dmspine64backup/DBEngine.cpp

#include <fstream>
#include <iostream>
#include <vector>
#include "DBEngine.h"

DBEngine::DBEngine(){
	size = 0;
}

void DBEngine::createTable(string n){
	Relation r(n);
	tables.push_back(r);
	size++;
}

void DBEngine::createTable(string n, vector<Attribute> a){
	Relation r(n, a);
	tables.push_back(r);
	size++;
}
	
void DBEngine::createTable(Relation r){ 
	tables.push_back(r); 
	size++;
}
	
vector<Relation> DBEngine::getRelations(){ 
	return tables; 
}

//To check if a relation name is already used.
bool DBEngine::isRelation(string n){
	for(int i = 0; i < tables.size(); i++){
		if (tables[i].getTableName() == n){
			return true;
		}
	}
	return false;
}
	
Relation& DBEngine::getTableFromName(string n){
	for(int i = 0; i < tables.size(); i++){
		if (tables[i].getTableName() == n){
			return tables[i];
		}
	}
}

//currently writes nothing meaningful
void DBEngine::saveToFile(vector<string> cmds){ 
	ofstream file;
	file.open("savefile.db");
	
	for(int i = 0; i < cmds.size(); ++i){
		file << cmds[i] << endl;
	}
	
	file.close();
}

//assumes that all attribute titles are unique
Relation DBEngine::projection(vector<string> input, Relation r){
	
	
//	for(int i = 0; i < input.size(); i++) {
//		it = find(r.getAttributes().begin(), r.getAttributes().end(), input[i])
		
		//if(r[i].getName == input[])
//	}
}

//test error matching
void DBEngine::rename(Relation& r, vector<string> oldnames, vector<string> newnames){
	if (oldnames.size() != newnames.size()) {
		cout << "FAILURE TO RENAME: number of attributes do not match.\n";
		return;
	}
	
	else if (oldnames != r.getAttributeNames()) {
		cout << "FAILURE TO RENAME: the attributes to be renamed do not exist in the relation.\n";
		return;
	}
	
	else {
		for(int i = 0; i < oldnames.size(); ++i){
			r.renameAttribute(oldnames[i], newnames[i]);
		}
	}
}