CODEWITHSUNDEEP
spring-batch
Vicky
Vicky

Reputation: 17375

deleting records through spring batch

I have a file with records.

I have to develop a spring batch program which will read the file and DELETE the same records from the database table.

Is it possible to run delete query through ItemWriter ???

Upvotes: 1

Views: 23275

Answers (2)

Michael Pralow
Michael Pralow

Reputation: 6630

Serkans answer is right, but there are some more possibilities for working with batch sql

  1. you could use spring-jdbc-batch-template instead of the normal jdbc-template
  2. you could directly use the spring-batch-jdbc-item-writer see example code

code example with spring batch xml config and java code

<bean id="itemWriter" class="org.springframework.batch.item.database.JdbcBatchItemWriter">
    <property name="dataSource" ref="dataSource" />
    <property name="sql">
        <!-- Why CDATA? 

             because < etc. is not allowed for xml values
             when you use &lt; xml parser will work, but
             now the sql won't because of the & spring assumes
             a placeholder, see
             - AbstractSqlPagingQueryProvider.init(...)
             - JdbcParameterUtils.countParameterPlaceholders(...)

             -->
        <value>
            <![CDATA[
                DELETE FROM TEST
                WHERE id = ? 
                and sub.id = ?
                and ... 
            ]]>
        </value>
    </property>
    <property name="itemPreparedStatementSetter">
        <bean class="...FieldSetItemPreparedStatementSetter" />
    </property>        
</bean>

/**
 * Implementation for {@link ItemPreparedStatementSetter}, 
 * sets the values from {@link FieldSet}.
 * 
 */
public class FieldSetItemPreparedStatementSetter implements ItemPreparedStatementSetter<FieldSet> {

    /** {@inheritDoc} */
    @Override
    public void setValues(FieldSet item, PreparedStatement ps) throws SQLException {
        for (int i = 0; i < item.getValues().length; i++) {
            // PreparedStatements start with 1
            ps.setObject(i + 1, item.getValues()[i]);
        }
    }
}

Upvotes: 3

Serkan Arıkuşu
Serkan Arıkuşu

Reputation: 5619

There is no difference between update or delete operations, only the sql changes; so simple answer to your question will be yes. The following code fragment may help for basic needs assuming that you are deleting from the Book table.

public class BookJdbcItemWriter implements ItemWriter<Book> {

        private static final String DELETE_BOOK = "delete from Book where id = ?";

        private JdbcTemplate jdbcTemplate;

        public BookJdbcItemWriter(DataSource dataSource) {
                this.jdbcTemplate = new JdbcTemplate(dataSource);
        }

        public void write(List<? extends Book> items) throws Exception {
                for(Book item : items) {
                        int updated = jdbcTemplate.update(DELETE_BOOK,item.getId());                                                           
                }
        }
}

Upvotes: 1

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