如果你不介意额外的空格和换行，你可以使用

conn.exec %w{select attr1, attr2, attr3, attr4, attr5, attr6, attr7
  from table1, table2, table3, etc, etc, etc, etc, etc,
  where etc etc etc etc etc etc etc etc etc etc etc etc etc} * ' '

(使用%W表示插值字符串)

是的，如果你不介意额外的换行被插入:

 conn.exec 'select attr1, attr2, attr3, attr4, attr5, attr6, attr7
            from table1, table2, table3, etc, etc, etc, etc, etc,
            where etc etc etc etc etc etc etc etc etc etc etc etc etc'

你也可以使用heredoc:

conn.exec <<-eos
   select attr1, attr2, attr3, attr4, attr5, attr6, attr7
   from table1, table2, table3, etc, etc, etc, etc, etc,
   where etc etc etc etc etc etc etc etc etc etc etc etc etc
eos

在ruby 2.0中，你现在可以只使用%

例如:

    SQL = %{
      SELECT user, name
      FROM users
      WHERE users.id = #{var}
      LIMIT #{var2}
    }

最近，随着Ruby 2.3的新特性，新的弯弯曲曲的HEREDOC将允许您以一种非常好的方式编写多行字符串，并且只需要进行最小的更改，因此，将它与.squish(如果您正在使用rails)结合使用将使您以一种非常好的方式编写多行字符串! 在只使用ruby的情况下，您可以执行<<~SQL.split。Join(" ")，几乎相同

[1] pry(main)> <<~SQL.squish
[1] pry(main)*   select attr1, attr2, attr3, attr4, attr5, attr6, attr7
[1] pry(main)*   from table1, table2, table3, etc, etc, etc, etc, etc,
[1] pry(main)*   where etc etc etc etc etc etc etc etc etc etc etc etc etc
[1] pry(main)* SQL
=> "select attr1, attr2, attr3, attr4, attr5, attr6, attr7 from table1, table2, table3, etc, etc, etc, etc, etc, where etc etc etc etc etc etc etc etc etc etc etc etc etc"

裁判:https://infinum.co/the-capsized-eight/multiline-strings-ruby-2-3-0-the-squiggly-heredoc

你也可以使用双引号

x = """
this is 
a multiline
string
"""

2.3.3 :012 > x
 => "\nthis is\na multiline\nstring\n"

如果需要删除换行符“\n”，请在每行末尾使用反斜杠“\”

conn.exec = <<eos
  select attr1, attr2, attr3, attr4, attr5, attr6, attr7
  from table1, table2, table3, etc, etc, etc, etc, etc,
  where etc etc etc etc etc etc etc etc etc etc etc etc etc
eos