如何删除postgresql列
我的代码:如何删除postgresql列,postgresql,Postgresql,我的代码: drop table movie; CREATE TABLE movie ( imdib varchar NOT NULL, name varchar NOT NULL, year integer, rating varchar, votes varchar, runtime varchar, directors varchar, actors varchar, genres varchar ); COPY movies FROM '/home/max/Schreibtisc
drop table movie;
CREATE TABLE movie
(
imdib varchar NOT NULL,
name varchar NOT NULL,
year integer,
rating varchar,
votes varchar,
runtime varchar,
directors varchar,
actors varchar,
genres varchar
);
COPY movies FROM '/home/max/Schreibtisch/imdb_top100.txt' (DELIMITER E'\t');
COPY movies FROM '/home/max/Schreibtisch/imdb_top100t_2015-06-18.csv' (DELIMITER E'\t', FORMAT CSV);
SELECT actors, unnest(string_to_array(actors, '|')) AS Schauspieler from kinofilme;
SELECT directors, unnest(string_to_array(directors, '|')) AS Regisseure from movies;
SELECT genres, unnest(string_to_array(genres, '|')) AS Genrees from movies;
对最后3条语句的解释:体裁、演员和导演用“|”分隔(例如:体裁:动作|戏剧|惊悚片)
但我只想从体裁中获得一种体裁(例如从动作片、戏剧、惊悚片中获得唯一的动作片),这就是我使用unnest(字符串数组)的原因。问题是输出。当我使用选择流派时,unnest(string_to_array(流派,“|”)作为电影的流派代码>输出为:
类型(字符变化)\ uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
犯罪、戏剧、犯罪
犯罪剧
动作、戏剧、动作
动作剧
我想删除第一列“流派”,因为select语句不需要它。我只需要第二栏“Genrees”,其中显示了每种流派。如何删除第一个左科伦命名为“流派”或如何使其“消失”?提前感谢您。请使用此功能
SELECT regexp_replace(genres,'\|.*','') AS Genrees from movies;
这会回来的
Crime
Action
对于您的示例您是否正在查找更改表格放置列
?我尝试了此操作,但无法创建表格,因为缺少“流派”。@Blnpwr我的答案有什么问题?