What is a validationQuery with respect to databases and JNDI?

java jdbc database-connection sybase jndi
IAmYourFaja picture IAmYourFaja · Mar 13, 2013 · Viewed 16.6k times · Source

I seem to be having the same exact problem as the poster of this original SO question.

The problem is, he answered his own question with the following comment:

I solved my problem, I added a validationQuery to my JNDI datasource.

Unfortunately, that doesn't mean anything to me, and doesn't help me solve my problem. So I ask: what is a "validationQuery" with respect to my database (Sybase) and the JNDI entry used to hold the server lookup info?

Thanks in advance.

Answer

rgettman picture rgettman · Mar 13, 2013

The validation query is a query run by the data source to validate that a Connection is still open before returning it. Here's Tomcat's definition of a validation query; scroll down to the middle of section "4. Configure Tomcat's Resource Factory", looking for the "validationQuery" attribute.

EDIT

According to this answer, if the validation query fails, no error is thrown; the bad/closed connection is dropped and another connection is created to replace it.

Related questions

How do I find out my MySQL URL, host, port and username?

I need to find my MySQL username. When I open the MySQL command line client, it only asks me for my password. I don't remember my username. And for connectivity with JDBC, I need the URL, host and port number. …

Read More
Connection timeout for DriverManager getConnection

I am trying to connect to DB using the standard JDBC way connection = DriverManager.getConnection(url, username, password); Is there a maximum value of timeout on the connection, how long does a connection live, can I increase the value. I …

Read More
Connecting a Microsoft Access Database to Java using JDBC and compiling

for a school database project we are making a database program (user GUI and the database). Using Microsoft Access 2010 I created the database and populated it with some sample data, and saved it in .mdb format and placed it in …

Read More