Update db_engine.cpp

db_engine.cpp

@@ -1,12 +1,50 @@
 #include "db_engine.h"
 
+using namespace std;
+
 db_engine::db_engine(){
 	//
 }
 
 //create a new table in memory
-db_engine::createCmd(){
-	////
+//creates a vector 
+//DONE
+void db_engine::createCmd(string tableName, vector<string> attributes, vector<string> pkeys){
+	string output = "";
+	output += "CREATE TABLE " + tableName + " (";
+	
+	vector<string>::iterator it = attributes.begin();
+	while (it != attributes.end()){
+		if (it == attributes.begin())
+			if ((it + 1) != attributes.end())
+				output += *it + ",";
+			else
+				output += *it;
+		else
+			output+= " " + *it;
+		
+		++it;
+	}
+	
+	output += ") PRIMARY KEY (";
+	
+	vector<string>::iterator it2 = pkeys.begin();
+	while (it2 != pkeys.end()){
+		if (it2 == pkeys.begin())
+			if ((it2 + 1) != pkeys.end())
+				output += *it2 + ",";
+			else
+				output += *it2;
+		else
+			output+= " " + *it2;
+		
+		++it2;
+	}
+	
+	output += ");";
+	
+	cout << output;
+	//cmdList.push_back(output);
 }
 	
 //open a txt file, parse SQL script, load data in table
@@ -14,42 +52,92 @@ db_engine::createCmd(){
 	//
 //}
 
-//save all the commands to the db text file
+//should write cmdList to a .txt file
+//DONE
 void db_engine::saveCmd(){
-	//
+	ofstream dbCmdFile;
+	dbCmdFile.open("dbCmds.txt", ios_base::app);
+	
+	vector<string>::iterator it = cmdList.begin();
+	while (it != cmdList.end()){
+		dbCmdFile << *it << "\n";
+		++it;
 	}
 	
-//display the table currently stored in memory
-void db_engine::showCmd(){
-	//
+	cmdList.clear();
+}
+
+//display the database
+//DONE
+void db_engine::showCmd(string tableName){
+	cmdList.push_back("SHOW " + tableName + "");
 }
 
 //add a tuple to a table in the memory
+//BECCA
 void db_engine::insertQuery(){
-	//
+	//table.push_back();
 }
 
 //remove a tuple from a table in the memory
+//BECCA
 void db_engine::deleteQuery(){
 	//
 }
 
 //search and return one more tuples from a table in the memory
+//WILLIAM
 void db_engine::selectQuery(){
 	//
 }
 
 //return a subset of attributes (columns)
-void db_engine::projectQuery(){
-	//
+//BRANDON
+vector<string> db_engine::projectQuery(vector< vector<string> > table, vector<string> attributes, string query){
+	/*
+		So basically this is what's going on:
+		- Take the table to iterate through, this is the 2D vector (input 1)
+		- Take the vector of attributes that pertains to the respective table (input 2)
+		- Take a string that will be used for the program to search for in the attributes (input 3)
+		- In the attributes vector, iterate through each attribute until the attribute (string) matches the input query
+		- For every iterator, have a counter that counts how many attributes are skipped over in the vector until the attribute is found
+		- This counter will be used to iterate through each vector (row) in the list, skip over that many attributes, and push that into a result vector
+		- Once all vector's elements at the specified attribute are pushed back, return the result vector
+	*/
+	int counter = 0; //counter for iterating through the attributes, initialized at 0 for reasons
+	vector<string> result;
+
+	//Loop through the vector until we have found a string in it that matches the query
+	for(int i=0; i < attributes.size(); i++){
+		counter++;
+		if(attributes[i] == query)
+			break;
+		else
+			continue;
+	}
+	
+	//So let's say we have a 2-D Vector (the table) that contains all of the rows, we iterate through each row
+	std::vector< std::vector<int> >::const_iterator row; 
+    std::vector<int>::const_iterator col; 
+
+    for (row = table.begin(); row != table.end(); ++row) { 
+		//Instead of col != row->end() we have it counter, in order for the program to access the correct data under the correct attribute
+		for (col = row->begin(); col != counter; col++) {
+			result.push_back(col); //Now we store that row's attribute into the result vector
+		}
+    }
+	
+	return result;
 }
 
 //each row in the first table is paired with all the rows in the second table
-void db_engine::productQuery(){
+//BRANDON
+vector< vector<string> > db_engine::productQuery(vector< vector<string> > table_1, vector< vector<string> > table_2){
 	//
 }
 
 //true if relations have the same # of attributes and each attribute must be from the same domain
+//WILLIAM
 bool db_engine::unionComp(){
 	return false;
 }