protected final Field<?> getField(Table<?> table, String name) {
Field<?> result = table.field(name);
if (result == null) {
result = table.field(name.toUpperCase());
}
if (result == null) {
result = table.field(name.toLowerCase());
}
return result;
}
/** Extracted method for type-safety */
private <Z> Condition condition(Table<?> pivot, Field<Z> field) {
return field.equal(pivot.field(field));
}
private Table<Record> select(Configuration configuration) {
List<Field<?>> groupingFields = new ArrayList<Field<?>>();
List<Field<?>> aliasedGroupingFields = new ArrayList<Field<?>>();
List<Field<?>> aggregatedFields = new ArrayList<Field<?>>();
Table<?> pivot = table.as("pivot_outer");
// Clearly, the API should be improved to make this more object-
// oriented...
// This loop finds all fields that are used in aggregate
// functions. They're excluded from the GROUP BY clause
for (Field<?> field : aggregateFunctions) {
if (field instanceof Function) {
for (QueryPart argument : ((Function<?>) field).getArguments()) {
if (argument instanceof Field) {
aggregatedFields.add((Field<?>) argument);
}
}
}
}
// This loop finds all fields qualify for GROUP BY clauses
for (Field<?> field : table.fields()) {
if (!aggregatedFields.contains(field)) {
if (!on.equals(field)) {
aliasedGroupingFields.add(pivot.field(field));
groupingFields.add(field);
}
}
}
// The product {aggregateFunctions} x {in}
List<Field<?>> aggregationSelects = new ArrayList<Field<?>>();
for (Field<?> inField : in) {
for (Field<?> aggregateFunction : aggregateFunctions) {
Condition join = trueCondition();
for (Field<?> field : groupingFields) {
join = join.and(condition(pivot, field));
}
@SuppressWarnings("unchecked")
Select<?> aggregateSelect =
using(configuration)
.select(aggregateFunction)
.from(table)
.where(on.equal((Field<T>) inField))
.and(join);
aggregationSelects.add(
aggregateSelect.asField(inField.getName() + "_" + aggregateFunction.getName()));
}
}
// This is the complete select
Table<Record> select =
using(configuration)
.select(aliasedGroupingFields)
.select(aggregationSelects)
.from(pivot)
.where(pivot.field(on).in(in.toArray(new Field[0])))
.groupBy(aliasedGroupingFields)
.asTable();
return select;
}
