/**
* Check if a tuple attribute reference is valid. Disambiguate if needed. Also set the
* RelationSchema for the TupleAttribute. *
*/
boolean analyzeTupleAttribute(TupleAttribute ta) {
if (ta.tableName == null) {
BaseRelationSchema found_in = null;
for (BaseRelationSchema rs : query_relations) {
// System.out.println("searching for " + ta.attributeName + " in " + rs);
if (rs.hasAttribute(ta.attributeName)) {
if (found_in == null) {
found_in = rs;
} else {
System.out.println("=========> Attribute " + ta.attributeName + " ambiguous");
return false;
}
}
}
if (found_in != null) {
ta.tableName = found_in.getName();
ta.setRelationSchema(found_in);
return true;
} else {
System.out.println(
"=========> Attribute "
+ ta.attributeName
+ " not found in any of the tables in the FROM clause");
return false;
}
} else {
if (!checkRelationContainedInFromClause(ta.tableName)) {
System.out.println("=========> Relation " + ta.tableName + " not in the From Clause");
return false;
}
ta.setRelationSchema(Globals.getRelationSchema(ta.tableName));
if (!ta.rs.hasAttribute(ta.attributeName)) {
System.out.println(
"=========> Attribute "
+ ta.attributeName
+ " not present in the relation "
+ ta.tableName);
return false;
}
return true;
}
}
