OraclevsPostgreSQLDevelop(17)-ARRAY

PostgreSQL可用ARRAY来替代Oracle中的collection type,包括associative array/Varrays (Variable-Size Arrays)/Nested Tables

10年积累的成都网站制作、做网站经验,可以快速应对客户对网站的新想法和需求。提供各种问题对应的解决方案。让选择我们的客户得到更好、更有力的网络服务。我虽然不认识你,你也不认识我。但先网站设计后付款的网站建设流程,更有南安免费网站建设让你可以放心的选择与我们合作。

Oracle
简单举个例子:

drop table if exists employee;
create table employee(id int,name varchar(30),department varchar(30),salary float);
insert into employee(id,name,department,salary) select rownum,substrb(object_name,1,30),substrb(object_name,1,30),1000 from dba_objects;
DECLARE
   TYPE EmpTabTyp IS TABLE OF employee%ROWTYPE
      INDEX BY PLS_INTEGER;
   emp_tab EmpTabTyp;
   i int := 0;
BEGIN
   /* Retrieve employee record. */
   for c1 in (select * from employee) loop
     emp_tab(i).id := c1.id;
     emp_tab(i).name := c1.name;
     emp_tab(i).department := c1.department;
     emp_tab(i).salary := c1.salary;
     i := i+1;
   end loop;
   -- SELECT * INTO emp_tab(100) FROM employee WHERE id = 100;
END;
/

更简单的做法是使用bulk collection

DECLARE
   TYPE EmpTabTyp IS TABLE OF employee%ROWTYPE
      INDEX BY PLS_INTEGER;
   emp_tab EmpTabTyp;
   i int := 0;
BEGIN
   /* Retrieve employee record. */
   select id,name,department,salary bulk collect into emp_tab from employee;
END;
/

PostgreSQL
使用ARRAY


drop type record_of_employee;
CREATE TYPE record_of_employee AS (id int,name varchar(30),department varchar(30),salary float);
do
$$
declare
  employees record_of_employee[];
begin
  select array_agg(employee) into employees from employee limit 1;
  raise notice 'id is %',employees[1].id;
  raise notice 'name is %',employees[1].name;
end
$$;

对于Associative array indexed by string,PG的数组则替代不了.

DECLARE
  -- Associative array indexed by string:
  TYPE population IS TABLE OF NUMBER  -- Associative array type
    INDEX BY VARCHAR2(64);            --  indexed by string
...

参考资料
PL/SQL Collections and Records
Oracle PL/SQL Collections: Varrays, Nested & Index by Tables
Collections in Oracle PL/SQL
Working with Collections
Take a Dip into PostgreSQL Arrays


新闻名称:OraclevsPostgreSQLDevelop(17)-ARRAY
当前链接:http://lszwz.com/article/iejjeg.html

其他资讯

售后响应及时

7×24小时客服热线

数据备份

更安全、更高效、更稳定

价格公道精准

项目经理精准报价不弄虚作假

合作无风险

重合同讲信誉,无效全额退款