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javanumberscommitrecordsrowset

Commit certain number of records to DB with java


I have table in DB,e.g. TableOne.
By some rules i should commit N records from this table to other tables.
Is it possible to do with jdbc or ResultSet or CachedRowSet?

Preliminary flow, as i see:
1. loop through ResultSet of TableOne
2. increment counter if certain condition is met
3. if condition is not met, it's time to commit to other DB tables N records=counter
4. commit these N records

So,the question is in step 4.
How it may be implemented?

Thank you.


Solution

  • The purpose of the counter is unclear, so I am going to assume that you are just using it to illustrate the fact that you are only committing records that match the condition.

    Try constructing an insert statement that does all the work:

    INSERT INTO table2 (a, b, c)
        SELECT a, b, c FROM table1
    WHERE myConditionIsMet
    

    The other option is to loop over the record set and insert a record every time the condition is met. You should wrap the loop in a transaction so nothing gets committed until after the loop has completed. My JDBC is a little rusty so here is a psuedocode example:

    connection.startTransaction()
    for row in records
        if row condition
            connection.execute('INSERT ROW STATEMENENT')
    connection.commitTransaction()
    

    The first approach is preferable, but there maybe some situations where the condition can't be determined within an SQL expression.