Question

I have some records to import. It’s ok the first time when they are being inserted. If I try to import the same data again I receive a org.postgresql.util.PSQLException: ERROR: duplicate key value violates unique constraint. How can I update the records in the database if the data is the same/or changed and insert if it’s new data using JDBC?

public void store(Object entity) throws Exception {
    try {
        if (this.updateEntity((XEntity) entity) == 0) {
            this.insertEntity((XEntity) entity);
        }

        ...

    } catch (SQLException sqlEx) {
        ...
    }
}

private int updateEntity(XEntity entity) throws SQLException {
    PreparedStatement prepStmt = this.getUpdatePreparedStmt();
    ...
    return prepStmt.executeUpdate();
}

private void insertEntity(XEntity entity) throws SQLException {
    ...
    this.getInsertPreparedStmt().executeUpdate();
}

The problem is fixed now. I’ve provided an answer below.

Answer 1

This test logic works.

if (this.updateEntity((XEntity) entity) == 0) {
    this.insertEntity((XEntity) entity);
}

The problem was in the method that updated the record. The WHERE clause in the update prepared statement was using different data(data containing spaces) so updateEntity would always return 0. That was the reason why only inserts were made, instead of updates. Thank you very much for your help.