Kompex SQLite Wrapper for C++ - Examples

Here you can see some examples.

It shows a part of the functionality of the wrapper and how you can use it.

You can find more examples in the example application (contained in download package).

1. open a database and create a statement instance for sql queries/statements

// open database

Kompex::SQLiteDatabase *pDatabase = new Kompex::SQLiteDatabase("test.db", SQLITE_OPEN_READWRITE, 0);

// create statement instance for sql queries/statements

Kompex::SQLiteStatement *pStmt = new Kompex::SQLiteStatement(pDatabase);

2. create a new table and fill it with data

// create table and insert some data

pStmt->SqlStatement("CREATE TABLE user    \

( \

userID INTEGER NOT NULL PRIMARY KEY,      \

lastName VARCHAR(50) NOT NULL,    \

firstName VARCHAR(50), age INTEGER\

)");

pStmt->SqlStatement("INSERT INTO user (userID, lastName, firstName, age) \

 VALUES (1, 'Lehmann', 'Jamie', 20)");

pStmt->SqlStatement("INSERT INTO user (userID, lastName, firstName, age) \

 VALUES (2, 'Burgdorf', 'Peter', 55)");

pStmt->SqlStatement("INSERT INTO user (userID, lastName, firstName, age) \

 VALUES (3, 'Lehmann', 'Fernando', 18)");

pStmt->SqlStatement("INSERT INTO user (userID, lastName, firstName, age) \

 VALUES (4, 'Lehmann', 'Carlene', 17)");

3. use some aggregate functions

pStmt->SqlAggregateFuncResult("SELECT COUNT(*) FROM user WHERE lastName = 'Lehmann';");

pStmt->SqlAggregateFuncResult("SELECT COUNT(weight) FROM user;");

pStmt->SqlAggregateFuncResult("SELECT MAX(age) FROM user;");

pStmt->SqlAggregateFuncResult("SELECT MIN(age) FROM user;");

pStmt->SqlAggregateFuncResult("SELECT ***G(age) FROM user;");

pStmt->SqlAggregateFuncResult("SELECT SUM(age) FROM user;");

pStmt->SqlAggregateFuncResult("SELECT TOTAL(age) FROM user;");

4. execute and process a sql query

pStmt->Sql("SELECT * FROM user WHERE firstName = 'Jamie';");

// process all results

while(pStmt->FetchRow())

{

std::cout << "first name: " << pStmt->GetColumnInt(0) << std::endl;

std::cout << "last name: " << pStmt->GetColumnString(1) << std::endl;

std::cout << "first name: " << pStmt->GetColumnString(2) << std::endl;

}

// do not forget to clean-up

pStmt->FreeQuery();

5. execute a simple transaction

// if an error occurs, a rollback is automatically performed

pStmt->BeginTransaction();

pStmt->Transaction("INSERT INTO user(userID, firstName, age) VALUES (10, 'Makoto', 23)");

pStmt->Transaction("INSERT INTO user(userID, firstName, age) VALUES (11, 'Yura', 20)";

pStmt->Transaction("INSERT INTO user(userID, firstName, age) VALUES (12, 'Peter', 63)");

pStmt->CommitTransaction();

6. here you can see the exception handling

try

{

// table structure: userID INTEGER NOT NULL PRIMARY KEY, lastName VARCHAR(50)

pStmt->SqlStatement("INSERT INTO user(userID, lastName) VALUES(1, 'Lehmann')");

// the following line will throw an exception because the primary key is not unique

pStmt->SqlStatement("INSERT INTO user(userID, lastName) VALUES(1, 'Bergmann')");

}

catch(Kompex::SQLiteException &exception)

{

std::cerr << "Exception Occured" << std::endl;

exception.Show();

}

7. work with a memory database

Kompex::SQLiteDatabase *pDatabase = new Kompex::SQLiteDatabase("scores.db", SQLITE_OPEN_READWRITE, 0);

// move database to memory, so that we are work on the memory database hence

pDatabase->MoveDatabaseToMemory();

Kompex::SQLiteStatement *pStmt = new Kompex::SQLiteStatement(pDatabase);

// insert some data sets into the memory database

pStmt->SqlStatement("INSERT INTO score(id, lastScore, avgScore) VALUES(1, 429, 341)");

pStmt->SqlStatement("INSERT INTO score(id, lastScore, avgScore) VALUES(2, 37, 44)");

pStmt->SqlStatement("INSERT INTO score(id, lastScore, avgScore) VALUES(3, 310, 280)");

// save the memory database to a file

// if you don't do it, all database changes will be lost after closing the memory database

pDatabase->SaveDatabaseFromMemoryToFile("newScores.db");

8. get some result values via column name (more flexible and a little bit slower than the common way)

pStmt->Sql("SELECT * FROM user WHERE lastName = 'Lehmann';");

// process all results

while(pStmt->FetchRow())

{

std::cout << "firstName: " << pStmt->GetColumnString("firstName") << std::endl;

std::cout << "age: " << pStmt->GetColumnInt("age") << std::endl;

}

// do not forget to clean-up

pStmt->FreeQuery();

9. two possibilities to update data in the database

// the first way

pStmt->SqlStatement("UPDATE user SET weight=51.5, age=18 WHERE firstName='Carlene'");

// the second way - with a prepared statement

pStmt->Sql("UPDATE user SET lastName=@lastName, age=@age WHERE userID=@userID");

// bind an integer to the prepared statement

pStmt->BindString(1, "Urushihara");// bind lastName

pStmt->BindInt(2, 56);// bind age

pStmt->BindInt(3, 2);// bind userID

// execute it and clean-up

pStmt->ExecuteAndFree();