updating

DBEngine.cpp

@@ -85,12 +85,33 @@ void DBEngine::rename(Relation& r, vector<string> oldnames, vector<string> newna
 }
 
 Relation DBEngine::setUnion(Relation r1, Relation r2){
-	if (r1.getAttributes() != r2.getAttributes()){
+	if (r1.getAttributeNames() != r2.getAttributeNames()){
 		cout << "Failure to union: the relations are not union-compatible";
 		return;
 	}
 
 	else {
+		vector<Attribute> r1_atts = r1.getAttributes();
+		vector<Attribute> r2_atts = r2.getAttributes();
+		vector<Attribute> new_atts = r1_atts;
+		
+		for (int i = 0; i < r2_atts.size(); ++i) {
+			for (int j = 0; j < r2_atts[i].getSize(); ++j){
+				new_atts[i].addCell(r2_atts[i][j]);
+			}
+		}
 
+		for (int i = 0; i < new_atts.size(); ++i) {
+			for (int j = 0; j < new_atts.size(); ++j){
+				if (new_atts[i] == new_atts[j]){
+					new_atts.erase(new_atts.begin() + i);
+					continue;
+				}
+			}
+		}
+
+		//currently all returned relations are called TEMP
+		Relation new_r("TEMP", new_atts);
+		return new_r;
 	}
 }

DBEngine.h

@@ -21,7 +21,7 @@ public:
 	Relation selection(string attName, string s, Relation r);
 	Relation projection(vector<string> input, Relation r);
 	void rename(Relation& r, vector<string> oldnames, vector<string> newnames);
-	Relation setUnion();
+	Relation setUnion(Relation r1, Relation r2);
 	//void setDiff();
 	//void crossProduct();
 };

Relation.cpp

@@ -21,6 +21,16 @@ Attribute Relation::operator[](int i){
 	return att[i]; 
 }
 
+vector<string> Relation::getTuple(int index){
+	vector<string> temp;
+
+	for (int i = 0; i < att.size(); ++i){
+		temp.push_back(att[i][index]);
+	}
+
+	return temp;
+}
+
 vector<Attribute> Relation::getAttributes(){ 
 	return att; 
 }

Relation.h

@@ -13,6 +13,7 @@ public:
 	Relation(string n, vector<Attribute> a);
 	string getTableName();
 	Attribute operator[](int i);
+	vector<string> getTuple(int index);
 	vector<Attribute> getAttributes();
 	vector<string> getAttributeNames();
 	Attribute& getAttributeByName(string s);

test.cpp

@@ -29,6 +29,32 @@ int main() {
 	
 	engine.createTable("Food", v);
 
-	Relation r = equality("Breakfast", "Pancakes", engine.getTableFromName("Food"));
-	r.display();
+	Attribute att4("SecondBreakfast", "VARCHAR(20)", true);
+	Attribute att5("SecondLunch", "VARCHAR(20)", false);
+	Attribute att6("SecondDinner", "VARCHAR(20)", false);
+	
+	att4.addCell("Pancakes");
+	att4.addCell("Bacon");
+	att4.addCell("Eggs");
+	att5.addCell("Turkey Sandwich");
+	att5.addCell("Pasta Salad");
+	att5.addCell("Taco");
+	att6.addCell("Steak");
+	att6.addCell("Fajitas");
+	att6.addCell("Spaghetti");
+	
+	vector<Attribute> v2;
+	v2.push_back(att4);
+	v2.push_back(att5);
+	v2.push_back(att6);
+	
+	engine.createTable("MoarFood", v2);
+
+	vector<string> test = engine.getTableFromName("Food").getTuple(1);
+
+	for (int i = 0; i < test.size(); ++i){
+		cout << test[i] << " ";
+	}
+
+	//engine.setUnion(engine.getTableFromName("Food"), engine.getTableFromName("MoarFood")).display();
 }