Querying a Database from a session bean using JDBC
Joined: Jan 27, 2005
I am developing an application that requires the querying of an external database i.e. user requests a number of fields which are stored in the applications database and these are then used to query a second database for the actual values. If anyone can understand what i am talking about, can you direct me as to whats the best approach to doing this. I am using MySQL DB and have been advised to use JDBC in a session bean?
Fiona, Basically you have two queries. So the high level approach is: 1) Query external database (database 1) 2) Loop through result set and store fields in variables (or List if multiple rows.) 3) Build sql string for second query. I recommend using prepared statements so you can easily substitute in the values. 4) Run second query (database 2) 5) Loop through result set and process actual values
The logic behind separating the queries is so you can close the first connection sooner. Take a look at Sun's JDBC tutorial to get started with JDBC.
For the future, I recommend posting this type of question in the JDBC forum since it is more about JDBC than session beans.
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