Update and rename db_engine.cpp to DBEngine.cpp
This commit is contained in:
Brandon Jackson
parent
b24f5117f4
commit
f5db5ac3ec
2 changed files with 73 additions and 143 deletions
73
DBEngine.cpp
Executable file
73
DBEngine.cpp
Executable file
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#include "DBEngine.h"
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using namespace std;
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DBEngine::DBEngine(){
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//
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}
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//create a new table in memory
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void DBEngine::createCmd(){
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//
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}
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//open a txt file, parse SQL script, load data in table
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//void DBEngine::openCmd(){
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//
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//}
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//should write cmdList to a .txt file
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void DBEngine::saveCmd(){
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//
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}
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//display the database
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void DBEngine::showCmd(){
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//
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}
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//add a tuple to a table in the memory
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void DBEngine::insertQuery(){
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//
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}
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//remove a tuple from a table in the memory
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void DBEngine::deleteQuery(){
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//
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}
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//search and return one more tuples from a table in the memory
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void DBEngine::selectQuery(){
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//
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}
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//return a subset of attributes (columns)
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/*
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vector<string> DBEngine::projectQuery(Relation table, string query){
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/*
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So basically this is what's going on:
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- Take the table to iterate through, this is the relation (input 1)
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- Take a string that will be used for the program to search for in the attributes (input 2)
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- Iterate through each attribute until the attribute (string) matches the input query
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- For every iterator, have a counter that counts how many attributes are skipped over in the vector until the attribute is found
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- 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
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- Once all vector's elements at the specified attribute are pushed back, return the result vector
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for(int i = 0; i < table.getSize(); i++) {
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}
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}
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*/
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//each row in the first table is paired with all the rows in the second table
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void DBEngine::productQuery(){
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//
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}
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//true if relations have the same # of attributes and each attribute must be from the same domain
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bool DBEngine::unionComp(){
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return false;
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}
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143
db_engine.cpp
143
db_engine.cpp
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@ -1,143 +0,0 @@
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#include "db_engine.h"
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using namespace std;
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db_engine::db_engine(){
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//
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}
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//create a new table in memory
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//creates a vector
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//DONE
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void db_engine::createCmd(string tableName, vector<string> attributes, vector<string> pkeys){
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string output = "";
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output += "CREATE TABLE " + tableName + " (";
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vector<string>::iterator it = attributes.begin();
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while (it != attributes.end()){
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if (it == attributes.begin())
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if ((it + 1) != attributes.end())
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output += *it + ",";
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else
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output += *it;
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else
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output+= " " + *it;
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++it;
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}
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output += ") PRIMARY KEY (";
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vector<string>::iterator it2 = pkeys.begin();
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while (it2 != pkeys.end()){
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if (it2 == pkeys.begin())
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if ((it2 + 1) != pkeys.end())
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output += *it2 + ",";
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else
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output += *it2;
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else
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output+= " " + *it2;
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++it2;
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}
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output += ");";
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cout << output;
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//cmdList.push_back(output);
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}
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//open a txt file, parse SQL script, load data in table
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//void db_engine::openCmd(){
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//
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//}
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//should write cmdList to a .txt file
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//DONE
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void db_engine::saveCmd(){
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ofstream dbCmdFile;
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dbCmdFile.open("dbCmds.txt", ios_base::app);
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vector<string>::iterator it = cmdList.begin();
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while (it != cmdList.end()){
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dbCmdFile << *it << "\n";
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++it;
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}
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cmdList.clear();
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}
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//display the database
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//DONE
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void db_engine::showCmd(string tableName){
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cmdList.push_back("SHOW " + tableName + "");
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}
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//add a tuple to a table in the memory
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//BECCA
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void db_engine::insertQuery(){
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//table.push_back();
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}
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//remove a tuple from a table in the memory
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//BECCA
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void db_engine::deleteQuery(){
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//
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}
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//search and return one more tuples from a table in the memory
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//WILLIAM
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void db_engine::selectQuery(){
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//
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}
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//return a subset of attributes (columns)
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//BRANDON
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vector<string> db_engine::projectQuery(vector< vector<string> > table, vector<string> attributes, string query){
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/*
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So basically this is what's going on:
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- Take the table to iterate through, this is the 2D vector (input 1)
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- Take the vector of attributes that pertains to the respective table (input 2)
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- Take a string that will be used for the program to search for in the attributes (input 3)
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- In the attributes vector, iterate through each attribute until the attribute (string) matches the input query
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- For every iterator, have a counter that counts how many attributes are skipped over in the vector until the attribute is found
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- 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
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- Once all vector's elements at the specified attribute are pushed back, return the result vector
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*/
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int counter = 0; //counter for iterating through the attributes, initialized at 0 for reasons
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vector<string> result;
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//Loop through the vector until we have found a string in it that matches the query
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for(int i=0; i < attributes.size(); i++){
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counter++;
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if(attributes[i] == query)
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break;
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else
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continue;
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}
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//So let's say we have a 2-D Vector (the table) that contains all of the rows, we iterate through each row
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std::vector< std::vector<int> >::const_iterator row;
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std::vector<int>::const_iterator col;
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for (row = table.begin(); row != table.end(); ++row) {
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//Instead of col != row->end() we have it counter, in order for the program to access the correct data under the correct attribute
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for (col = row->begin(); col != counter; col++) {
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result.push_back(col); //Now we store that row's attribute into the result vector
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}
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}
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return result;
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}
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//each row in the first table is paired with all the rows in the second table
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//BRANDON
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vector< vector<string> > db_engine::productQuery(vector< vector<string> > table_1, vector< vector<string> > table_2){
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//
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}
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//true if relations have the same # of attributes and each attribute must be from the same domain
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//WILLIAM
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bool db_engine::unionComp(){
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return false;
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}
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