@Test
public void new_getFieldNameTest() {
int length = 100;
String name = "td";
TupleDesc td = Utility.getTupleDesc(length, name);
// Lower than index bound.
try {
td.getFieldName(length + 1);
fail("expected exception");
} catch (NoSuchElementException e) {
}
// Higher than index bound.
try {
td.getFieldName(-1);
fail("expected exception");
} catch (NoSuchElementException e) {
}
// Check each name.
for (int i = 0; i < length; i++) {
assertEquals(name + i, td.getFieldName(i));
}
}
/**
* Returns the TupleDesc with field names from the underlying HeapFile, prefixed with the
* tableAlias string from the constructor. This prefix becomes useful when joining tables
* containing a field(s) with the same name.
*
* @return the TupleDesc with field names from the underlying HeapFile, prefixed with the
* tableAlias string from the constructor.
*/
public TupleDesc getTupleDesc() {
TupleDesc tup = Database.getCatalog().getTupleDesc(id);
int length = tup.numFields();
String[] field = new String[length];
Type[] types = new Type[length];
for (int i = 0; i < length; i++) {
types[i] = tup.getFieldType(i);
field[i] = alias + "." + tup.getFieldName(i);
}
return new TupleDesc(types, field);
}
/** Test one prarmeter constructor, it should set the filed name to null. */
@Test
public void new_oneParamsConTest() {
int[] lengths = new int[] {1, 2, 1000};
for (int len : lengths) {
TupleDesc td = Utility.getTupleDesc(len);
for (int i = 0; i < len; i++) {
assertEquals("", td.getFieldName(i));
}
}
}
/** Ensures that combined's field names = td1's field names + td2's field names */
private boolean combinedStringArrays(TupleDesc td1, TupleDesc td2, TupleDesc combined) {
for (int i = 0; i < td1.numFields(); i++) {
if (!(((td1.getFieldName(i) == null) && (combined.getFieldName(i) == null))
|| td1.getFieldName(i).equals(combined.getFieldName(i)))) {
return false;
}
}
for (int i = td1.numFields(); i < td1.numFields() + td2.numFields(); i++) {
if (!(((td2.getFieldName(i - td1.numFields()) == null) && (combined.getFieldName(i) == null))
|| td2.getFieldName(i - td1.numFields()).equals(combined.getFieldName(i)))) {
return false;
}
}
return true;
}
private void createAliasedTd() {
Catalog gc = Database.getCatalog();
TupleDesc old_td = gc.getTupleDesc(tableid);
String[] newFieldAr = new String[old_td.numFields()];
Type[] typeAr = new Type[old_td.numFields()];
String field = null;
for (int i = 0; i < newFieldAr.length; i++) {
field = old_td.getFieldName(i);
if (alias == null) {
alias = "null";
} else if (field == null) {
field = "null";
}
newFieldAr[i] = alias + "." + field;
typeAr[i] = old_td.getFieldType(i);
}
td = new TupleDesc(typeAr, newFieldAr);
}