diff --git a/Parser.cpp b/Parser.cpp
index e7c8da1..2716df4 100644
--- a/Parser.cpp
+++ b/Parser.cpp
@@ -42,13 +42,313 @@ void displayTokenList(vector<string> input)
 	}
 }
 
+Relation condition(vector<string> input, Relation &r)
+{
+	Relation rfinal = r;
+	Attribute a1 = r.getAttributeByName(input[0]);
+	input.erase(input.begin());
+	string op = input[0];
+	input.erase(input.begin());
+	Attribute a2;
+	string c;
+	//cout << input[0] << endl;
+	if(input[0].at(0) == '\"')
+	{
+		c = input[0].substr(1, input[0].find_last_of("\"") - 1);
+		//cout << c << endl;
+	}
+	if(r.isAttribute(input[0]))
+	{
+		a2 = r.getAttributeByName(input[0]);
+		input.erase(input.begin());
+		for(int i = 0; i < r.getAttributes().size(); ++i)
+		{
+			if(r.getAttributes()[i].getName() == a1.getName())
+			{
+				/*
+				for(int j = 0; j < r.getAttributeByName(a1.getName()).getValues().size; ++j)
+				{
+					if(r.getAttributeByName(a1.getName()).getValues()[j] == )
+					{
+						rfinal.insertTuple(r.getTuple(j));
+					}
+				}*/
+				if(op == "==")
+				{
+					for(int x = 0; x < r.getAttributeByName(a1.getName()).getSize(); ++x)
+					{
+						if(r.getAttributeByName(a1.getName()).getValues()[x] != r.getAttributeByName(a2.getName()).getValues()[x])
+						{
+							rfinal.removeTuple(x);
+							//rfinal.insertAttributes(a);
+						}
+					}
+				}
+				else if(op == "!=")
+				{
+					for(int x = 0; x < r.getAttributeByName(a1.getName()).getSize(); ++x)
+					{
+						if(r.getAttributeByName(a1.getName()).getValues()[x] == r.getAttributeByName(a2.getName()).getValues()[x])
+						{
+							rfinal.removeTuple(x);
+							//rfinal.insertAttributes(a);
+						}
+					}
+				}
+				else if(op == ">=")
+				{
+					if(r.getAttributeByName(a1.getName()).getType() == "INTEGER" && r.getAttributeByName(a2.getName()).getType() == "INTEGER")
+					{
+						for(int x = 0; x < r.getAttributeByName(a1.getName()).getSize(); ++x)
+						{
+							if(stoi(r.getAttributeByName(a1.getName()).getValues()[x]) < stoi(r.getAttributeByName(a2.getName()).getValues()[x]))
+							{
+								rfinal.removeTuple(x);
+								//rfinal.insertAttributes(a);
+							}
+						}
+					}
+					else
+					{
+						cout << "Attribute type is not an INTEGER." << endl;
+						exit(1);
+					}
+				}
+				else if(op == "<=")
+				{
+					if(r.getAttributeByName(a1.getName()).getType() == "INTEGER" && r.getAttributeByName(a2.getName()).getType() == "INTEGER")
+					{
+						for(int x = 0; x < r.getAttributeByName(a1.getName()).getSize(); ++x)
+						{
+							if(stoi(r.getAttributeByName(a1.getName()).getValues()[x]) > stoi(r.getAttributeByName(a2.getName()).getValues()[x]))
+							{
+								rfinal.removeTuple(x);
+								//rfinal.insertAttributes(a);
+							}
+						}
+					}
+					else
+					{
+						cout << "Attribute type is not an INTEGER." << endl;
+						exit(1);
+					}
+				}
+				else if(op == ">")
+				{
+					
+					if(r.getAttributeByName(a1.getName()).getType() == "INTEGER" && r.getAttributeByName(a2.getName()).getType() == "INTEGER")
+					{
+						for(int x = 0; x < r.getAttributeByName(a1.getName()).getSize(); ++x)
+						{
+							if(stoi(r.getAttributeByName(a1.getName()).getValues()[x]) <= stoi(r.getAttributeByName(a2.getName()).getValues()[x]))
+							{
+								rfinal.removeTuple(x);
+								//rfinal.insertAttributes(a);
+							}
+						}
+					}
+					else
+					{
+						cout << "Attribute type is not an INTEGER." << endl;
+						exit(1);
+					}
+				}
+				else if(op == "<")
+				{
+					if(r.getAttributeByName(a1.getName()).getType() == "INTEGER" && r.getAttributeByName(a2.getName()).getType() == "INTEGER")
+					{
+						for(int x = 0; x < r.getAttributeByName(a1.getName()).getSize(); ++x)
+						{
+							if(stoi(r.getAttributeByName(a1.getName()).getValues()[x]) >= stoi(r.getAttributeByName(a2.getName()).getValues()[x]))
+							{
+								rfinal.removeTuple(x);
+								//rfinal.insertAttributes(a);
+							}
+						}
+					}
+					else
+					{
+						cout << "Attribute type is not an INTEGER." << endl;
+						exit(1);
+					}
+				}
+			}
+		}
+	}
+	else
+	{
+		input.erase(input.begin());
+		if(op == "==")
+		{
+			for(int i = 0; i < r.getAttributes().size(); ++i)
+			{
+				if(r.getAttributes()[i].getName() == a1.getName())
+				{
+					for(int j = 0; j < r.getAttributeByName(a1.getName()).getValues().size(); ++j)
+					{
+						if(r.getAttributeByName(a1.getName()).getValues()[j] != c)
+						{
+							rfinal.removeTuple(j);
+						}
+					}
+				}
+			}
+		}
+		else if(op == "!=")
+		{
+			for(int i = 0; i < r.getAttributes().size(); ++i)
+			{
+				if(r.getAttributes()[i].getName() == a1.getName())
+				{
+					for(int j = 0; j < r.getAttributeByName(a1.getName()).getValues().size(); ++j)
+					{
+						if(r.getAttributeByName(a1.getName()).getValues()[j] == c)
+						{
+							rfinal.removeTuple(j);
+						}
+					}
+				}
+			}
+		}
+		else if(op == ">=")
+		{
+			if(r.getAttributeByName(a1.getName()).getType() == "INTEGER")
+			{
+				for(int i = 0; i < r.getAttributes().size(); ++i)
+				{
+					if(r.getAttributes()[i].getName() == a1.getName())
+					{
+						for(int j = 0; j < r.getAttributeByName(a1.getName()).getValues().size(); ++j)
+						{
+							if(stoi(r.getAttributeByName(a1.getName()).getValues()[j]) < stoi(c))
+							{
+								rfinal.removeTuple(j);
+							}
+						}
+					}
+				}
+			}
+			else
+			{
+				cout << "Attribute type is not an INTEGER." << endl;
+				exit(1);
+			}
+		}
+		else if(op == "<=")
+		{
+			if(r.getAttributeByName(a1.getName()).getType() == "INTEGER")
+			{
+				for(int i = 0; i < r.getAttributes().size(); ++i)
+				{
+					if(r.getAttributes()[i].getName() == a1.getName())
+					{
+						for(int j = 0; j < r.getAttributeByName(a1.getName()).getValues().size(); ++j)
+						{
+							if(stoi(r.getAttributeByName(a1.getName()).getValues()[j]) > stoi(c))
+							{
+								rfinal.removeTuple(j);
+							}
+						}
+					}
+				}
+			}
+			else
+			{
+				cout << "Attribute type is not an INTEGER." << endl;
+				exit(1);
+			}
+		}
+		else if(op == ">")
+		{
+			
+			if(r.getAttributeByName(a1.getName()).getType() == "INTEGER")
+			{
+				for(int i = 0; i < r.getAttributes().size(); ++i)
+				{
+					if(r.getAttributes()[i].getName() == a1.getName())
+					{
+						for(int j = 0; j < r.getAttributeByName(a1.getName()).getValues().size(); ++j)
+						{
+							if(stoi(r.getAttributeByName(a1.getName()).getValues()[j]) <= stoi(c))
+							{
+								rfinal.removeTuple(j);
+							}
+						}
+					}
+				}
+			}
+			else
+			{
+				cout << "Attribute type is not an INTEGER." << endl;
+				exit(1);
+			}
+		}
+		else if(op == "<")
+		{
+			
+			if(r.getAttributeByName(a1.getName()).getType() == "INTEGER")
+			{
+				for(int i = 0; i < r.getAttributes().size(); ++i)
+				{
+					if(r.getAttributes()[i].getName() == a1.getName())
+					{
+						for(int j = 0; j < r.getAttributeByName(a1.getName()).getValues().size(); ++j)
+						{
+							if(stoi(r.getAttributeByName(a1.getName()).getValues()[j]) >= stoi(c))
+							{
+								rfinal.removeTuple(j);
+							}
+						}
+					}
+				}
+			}
+			else
+			{
+				cout << "Attribute type is not an INTEGER." << endl;
+				exit(1);
+			}
+		}
+	}
+	return rfinal;
+}
+
 tuple<vector<string>, Relation> expression(vector<string> input, DBEngine &engine)
 {
 	Relation rfinal("TEMP");
 	tuple<vector<string>, Relation> t(input, rfinal);
 	if(input[0] == "select")
 	{
-		
+		/*
+		cout << "Not yet implemented." << endl;
+		exit(1);
+		*/
+		input.erase(input.begin());
+		vector<string> s;
+		Relation r("TEMP");
+		if(input[0] == "(")
+		{
+			input.erase(input.begin());
+			while(input[0] != ")")
+			{
+				s.push_back(input[0]);
+				input.erase(input.begin());
+			}
+			input.erase(input.begin());
+			if(engine.isRelation(input[0]))
+			{
+				r = condition(s, engine.getTableFromName(input[0]));
+				input.erase(input.begin());
+			}
+			else if(input[0] == "(")
+			{
+				tuple<vector<string>, Relation> t = expression(input, engine);
+				r = condition(s, get<1>(t));
+				input.erase(input.begin());
+			}
+		}
+		get<0>(t) = input;
+		get<1>(t) = r;
+		return t;
 	}
 	
 	else if(input[0] == "project")
diff --git a/Relation.cpp b/Relation.cpp
index 3f9fb7b..bf32b20 100755
--- a/Relation.cpp
+++ b/Relation.cpp
@@ -63,6 +63,16 @@ Attribute& Relation::getAttributeByName(string s) {
 	cout << "Failure to return: the requested attribute does not exist.";
 }
 
+bool Relation::isAttribute(string s) {
+	for(int i = 0; i < size; ++i){
+		if (att[i].getName() == s) {
+			return true;
+		}
+	}
+	return false;
+	//cout << "Failure to return: the requested attribute does not exist.";
+}
+
 void Relation::renameAttribute(string oldstr, string newstr){
 	this->getAttributeByName(oldstr).setName(newstr);
 }
diff --git a/Relation.h b/Relation.h
index 431d634..4c7e1e2 100755
--- a/Relation.h
+++ b/Relation.h
@@ -19,6 +19,7 @@ public:
 	vector<Attribute> getAttributes();
 	vector<string> getAttributeNames();
 	Attribute& getAttributeByName(string s);
+	bool isAttribute(string s);
 	void renameAttribute(string oldstr, string newstr);
 	int getSize();
 	void display();
diff --git a/test b/test
index b0e69f8..9b3ff7f 100755
Binary files a/test and b/test differ