Using SQLite in C++ with Code::blocks

What you will need:
-Basic C++ and sql knowledge
-sqlite (Download)

Introduction
sqlite is an embedded sql database engine. Unlike most other sql databases,sqlite does not have a separate server process,but instead reads and writes directly to ordinary disk files. This makes sqlite an easy and good solution to store data for your application.

opening a database
The first thing you need to do,is open a database. If the database does not exist yet,it will be created.

 
       1 
       sqlite3 *database; 
     
   2 
    sqlite3_open("Database.sqlite",&database);

The first argument is the filename,the second is the sqlite3 database handle.
If everything goes right,sqlITE_OKis returned.

Query's
Once the database is opened,you can actually start doing something. The following code shows how:

01 sqlite3_stmt *statement;

02

03 
       if(sqlite3_prepare_v2(database,"CREATE TABLE a (b INTEGER,c INTEGER);"sqlITE_OK)

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      {

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      intcols = sqlite3_column_count(statement);

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      result = 0;

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      while(true)

08 
      09 
      result = sqlite3_step(statement);

10

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      (result == sqlITE_ROW)

12 
      13 
      for(col = 0; col < cols; col++)

14 
      15 
      string s = (char*)sqlite3_column_text(statement,col);

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      //do something with it

17 
      }

18 
      }

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      else

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      21 
      break;





      sqlite3_finalize(statement);

26 
      }

#include "Database.h" #include <iostream> Database::Database(char* filename) { database = NULL; open(filename); } Database::~Database() { } bool Database::open(char* filename) { if(sqlite3_open(filename,&database) == sqlITE_OK) return true; return false; } vector<vector<string> > Database::query(char* query) { sqlite3_stmt *statement; vector<vector<string> > results; if(sqlite3_prepare_v2(database,query,0) == sqlITE_OK) { int cols = sqlite3_column_count(statement); int result = 0; while(true) { result = sqlite3_step(statement); if(result == sqlITE_ROW) { vector<string> values; for(int col = 0; col < cols; col++) { std::string val; char * ptr = (char*)sqlite3_column_text(statement,col); if(ptr) { val = ptr; } else val = ""; // this can be commented out since std::string val; // initialize variable 'val' to empty string anyway values.push_back(val); // now we will never push NULL } results.push_back(values); } else { break; } } sqlite3_finalize(statement); } string error = sqlite3_errmsg(database); if(error != "not an error") cout << query << " " << error << endl; return results; } void Database::close() { sqlite3_close(database); }

#include <iostream> #include "Database.h" using namespace std; int main() { Database *db; db = new Database("Database.sqlite"); db->query("CREATE TABLE a (a INTEGER,b INTEGER);"); db->query("INSERT INTO a VALUES(1,2);"); db->query("INSERT INTO a VALUES(5,4);"); vector<vector<string> > result = db->query("SELECT a,b FROM a;"); for(vector<vector<string> >::iterator it = result.begin(); it < result.end(); ++it) { vector<string> row = *it; cout << "Values: (A=" << row.at(0) << ",B=" << row.at(1) << ")" << endl; } db->close(); }

Using SQLite in C++ with Code::blocks

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