postgresql函数：满足特定格式的表及指定日期前的删除

-- 一、现有函数
-- 1、现有函数调用
select "ap"."delete_analysis_backup"('ap');
-- 2、函数内容
CREATE OR REPLACE FUNCTION "ap"."delete_analysis_backup"("schema_name" varchar)
  RETURNS "pg_catalog"."void" AS $BODY$ DECLARE
    row_tag VARCHAR ( 200 );
BEGIN-- Created by Liu Jinhui
    FOR row_tag IN (
        SELECT TABLE_NAME
        FROM
            (
            SELECT
                tablename AS TABLE_NAME,
                ( regexp_match ( tablename, 'analysis_[a-z,_]+_([0-9]{8,8})' ) ) [ 1 ] AS table_backup_time
            FROM
                pg_tables
            WHERE
                schemaname = schema_name
                AND tablename SIMILAR TO 'analysis_[a-z,_]+_[0-9]{8,12}'
            ) A
        WHERE
            DATE_TRUNC( 'day', to_date( A.table_backup_time, 'yyyyMMdd' ) ) < DATE_TRUNC( 'day', now( ) + '-7 day' )
        )
        LOOP
        RAISE notice'表名为：%',
        row_tag;
    EXECUTE concat ( 'drop table ', SCHEMA_NAME, '.', row_tag );END LOOP;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100
-- 二、依赖项
-- 要求：删除ods包含gyy的表，删除一个月
-- 函数头：del_special_struct(schema_name,period_saved,remark)
-- 调用：
select ods.del_special_struct('ap','1 days','删除以往的分析对象模型')
select ods.del_special_struct('ods','31 days','删除一个月之前的gyy物理备份表')-- 三、过程
-- 要求：删除ods包含gyy的表，删除一个月
-- 函数头：del_special_struct(schema_name,period_saved,remark)
-- 调用：
select ods.del_special_struct('ap','1 days','删除以往的分析对象模型');
select ods.del_special_struct('ods','31 days','删除一个月之前的gyy物理备份表');
-- 1、ap
CREATE OR REPLACE FUNCTION ods.del_special_struct(schema_name varchar,period_saved varchar,remark varchar)
  RETURNS "pg_catalog"."void" AS $BODY$ DECLARE
BEGIN
    if schema_name = 'ap' then
        EXECUTE select "ap"."delete_analysis_backup"('ap');
    else
        -- gyy删除一个月前的表
    end if;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100-- 2、ods的管易云删除逻辑
-- （1）查询出所有满足条件的表
select tablename,to_char(date(concat('20',split_part(tablename,'_20',2))),'yyyymmdd') as mon_day
from pg_tables
where schemaname = 'ods'
and tablename SIMILAR TO 'ods_trade_[a-z,_]+gyy_[2022][0-9,_]+'
and to_char(date(concat('20',split_part(tablename,'_20',2))),'yyyymmdd') < to_char(date_trunc('day',now())+'-30 days','yyyymmdd')
-- （2）删除表CREATE OR REPLACE FUNCTION ods.del_special_struct(schema_name varchar,period_saved varchar,remark varchar)
  RETURNS "pg_catalog"."void" AS $BODY$ DECLARE
    DECLARE arrat_t varchar[];
    DECLARE dt_split INTERVAL='-' ||period_saved;
    DECLARE tb_each VARCHAR;
    DECLARE res VARCHAR;
  BEGIN
        if schema_name = 'ap' then
            select ap.delete_analysis_backup('ap') into res;
        else
            -- gyy删除一个月前的表
            -- 如果存在分区表，则删除对应的物理表
            select array(
                select tablename from (
                    select tablename,to_char(date(concat('20',split_part(tablename,'_20',2))),'yyyymmdd') as mon_day
                    from pg_tables
                    where schemaname = 'ods'
                    and tablename SIMILAR TO 'ods_trade_[a-z,_]+gyy_[2022][0-9,_]+'
                    and to_char(date(concat('202',split_part(tablename,'_202',2))),'yyyymmdd') < to_char(date_trunc('day',now())+dt_split,'yyyymmdd')
                ) all_table) into arrat_t;
            foreach tb_each in array arrat_t
            loop
                EXECUTE format('DROP TABLE IF EXISTS %s.%s', schema_name,tb_each);
            end loop;
        end if;
  END
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

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