WHERE子句postgres中的SELECT问题

Question

I'm trying to create a table using these commands:

SELECT
    data_req,
    count(servico) as qtdeServico,
    count(metodo) as qtdeMetodo,
    consumerid,
    metodo,
    status_metodo,
    servico,
    sum(tempo_req)
INTO
    consolidado
FROM 
    requisicoes AS r
WHERE 
    r.data_req > SELECT MAX(c.data_req) FROM consolidado c  
GROUP BY 
    data_req, consumerid, metodo, status_metodo, servico;

Unfortunately I'm getting an error at the select clause inside where. I'm using postgres.

Any suggestions? Thanks in advance.

Answer 1

Your query has numerous idiosyncrasies. The following would be more correct syntax:

create table consolidado as 
    select data_req, count(servico) as qtdeServico, count(metodo) as qtdeMetodo,
           consumerid, metodo, status_metodo, servico,
           sum(tempo_req) as sum_tempo_req
    from requisicoes r
    where r.data_req > (select max(c.data_req) from consolidado c) 
    group by data_req, consumerid, metodo, status_metodo, servico;

This fixes the following errors:

• Postgres recommends CREATE TABLE AS over SELECT INTO (see here ).
• All columns should be named when creating a table.
• You need parens around the subquery.

However, the query doesn't make sense. It is creating a table called consolidado and also reading from the table. That is logically troublesome. In addition, qtMetodo and qtdeServico will generally have the same values -- they are in the GROUP BY columns meaning that they are separated by groups.

Answer 2

Try surrounding the SELECT sentence with "(....)":

SELECT
    data_req,
    count(servico) as qtdeServico,
    count(metodo) as qtdeMetodo,
    consumerid,
    metodo,
    status_metodo,
    servico,
    sum(tempo_req)
    into consolidado
    FROM requisicoes as r
    WHERE 
    r.data_req > (select max(c.data_req) from consolidado c  
    GROUP BY data_req, consumerid, metodo, status_metodo, servico);

Answer 3

Assuming consolidado already exists.. You will need to use INSERT INTO ()... SELECT syntax. The subquery should be inside parentheses as well:

INSERT INTO consolidado (data_req, qtdeServico.. rest of cols)
SELECT
    data_req,
    count(servico) as qtdeServico,
    count(metodo) as qtdeMetodo,
    consumerid,
    metodo,
    status_metodo,
    servico,
    sum(tempo_req)
FROM requisicoes as r
WHERE r.data_req > (select max(c.data_req) from consolidado c)
GROUP BY data_req, consumerid, metodo, status_metodo, servico;

Answer 4

除了关于CREATE TABLE AS和SELECT INTO的其他观点之外，我强烈建议您检出CREATE MATERIALIZED VIEW ，这听起来像是您想要的更多。