Examples with DefaultOperationObserver org.apache.cayenne.access.util.DefaultOperationObserver used on opensource projects

Example 1 with DefaultOperationObserver

use of org.apache.cayenne.access.util.DefaultOperationObserver in project cayenne by apache.

the class FlattenedArcKey method buildJoinSnapshotsForDelete.

/**
 * Returns pk snapshots for join records for the single-step flattened
 * relationship. Multiple joins between the same pair of objects are
 * theoretically possible, so the return value is a list.
 */
List buildJoinSnapshotsForDelete(DataNode node) {
    Map<String, Object> snapshot = eagerJoinSnapshot();
    DbEntity joinEntity = getJoinEntity();
    boolean fetchKey = false;
    for (DbAttribute dbAttr : joinEntity.getPrimaryKeys()) {
        String dbAttrName = dbAttr.getName();
        if (!snapshot.containsKey(dbAttrName)) {
            fetchKey = true;
            break;
        }
    }
    if (!fetchKey) {
        return Collections.singletonList(snapshot);
    }
    // ok, the key is not included in snapshot, must do the fetch...
    // TODO: this should be optimized in the future, but now
    // DeleteBatchQuery
    // expects a PK snapshot, so we must provide it.
    QuotingStrategy quoter = node.getAdapter().getQuotingStrategy();
    StringBuilder sql = new StringBuilder("SELECT ");
    Collection<DbAttribute> pk = joinEntity.getPrimaryKeys();
    final List<DbAttribute> pkList = pk instanceof List ? (List<DbAttribute>) pk : new ArrayList<>(pk);
    for (int i = 0; i < pkList.size(); i++) {
        if (i > 0) {
            sql.append(", ");
        }
        DbAttribute attribute = pkList.get(i);
        sql.append("#result('");
        sql.append(quoter.quotedName(attribute));
        // since the name of the column can potentially be quoted and
        // use reserved keywords as name, let's specify generated column
        // name parameters to ensure the query doesn't explode
        sql.append("' '").append(TypesMapping.getJavaBySqlType(attribute.getType()));
        sql.append("' '").append("pk").append(i);
        sql.append("')");
    }
    sql.append(" FROM ").append(quoter.quotedFullyQualifiedName(joinEntity)).append(" WHERE ");
    int i = snapshot.size();
    for (Object key : snapshot.keySet()) {
        sql.append(quoter.quotedIdentifier(joinEntity, String.valueOf(key))).append(" #bindEqual($").append(key).append(")");
        if (--i > 0) {
            sql.append(" AND ");
        }
    }
    SQLTemplate query = new SQLTemplate(joinEntity.getDataMap(), sql.toString(), true);
    query.setParams(snapshot);
    final List[] result = new List[1];
    node.performQueries(Collections.singleton((Query) query), new DefaultOperationObserver() {

        @Override
        public void nextRows(Query query, List<?> dataRows) {
            if (!dataRows.isEmpty()) {
                // decode results...
                List<DataRow> fixedRows = new ArrayList<>(dataRows.size());
                for (Object o : dataRows) {
                    DataRow row = (DataRow) o;
                    DataRow fixedRow = new DataRow(2);
                    for (int i = 0; i < pkList.size(); i++) {
                        DbAttribute attribute = pkList.get(i);
                        fixedRow.put(attribute.getName(), row.get("pk" + i));
                    }
                    fixedRows.add(fixedRow);
                }
                dataRows = fixedRows;
            }
            result[0] = dataRows;
        }

        @Override
        public void nextQueryException(Query query, Exception ex) {
            throw new CayenneRuntimeException("Raising from query exception.", Util.unwindException(ex));
        }

        @Override
        public void nextGlobalException(Exception ex) {
            throw new CayenneRuntimeException("Raising from underlyingQueryEngine exception.", Util.unwindException(ex));
        }
    });
    return result[0];
}