Postgresql：for循环遍历表中的每个ID答案

【问题标题】：Postresql: for loop over every id in tablePostgresql：for循环遍历表中的每个ID
【发布时间】：2021-03-05 01:07:09
【问题描述】：

我有以下脚本：

do
$do$
begin
    FOR i IN 1..450 LOOP
        if (1= (select count (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i)
        and 1= (select count (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'OWNER') )
            then raise notice 'id % :  owner only', i;
        elsif(0< (select count (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i) )
            then 
                if(not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'APPLICANT'))
                    then raise notice 'id % :  adding applicant role', i; insert into document_configuration_role values (i, 'APPLICANT');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'EXPERT'))
                    then raise notice 'id % :  adding expert role', i; insert into document_configuration_role values (i, 'EXPERT');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'OWNER'))
                    then raise notice 'id % :  adding owner role', i; insert into document_configuration_role values (i, 'OWNER');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'ADMIN'))
                    then raise notice 'id % :  adding admin role', i; insert into document_configuration_role values (i, 'ADMIN');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'HEAD'))
                    then raise notice 'id % :  adding head role', i; insert into document_configuration_role values (i, 'HEAD');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'EMPLOYEE'))
                    then raise notice 'id % :  adding employee role', i; insert into document_configuration_role values (i, 'EMPLOYEE');
                end if;
                if(  EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'RECOMMENDER'))
                    then raise notice 'id % :  removing recommender role', i; delete from document_configuration_role dc where dc.document_configuration_id = i and dc.role_name like 'RECOMMENDER';
                end if;
                if(  6 = (select count (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i))
                    then raise notice 'id % :  all roles assigned', i; 
                end if;
        else
            raise notice 'id % :  not existing', i;
        end if;
    end loop;
end;
$do$

我在这里声明了一个硬编码的迭代器（从1到450），但我只想通过document_configuration_role.document_configuration_id进行迭代，如何实现？

我尝试了类似下面的声明我记录：

do
$do$
declare i record;
begin
    FOR i IN (select dcr2.document_configuration_id from document_configuration_role dcr2) LOOP
        if (1= (select count (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i)
        and 1= (select count (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'OWNER') )
            then raise notice 'id % :  owner only', i;
        elsif(0< (select count (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i) )
            then 
                if(not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'APPLICANT'))
                    then raise notice 'id % :  adding applicant role', i; insert into document_configuration_role values (i, 'APPLICANT');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'EXPERT'))
                    then raise notice 'id % :  adding expert role', i; insert into document_configuration_role values (i, 'EXPERT');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'OWNER'))
                    then raise notice 'id % :  adding owner role', i; insert into document_configuration_role values (i, 'OWNER');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'ADMIN'))
                    then raise notice 'id % :  adding admin role', i; insert into document_configuration_role values (i, 'ADMIN');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'HEAD'))
                    then raise notice 'id % :  adding head role', i; insert into document_configuration_role values (i, 'HEAD');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'EMPLOYEE'))
                    then raise notice 'id % :  adding employee role', i; insert into document_configuration_role values (i, 'EMPLOYEE');
                end if;
                if(  EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'RECOMMENDER'))
                    then raise notice 'id % :  removing recommender role', i; delete from document_configuration_role dc where dc.document_configuration_id = i and dc.role_name like 'RECOMMENDER';
                end if;
                if(  6 = (select count (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i))
                    then raise notice 'id % :  all roles assigned', i; 
                end if;
        else
            raise notice 'id % :  not existing', i;
        end if;
    end loop;
end;
$do$

但它显示错误：

SQL 错误 [42883]：错误：运算符不存在：bigint = 记录
提示：没有运算符匹配给定的名称和参数类型。你可能需要添加显式类型转换。其中：PL/pgSQL 函数 IF 处的 inline_code_block 第 5 行

您对如何仅通过表中的 id 进行迭代有什么建议吗？

【问题讨论】：

是否 select dcr2.document_configuration_id from document_configuration_role dcr2 返回缩放器值？有什么价值？ select document_configuration_id 的数据类型是什么？
您已将i 声明为record。为了获得document_configuration_id，您需要执行i.document_configuration_id。如果您只需要使用document_configuration_id，则将i 声明为整数。

标签： sql postgresql loops

【解决方案1】：

您只是将查询中的 configuration_id 提取到 i 中。

尝试将 i 声明为 bigint 而不是记录。

【讨论】：

【解决方案2】：

如果您想遍历 document_configuration_role 中的所有 document_configuration_id（分配给 i），则使用 document_configuration_id 的数据类型声明 i（我假设它为 bigint）。 p>

do $$
declare i bigint;

begin
FOR i IN
   select dcr2.document_configuration_id from document_configuration_role dcr2
LOOP  
        if (1= (select count (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i)
        and 1= (select count (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'OWNER') )
            then raise notice 'id % :  owner only', i;
        elsif(0< (select count (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i) )
            then 
                if(not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'APPLICANT'))
                    then raise notice 'id % :  adding applicant role', i; insert into document_configuration_role values (i, 'APPLICANT');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'EXPERT'))
                    then raise notice 'id % :  adding expert role', i; insert into document_configuration_role values (i, 'EXPERT');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'OWNER'))
                    then raise notice 'id % :  adding owner role', i; insert into document_configuration_role values (i, 'OWNER');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'ADMIN'))
                    then raise notice 'id % :  adding admin role', i; insert into document_configuration_role values (i, 'ADMIN');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'HEAD'))
                    then raise notice 'id % :  adding head role', i; insert into document_configuration_role values (i, 'HEAD');
                end if;
                if( not EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'EMPLOYEE'))
                    then raise notice 'id % :  adding employee role', i; insert into document_configuration_role values (i, 'EMPLOYEE');
                end if;
                if(  EXISTS (select (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i and  dcr.role_name like 'RECOMMENDER'))
                    then raise notice 'id % :  removing recommender role', i; delete from document_configuration_role dc where dc.document_configuration_id = i and dc.role_name like 'RECOMMENDER';
                end if;
                if(  6 = (select count (dcr.role_name) from document_configuration_role dcr where dcr.document_configuration_id = i))
                    then raise notice 'id % :  all roles assigned', i; 
                end if;
        else
            raise notice 'id % :  not existing', i;
        end if;
    end loop;
end;$$

【讨论】：