@Override
public void visit(Select obj) {
visitNodes(obj.getFrom());
visitNodes(obj.getDerivedColumns());
visitNode(obj.getWhere());
visitNode(obj.getGroupBy());
visitNode(obj.getHaving());
visitNode(obj.getOrderBy());
visitNode(obj.getLimit());
if (this.doScanEvaluation) {
HashMap<String, String> options =
buildTableMetadata(
this.scanTable.getName(), this.scanTable.getColumns(), this.ef.getEncoding());
options.put(EvaluatorIterator.QUERYSTRING, SQLStringVisitor.getSQLString(obj.getWhere()));
IteratorSetting it = new IteratorSetting(1, EvaluatorIterator.class, options);
this.scanIterators.add(it);
}
if (this.selectColumns.size() < this.scanTable.getColumns().size()) {
HashMap<String, String> options =
buildTableMetadata(this.scanTable.getName(), this.selectColumns, this.ef.getEncoding());
IteratorSetting it =
new IteratorSetting(iteratorPriority++, LimitProjectionIterator.class, options);
this.scanIterators.add(it);
}
}
@Override
public void execute() throws TranslatorException {
LogManager.logTrace(
LogConstants.CTX_CONNECTOR,
"ObjectExecution command:",
query.toString(),
"using connection:",
connection.getClass().getName()); // $NON-NLS-1$ //$NON-NLS-2$
String nameInSource =
getNameInSource(((NamedTable) query.getFrom().get(0)).getMetadataObject());
List<Object> results = factory.search(query, nameInSource, connection, executionContext);
if (results != null && results.size() > 0) {
LogManager.logDetail(
LogConstants.CTX_CONNECTOR,
"ObjectExecution number of returned objects is :",
results.size()); // $NON-NLS-1$
} else {
LogManager.logDetail(
LogConstants.CTX_CONNECTOR,
"ObjectExecution number of objects returned is : 0"); //$NON-NLS-1$
results = Collections.emptyList();
}
this.resultsIt = results.iterator();
}
@Override
public List<?> translateCommand(Command command, ExecutionContext context) {
if (command instanceof Insert) {
try {
handleInsertSequences((Insert) command);
} catch (TranslatorException e) {
throw new RuntimeException(e);
}
}
if (!(command instanceof QueryExpression)) {
return null;
}
QueryExpression queryCommand = (QueryExpression) command;
if (queryCommand.getLimit() == null) {
return null;
}
Limit limit = queryCommand.getLimit();
queryCommand.setLimit(null);
if (command instanceof Select) {
Select select = (Select) command;
TableReference tr = select.getFrom().get(0);
if (tr instanceof NamedTable && isDual((NamedTable) tr)) {
if (limit.getRowOffset() > 0 || limit.getRowLimit() == 0) {
// no data
select.setWhere(
new Comparison(
new Literal(1, TypeFacility.RUNTIME_TYPES.INTEGER),
new Literal(0, TypeFacility.RUNTIME_TYPES.INTEGER),
Operator.EQ));
return null;
}
return null; // dual does not allow a limit
}
}
List<Object> parts = new ArrayList<Object>();
parts.add("SELECT "); // $NON-NLS-1$
/*
* if all of the columns are aliased, assume that names matter - it actually only seems to matter for
* the first query of a set op when there is a order by. Rather than adding logic to traverse up,
* we just use the projected names
*/
boolean allAliased = true;
for (DerivedColumn selectSymbol : queryCommand.getProjectedQuery().getDerivedColumns()) {
if (selectSymbol.getAlias() == null) {
allAliased = false;
break;
}
}
if (allAliased) {
String[] columnNames = queryCommand.getColumnNames();
for (int i = 0; i < columnNames.length; i++) {
if (i > 0) {
parts.add(", "); // $NON-NLS-1$
}
parts.add(columnNames[i]);
}
} else {
parts.add("*"); // $NON-NLS-1$
}
if (limit.getRowOffset() > 0) {
parts.add(" FROM (SELECT VIEW_FOR_LIMIT.*, ROWNUM ROWNUM_ FROM ("); // $NON-NLS-1$
} else {
parts.add(" FROM ("); // $NON-NLS-1$
}
parts.add(queryCommand);
if (limit.getRowOffset() > 0) {
parts.add(") VIEW_FOR_LIMIT WHERE ROWNUM <= "); // $NON-NLS-1$
parts.add(limit.getRowLimit() + limit.getRowOffset());
parts.add(") WHERE ROWNUM_ > "); // $NON-NLS-1$
parts.add(limit.getRowOffset());
} else {
parts.add(") WHERE ROWNUM <= "); // $NON-NLS-1$
parts.add(limit.getRowLimit());
}
return parts;
}