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POServiceStack: Detect if IDbConnection is "busy" - is a DataReader is open (trying to implement a "connection pool")
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  1. POServiceStack: Detect if IDbConnection is "busy" - is a DataReader is open (trying to implement a "connection pool")
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    copied!<p>I am testing out ServiceStacks OrmLite. I have previosly used MySql without OrmLite and now I am faced with the problem easiest described in this error message:</p> <blockquote> <p>There is already an open DataReader associated with this Connection which must be closed first.</p> </blockquote> <p>Since I have a multi-threaded application, certain threads will be polling the database, while other will insert, update or select "on demand", when needed. This results in the above mentioned exception.</p> <p>What I need to do is to be able to detect if a connection (IDbHandler) is "busy"; has an open DataReader or something else that. If it is busy, take the next connection (from the "connection pool" i want to implement). The problem is, there is no method or property I can use in the IDbHandler object to determine if it is busy or not.</p> <p>I have solved this in the "normal" mysql case by simply having a method where I send in the MySqlCommand or just the query string, like:</p> <pre><code>dbConnections.ExecuteQuery("SELECT * FROM test"); dbConnections.ExecuteQuery(cmd); // cmd == MySqlCommand </code></pre> <p>and the ExecuteQuery will handle of finding an open connection and just passing on the cmd/query there. </p> <p>But, since I am using OrmLite it has a lot of extension methods to IDbConnection and I do not want to create "proxy methods" for each one. In the simple mysql case above, there is really only one method needed, that takes in a MySqlCommand, but not so with the many methods in OrmLite.</p> <p>The first question:</p> <ul> <li>How can I detect if a connection is busy? I want to avoid a try-catch situation to detect it.</li> </ul> <p>Second question:</p> <ul> <li>Is there some way to pass the entire "method" call, something like:</li> </ul> <p>Example:</p> <pre><code>dbConnections.Run(iDbHandler.Select&lt;MyObject&gt;(q =&gt; q.Id &gt; 10)); // or dbConnections.Run(iDbHandler.Where&lt;MyObject&gt;(q =&gt; q.Id &gt; 10)); // or dbConnections.Run(iDbHandler.SomeOtherWeirdMetod&lt;MyObject&gt;(q =&gt; bla bla bla)); </code></pre>
 

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