Efficient way to do batch INSERTS with JDBC

Question

In my app I need to do a lot of INSERTS. Its a Java app and I am using plain JDBC to execute the queries. The DB being Oracle. I have enabled batching though, so it saves me

Answer 1

The Statement gives you the following option:

Statement stmt = con.createStatement();

stmt.addBatch("INSERT INTO employees VALUES (1000, 'Joe Jones')");
stmt.addBatch("INSERT INTO departments VALUES (260, 'Shoe')");
stmt.addBatch("INSERT INTO emp_dept VALUES (1000, 260)");

// submit a batch of update commands for execution
int[] updateCounts = stmt.executeBatch();

Answer 2

In my code I have no direct access to the 'preparedStatement' so I cannot use batch, I just pass it the query and a list of parameters. The trick however is to create a variable length insert statement, and a LinkedList of parameters. The effect is the same as the top example, with variable parameter input length.See below (error checking omitted). Assuming 'myTable' has 3 updatable fields: f1, f2 and f3

String []args={"A","B","C", "X","Y","Z" }; // etc, input list of triplets
final String QUERY="INSERT INTO [myTable] (f1,f2,f3) values ";
LinkedList params=new LinkedList();
String comma="";
StringBuilder q=QUERY;
for(int nl=0; nl< args.length; nl+=3 ) { // args is a list of triplets values
    params.add(args[nl]);
    params.add(args[nl+1]);
    params.add(args[nl+2]);
    q.append(comma+"(?,?,?)");
    comma=",";
}      
int nr=insertIntoDB(q, params);

in my DBInterface class I have:

int insertIntoDB(String query, LinkedList <String>params) {
    preparedUPDStmt = connectionSQL.prepareStatement(query);
    int n=1;
    for(String x:params) {
        preparedUPDStmt.setString(n++, x);
    }
    int updates=preparedUPDStmt.executeUpdate();
    return updates;
}

Answer 3

Batch insert using statement

int a= 100;
            try {
                        for (int i = 0; i < 10; i++) {
                            String insert = "insert into usermaster"
                                    + "("
                                    + "userid"
                                    + ")"
                                    + "values("
                                    + "'" + a + "'"
                                    + ");";
                            statement.addBatch(insert);
                            System.out.println(insert);
                            a++;
                        }
                      dbConnection.commit();
                    } catch (SQLException e) {
                        System.out.println(" Insert Failed");
                        System.out.println(e.getMessage());
                    } finally {
            
                        if (statement != null) {
                            statement.close();
                        }
                        if (dbConnection != null) {
                            dbConnection.close();
                        }
                    }
        

Answer 4

You can use this rewriteBatchedStatements parameter to make the batch insert even faster.

you can read here about the param: MySQL and JDBC with rewriteBatchedStatements=true