private String getSQLGroupConcat() {
StatementBuilder buff = new StatementBuilder("GROUP_CONCAT(");
if (distinct) {
buff.append("DISTINCT ");
}
buff.append(on.getSQL());
if (groupConcatOrderList != null) {
buff.append(" ORDER BY ");
for (SelectOrderBy o : groupConcatOrderList) {
buff.appendExceptFirst(", ");
buff.append(o.expression.getSQL());
if (o.descending) {
buff.append(" DESC");
}
}
}
if (groupConcatSeparator != null) {
buff.append(" SEPARATOR ").append(groupConcatSeparator.getSQL());
}
return buff.append(')').toString();
}
@Override
public Value getValue(Session session) {
if (select.isQuickAggregateQuery()) {
switch (type) {
case COUNT:
case COUNT_ALL:
Table table = select.getTopTableFilter().getTable();
return ValueLong.get(table.getRowCount(session));
case MIN:
case MAX:
boolean first = type == MIN;
Index index = getColumnIndex();
int sortType = index.getIndexColumns()[0].sortType;
if ((sortType & SortOrder.DESCENDING) != 0) {
first = !first;
}
Cursor cursor = index.findFirstOrLast(session, first);
SearchRow row = cursor.getSearchRow();
Value v;
if (row == null) {
v = ValueNull.INSTANCE;
} else {
v = row.getValue(index.getColumns()[0].getColumnId());
}
return v;
default:
DbException.throwInternalError("type=" + type);
}
}
HashMap<Expression, Object> group = select.getCurrentGroup();
if (group == null) {
throw DbException.get(ErrorCode.INVALID_USE_OF_AGGREGATE_FUNCTION_1, getSQL());
}
AggregateData data = (AggregateData) group.get(this);
if (data == null) {
data = AggregateData.create(type);
}
Value v = data.getValue(session.getDatabase(), dataType, distinct);
if (type == GROUP_CONCAT) {
ArrayList<Value> list = ((AggregateDataGroupConcat) data).getList();
if (list == null || list.size() == 0) {
return ValueNull.INSTANCE;
}
if (groupConcatOrderList != null) {
final SortOrder sortOrder = groupConcatSort;
Collections.sort(
list,
new Comparator<Value>() {
@Override
public int compare(Value v1, Value v2) {
Value[] a1 = ((ValueArray) v1).getList();
Value[] a2 = ((ValueArray) v2).getList();
return sortOrder.compare(a1, a2);
}
});
}
StatementBuilder buff = new StatementBuilder();
String sep =
groupConcatSeparator == null ? "," : groupConcatSeparator.getValue(session).getString();
for (Value val : list) {
String s;
if (val.getType() == Value.ARRAY) {
s = ((ValueArray) val).getList()[0].getString();
} else {
s = val.getString();
}
if (s == null) {
continue;
}
if (sep != null) {
buff.appendExceptFirst(sep);
}
buff.append(s);
}
v = ValueString.get(buff.toString());
}
return v;
}