75 Advanced Java Tutorial |JDBC | Batch Processing | Java Database Connectivity | adv java

Advanced Java Java Tutorial: adv java: #Batch Processing: Java Database Connectivity:
Instead of sending multiple queries as individual / seperate/one by one query to database software by using network for multile times, its recommended to combine them (all queries) into single batch/unit and send that batch to DataBase once for execution this is called as batch processing.

- This reduce network round trips between java application & DataBase s/w.

Example. if there are 10 queries to send the queries to database software instead of sending them individually or seperately for 10 times by having 10 n/w roundtrips with browser window or java application, its recommended to combine them into single unit/batch and send that batch to database only for 1 time.

- We can not add select sql queries to the batch of batch processing.

sample code for batch processing.
---------------------------------

Statement st=con.createStatement();

// add queries to batch
st.addBatch("insert into student values (674,"ajay","mumbai");
st.addBatch("update student set sadd="hyd" where sno=200");
st.addBatch("delete from student where sno=300");
.
.
.

//Execute the batch
int res[]=st.executeBatch(); //{2,3,5};

//process the result
int sum=0;

for(i=0;i less than res.length;++i)
{
sum=sum+res[i];
}
System.out.println("No of record that are affected "+sum);

--Batch processing does not execute queries by default applying do everything or nothing principle for this we need to write additional logic (Ex. A transaction management withdraw and deposite)

-In Batch processing java application send queries to database as a batch, similarly query result is come back to application as a batch.


-All non-select query execution gives the numeric result (insert, update, delete). A select query execution gives ResultSet object.executeBatch(-) method return type is int[](Array) and it cannot stored ResultSet object, so we cannot add select query to Batch.

-The process of combining related/simliar/common operation into single unit/batch and executing them by applying do everything and nothing principle is called as transaction management.

-Batch processing does not perform transaction management on its own.
But we can bring that effect/logic on batch processing by disabling autocommit mode and by writing additional logic using con.commit(), con.rollback().

Ex. Java JDBC application on batch processing a with transaction management support :
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