑使用代码<代码>限制>代码>批量收集到 <代码>批量收集< /代码>增加复杂性，如果您期望的数据集不大，那么正常循环总是更好的。仅选择了~5种产品的信息，因此<10行不应占用太多内存。尽管在子查询中添加了

GROUP BY i.warehouse\u id

，但仍会失败，因为

ORA-00979:没有GROUP BY表达式

-

具有i.quantity=MAX（i.quantity）不允许使用

，因为

i.quantity

不是

分组依据

列。简单的自我测试。谢谢@marmite。我更新了查询以使用类似于您的查询。