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POFetch all entries exept those with empty column in Rails
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  1. POFetch all entries exept those with empty column in Rails
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    copied!<p>How do I fetch all 'link' entries exept those with an 'url' column that is blank? My controller looks like this:</p> <pre><code> def show @user = User.find_by_username(params[:username]) @links = @user.links.all respond_to do |format| format.html # show.html.erb format.xml { render :xml =&gt; @links } end end </code></pre> <p>Thanks in advance!</p> <p><strong>Edit #1</strong></p> <p>If I do:</p> <pre><code>@links = @user.all(:conditions =&gt; 'url != NULL') </code></pre> <p>I get a error:</p> <pre><code>NoMethodError in UsersController#show undefined method `all' for #&lt;User:0x2254f98&gt; </code></pre> <p>And if I do:</p> <pre><code>@links = @user.links.all(:conditions =&gt; 'url != NULL') </code></pre> <p>I still get all the links, even those with empty url fields...</p> <p><strong>Edit #2</strong></p> <p>If I do</p> <pre><code>@links = User.all(:conditions =&gt; 'url != NULL') </code></pre> <p>I get </p> <pre><code>ActiveRecord::StatementInvalid in UsersController#show SQLite3::SQLException: no such column: url: SELECT * FROM "users" WHERE (url != NULL) </code></pre> <p>And if I do</p> <pre><code>@links = Link.all(:conditions =&gt; 'url != NULL') </code></pre> <p>I still get all the links, even those with empty url fields...</p> <p>I'm wondering if it's a difference between NULL and the field beeing empty?</p> <p><strong>Edit #3</strong></p> <p>Now my code looks like this:</p> <pre><code> def show @user = User.find_by_username(params[:username]) @links = @user.links.all(:conditions =&gt; "url &lt;&gt; ''") respond_to do |format| format.html # show.html.erb format.xml { render :xml =&gt; @links } end end </code></pre> <p><strong>Solution</strong></p> <pre><code>#controller @links = @user.links.not_null_url #model named_scope :not_null_url, :conditions =&gt; "url &lt;&gt; ''" </code></pre> <p>This works! Just be sure access the links with:</p> <pre><code>#view &lt;% @links.each do |link| %&gt; </code></pre> <p>And not:</p> <pre><code>#view &lt;% @user.links.each do |link| %&gt; </code></pre>
 

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