在PostgreSQL中选择具有特定列名称的列 [英] Select columns with particular column names in PostgreSQL

问题描述

我想写一个简单的查询来在PostgreSQL中选择多个列。但是，我不断收到错误 - 我尝试了几个选项，但他们不为我工作。目前我遇到以下错误：

I want to write a simple query to select a number of columns in PostgreSQL. However, I keep getting errors - I tried a few options but they did not work for me. At the moment I am getting the following error:

org.postgresql.util.PSQLException：错误：$ b $或$ $附近的语法错误bcolumn

org.postgresql.util.PSQLException: ERROR: syntax error at or near "column"

要获取具有值的列，请尝试使用followig：

To get the columns with values I try the followig:

select * from weather_data where column like '%2010%'

任何想法？

推荐答案

=http://www.postgresql.org/docs/current/interactive/sql-keywords-appendix.html =noreferrer> 保留字 。除非您双引号，否则不能将其用作标识符。像：column。

不是说你应该。只是不要使用保留字作为标识符。

Doesn't mean you should, though. Just don't use reserved words as identifiers. Ever.

至...

选择2010年的列在他们的名字：

select a list of columns with 2010 in their name:

..你可以使用这个功能从系统目录表pg_attribute动态建立SQL命令：

.. you can use this function to build the SQL command dynamically from the system catalog table pg_attribute:

CREATE OR REPLACE FUNCTION f_build_select(_tbl regclass, _pattern text)
  RETURNS text AS
$func$
    SELECT format('SELECT %s FROM %s'
                 , string_agg(quote_ident(attname), ', ')
                 , $1)
    FROM   pg_attribute 
    WHERE  attrelid = $1
    AND    attname LIKE ('%' || $2 || '%')
    AND    NOT attisdropped  -- no dropped (dead) columns
    AND    attnum > 0;       -- no system columns
$func$ LANGUAGE sql;

呼叫：

SELECT f_build_select('weather_data', '2010');

返回如下：

SELECT foo2010, bar2010_id, FROM weather_data;

您不能使此动态完全动态，因为返回类型是未知我们实际上构建了查询。

You cannot make this fully dynamic, because the return type is unknown until we actually build the query.

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