Thanks to Scott Lynch for submitting an example of how a J2EE application developer just might not trust the database to do its job.
Over to Scott...
From a big bucks retail management system (now owned by a big bucks DBMS vendor).
1. Get NextVal from the sequence.
2. Assign the value, an integer, to a string.
3. Check to see if the string they just created exists.
4. Cast the integer that has been cast to a string, to a BigDecimal.
5. Add 1 to it (because they're obviously smarter than some silly old sequence).
I just love step 3.
Sheer brilliance on that one. And it's repeated for almost every table in this particular little slice of the application.
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public long getNextId() throws java.sql.SQLException{
if (conn == null)
{
throw new java.sql.SQLException("Connection not set");
}
long nextIdLong = 0;
try
{
//Create a statement
tStmt = conn.createStatement();
//Create a query string to get all the fields from the table. The
//presentation layer will decide which field to display
String query = "SELECT some_seq.nextval FROM dual";
//The complete query is executed
rs = tStmt.executeQuery(query);
rs.next();
String nextIdString = rs.getString(1);
if (nextIdString != null) {
nextIdLong = ((new BigDecimal(nextIdString)).add(new BigDecimal(1))).longValue();
}
tStmt.close();
} catch (SQLException e)
{
throw new java.sql.SQLException(e.toString());
}
return nextIdLong;
}
