public String rewriteQuery(Query query) {
query = beforeRewrite(query);
final StringBuilder sb = new StringBuilder();
sb.append(rewriteSelectClause(query, query.getSelectClause()));
sb.append(rewriteFromClause(query, query.getFromClause()));
sb.append(rewriteWhereClause(query, query.getWhereClause()));
sb.append(rewriteGroupByClause(query, query.getGroupByClause()));
sb.append(rewriteHavingClause(query, query.getHavingClause()));
sb.append(rewriteOrderByClause(query, query.getOrderByClause()));
return sb.toString();
}
@Override
public DataSet executeQuery(Query query) {
final List<FromItem> fromItems = query.getFromClause().getItems();
if (fromItems.size() != 1) {
// not a simple SELECT ... FROM [table] ... query, we need to use
// query post processing.
return super.executeQuery(query);
}
final Table table = fromItems.get(0).getTable();
if (table == null) {
return super.executeQuery(query);
}
if (!query.getGroupByClause().isEmpty()) {
return super.executeQuery(query);
}
if (!query.getHavingClause().isEmpty()) {
return super.executeQuery(query);
}
final List<SelectItem> selectItems = query.getSelectClause().getItems();
final StringBuilder sb = new StringBuilder();
try {
sb.append("SELECT ");
int i = 0;
final Column[] columns = new Column[selectItems.size()];
for (SelectItem selectItem : selectItems) {
validateSoqlSupportedSelectItem(selectItem);
columns[i] = selectItem.getColumn();
if (i != 0) {
sb.append(", ");
}
sb.append(columns[i].getName());
i++;
}
sb.append(" FROM ");
sb.append(table.getName());
boolean firstWhere = true;
for (FilterItem filterItem : query.getWhereClause().getItems()) {
if (firstWhere) {
sb.append(" WHERE ");
firstWhere = false;
} else {
sb.append(" AND ");
}
rewriteFilterItem(sb, filterItem);
}
i = 0;
final List<OrderByItem> items = query.getOrderByClause().getItems();
for (OrderByItem orderByItem : items) {
if (i == 0) {
sb.append(" ORDER BY ");
} else {
sb.append(", ");
}
final SelectItem selectItem = orderByItem.getSelectItem();
validateSoqlSupportedSelectItem(selectItem);
final Column column = selectItem.getColumn();
sb.append(column.getName());
sb.append(' ');
sb.append(orderByItem.getDirection());
i++;
}
final Integer firstRow = query.getFirstRow();
final Integer maxRows = query.getMaxRows();
if (maxRows != null && maxRows > 0) {
if (firstRow != null) {
// add first row / offset to avoid missing some records.
sb.append(" LIMIT " + (maxRows + firstRow - 1));
} else {
sb.append(" LIMIT " + maxRows);
}
}
final QueryResult result = executeSoqlQuery(sb.toString());
DataSet dataSet = new SalesforceDataSet(columns, result, _connection);
if (firstRow != null) {
// OFFSET is still only a developer preview feature of SFDC. See
// http://www.salesforce.com/us/developer/docs/api/Content/sforce_api_calls_soql_select_offset.htm
dataSet = new FirstRowDataSet(dataSet, firstRow.intValue());
}
return dataSet;
} catch (UnsupportedOperationException e) {
logger.debug(
"Failed to rewrite query to SOQL, falling back to regular query post-processing", e);
return super.executeQuery(query);
}
}