Postgres SQL游标

Question

我是SQL Server的人，我需要在Postgres中编写一些动态SQL。这就是我需要的。动态SQL将取决于此查询生成的整数：

SELECT local_channel_id
FROM d_channels dc
INNER JOIN channel c ON c.id = dc.channel_id
                     AND c.name LIKE '%__Achv'

使用这个，我需要在下面的查询中构建并执行一个select和后续的union选择，用下面的{X}替换上面查询产生的值（4个地方）：

SELECT
    dmc.message_id,
    dmm.received_date,
    dmm.server_id,
    dc.channel_id,
    dmcm."SOURCE",
    dmcm."TYPE",
    dmm.status,
    dmc.content
FROM 
    d_mc{X} dmc
INNER JOIN 
    d_mm{X} dmm ON dmc.message_id = dmm.message_id
INNER JOIN 
    d_channels dc ON dc.local_channel_id = {X}
INNER JOIN 
    d_mcm{X} dmcm ON dmcm.message_id = dmc.message_id
                  AND dmcm.metadata_id = 0
WHERE 
    dmm.connector_name = 'Source'
    AND dmc.content_type = 1 --Raw
    AND date(dmm.received_date) + interval '7' < now()

有人可以帮忙吗？对于Postgres来说，我真的很无能为力。