SQL IS NOT NULL 的 Rails 范围并且不为空/空白？
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Rails scope for IS NOT NULL and is not empty/blank?
提问by Shpigford
I have the following scope:
我有以下范围：
scope :comments, :conditions => ['text_value IS NOT NULL']
But I also want the conditions to say "OR text_value IS NOT EMPTY" (or something to that effect).
但我也希望条件说“OR text_value IS NOT EMPTY”（或类似的东西）。
I don't want to select any rows where text_valueis empty/blank.
我不想选择任何text_value空/空白的行。
回答by Patrick Oscity
In Rails 4 you can do
在 Rails 4 中你可以做
where.not(text_value: '')
回答by Jordan Running
As Erwin points out, a simple text_value <> ''comparison will work in this case.
正如 Erwin 所指出的，text_value <> ''在这种情况下可以进行简单的比较。
scope :comments, where("text_value <> ''")
(Rails 3 prefers this query syntax for scope—as well as find, all, etc.—rather than an options hash e.g. :conditions => .... The latter is deprecated in Rails 3.1.)
（导轨3喜欢此查询语法scope-as以及find，all等等-而不是一个选项散列例如:conditions => ...，后者是在滑轨3.1弃用）。
In Rails 4, the second argument should be a lambda instead:
在 Rails 4 中，第二个参数应该是一个 lambda：
scope :comments, ->{ where("text_value <> ''") }
回答by miclle
rails 4
导轨 4
scope :comments, -> { where.not(:text_value => nil) }
回答by Erwin Brandstetter
Use text_value <> ''to efficiently cover bothcases.
使用text_value <> ''以有效地覆盖这两种情况。
Will only be TRUEfor a text_valuethat is neither NULLnor empty.
只会TRUE用于text_value既不是也不NULL是empty。
回答by Marek P?íhoda
scope :comments, where("text_value <> ''")
回答by yivo
Personally I am doing like this:
我个人是这样做的：
1) Add to initializers
1) 添加到初始值设定项
class Arel::Attributes::Attribute
# Encode column name like: `posts`.`author_id`
def to_sql
"`#{relation.table_name}`.`#{name}`"
end
def is_not_empty
"#{to_sql} <> ''"
end
end
2) Add to your model
2）添加到您的模型
scope :comments, -> { where(arel_table[:text_value].is_not_empty) }
Good luck!
祝你好运！
