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#include "SqliteDB.h"
#include <iostream>
#include <sstream>
#include <cstdlib>
#include <unistd.h> //for sleep()
//A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
SqliteDBexception::SqliteDBexception() throw() {}
SqliteDBexception::SqliteDBexception(const char* s) throw() {msg = s;}
SqliteDBexception::SqliteDBexception (const string s) throw() {msg = s;}
SqliteDBexception::~SqliteDBexception() throw() {}
const char* SqliteDBexception::what() const throw() {return msg.c_str();}
SqliteDB::SqliteDB(): dbPtr(NULL)
{}
SqliteDB::~SqliteDB()
{
close();
}
void SqliteDB::close()
{
sqlite3_close(dbPtr);
}
int SqliteDB::last_insert_rowid()
{
return sqlite3_last_insert_rowid(dbPtr);
}
/**
* @throw SqliteDBexception if cannot open db.
*/
void SqliteDB::open(const char *filename)
{
if( sqlite3_open(filename, &dbPtr))
{
throw SqliteDBexception("open::Cannot open database file");
}//true = could not open db. false = no errors
}
void SqliteDB::open(const string &filename)
{
open(filename.c_str());
}
//this is used for debugging.
//print the resutls from query()
void SqliteDB::printResults(const vector<vector<string> > &v)
{
for(vector<vector<string> >::const_iterator i = v.begin(); i != v.end(); ++i)
{
for(vector<string>::const_iterator j = (*i).begin(); j != (*i).end(); ++j)
cout << *j << "\t";
cout << endl;
}
}
/**
* Returns the results of an SQL query as an array of strings.
* Null values are returned as the string "NULL"
* @parm query: sql string to run
* @return 2d array of results w/o any table heading.
*/
vector<vector<string> > SqliteDB::query(const char* query)
{
sqlite3_stmt *statement;
vector<vector<string> > results;
int queryErrorCode;
queryErrorCode =sqlite3_prepare_v2(dbPtr, query, -1, &statement, 0);
while ( queryErrorCode == SQLITE_BUSY)
{
cout << "Database is busy, sleeping for 5sec." << endl;
sleep(5);
cout << "Re-running sql:" << query << endl;
queryErrorCode = sqlite3_prepare_v2(dbPtr, query, -1, &statement, 0);
}//while db is busy.
if(queryErrorCode == SQLITE_OK)
{
int cols = sqlite3_column_count(statement);
//The commented-out line can be used to get the header row (the names of the columns)
//const char *sqlite3_column_name(sqlite3_stmt*, int N); gets header infor for nth col(starting from zero???).
int result = 0;
while(true)
{
result = sqlite3_step(statement);
if(result == SQLITE_ROW)
{
vector<string> values;
for(int col = 0; col < cols; col++)
{
char *resultsPtr = (char*)sqlite3_column_text(statement, col);
if ( resultsPtr)
values.push_back(resultsPtr);
else
values.push_back("NULL");
}//for every col in the current row.
results.push_back(values);
}//if there are results
else
{
break;
}
}//while there are more rows
sqlite3_finalize(statement);//free up the memory.
}//if no errors
else
{
string error = sqlite3_errmsg(dbPtr);
stringstream s;
s << "SqliteDB ERROR:: ." << query << ". " << error << endl;
cout << s.str().c_str() << endl;
throw SqliteDBexception(s.str());
}//else there was errors running the sql statment
return results;
}//query
vector<vector<string> > SqliteDB::query(const string &q)
{
return query(q.c_str());
}
/**
* For queries that return 1 int (example: select count(*) form...where...)
*/
int SqliteDB::queryAsInteger(const char* q)
{
vector<vector<string> > result = query(q);
if ( result.size() != 1 && result[0].size() !=1 )
throw SqliteDBexception("queryAsInteger::Query contains more than 1 result");
return atoi(result[0][0].c_str());
}
/**
* For queries that return 1 floating-point number (example: select avg(*) form...where...)
*/
double SqliteDB::queryAsFloat(const char* q)
{
vector<vector<string> > result = query(q);
if ( result.size() != 1 && result[0].size() !=1 )
throw SqliteDBexception("queryAsFloat::Query contains more than 1 result");
return atof(result[0][0].c_str());
}
/**
* For queries that return 1 column of numerical data.
*/
vector<double> SqliteDB::queryAsFloatArray(const char *q)
{
vector<vector<string> > result = query(q);
vector<double> ans;
ans.resize(result.size());
for(int i = 0; i < result.size(); ++i)
{
if ( result[i].size() != 1)
throw SqliteDBexception("queryAsFloatArray::Query contains more than 1 column");
if( result[i][0].compare("NULL") == 0)
ans[i] = 0.0;
else
ans[i] = atof(result[i][0].c_str());
}//for i.
return ans;
}//queryAsFloatArray
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