// Close the SQLite database connection.
Database::~Database() noexcept // nothrow
{
const int ret = sqlite3_close(mpSQLite);
// Only case of error is SQLITE_BUSY: "database is locked" (some statements are not finalized)
// Never throw an exception in a destructor :
SQLITECPP_ASSERT(SQLITE_OK == ret, "database is locked"); // See SQLITECPP_ENABLE_ASSERT_HANDLER
}
// Close the SQLite database connection.
Database::~Database() noexcept { // nothrow
const int ret = sqlite3_close ( mpSQLite );
// Avoid unreferenced variable warning when build in release mode
( void ) ret;
// Only case of error is SQLITE_BUSY: "database is locked" (some statements are not finalized)
// Never throw an exception in a destructor :
SQLITECPP_ASSERT ( SQLITE_OK == ret, "database is locked" ); // See SQLITECPP_ENABLE_ASSERT_HANDLER
}
// Safely rollback the transaction if it has not been committed.
Transaction::~Transaction() noexcept // nothrow
{
if (false == mbCommited)
{
try
{
mDatabase.exec("ROLLBACK");
}
catch (SQLite::Exception& e)
{
// Never throw an exception in a destructor
SQLITECPP_ASSERT(false, e.what()); // See SQLITECPP_ENABLE_ASSERT_HANDLER
}
}
}
/**
* @brief Decrement the ref counter and finalize the sqlite3_stmt when it reaches 0
*/
Statement::Ptr::~Ptr() noexcept // nothrow
{
assert(NULL != mpRefCount);
assert(0 != *mpRefCount);
// Decrement and check the reference counter of the sqlite3_stmt
--(*mpRefCount);
if (0 == *mpRefCount)
{
// If count reaches zero, finalize the sqlite3_stmt,
// as no Statement not Column objet use it anymore
int ret = sqlite3_finalize(mpStmt);
// Never throw an exception in a destructor
SQLITECPP_ASSERT(SQLITE_OK == ret, sqlite3_errmsg(mpSQLite)); // See SQLITECPP_ENABLE_ASSERT_HANDLER
// and delete the reference counter
delete mpRefCount;
mpRefCount = NULL;
mpStmt = NULL;
}
// else, the finalization will be done later, by the last object
}
int main ()
{
// Basic example (1/6) :
try
{
// Open a database file in readonly mode
SQLite::Database db(filename_example_db3); // SQLITE_OPEN_READONLY
std::cout << "SQLite database file '" << db.getFilename().c_str() << "' opened successfully\n";
// Test if the 'test' table exists
bool bExists = db.tableExists("test");
std::cout << "SQLite table 'test' exists=" << bExists << "\n";
// Get a single value result with an easy to use shortcut
std::string value = db.execAndGet("SELECT value FROM test WHERE id=2");
std::cout << "execAndGet=" << value.c_str() << std::endl;
// Compile a SQL query, containing one parameter (index 1)
SQLite::Statement query(db, "SELECT id as test_id, value as test_val, weight as test_weight FROM test WHERE weight > ?");
std::cout << "SQLite statement '" << query.getQuery().c_str() << "' compiled (" << query.getColumnCount () << " columns in the result)\n";
// Bind the integer value 2 to the first parameter of the SQL query
query.bind(1, 2);
std::cout << "binded with integer value '2' :\n";
// Loop to execute the query step by step, to get one a row of results at a time
while (query.executeStep())
{
// Demonstrate how to get some typed column value (and the equivalent explicit call)
int id = query.getColumn(0); // = query.getColumn(0).getInt()
//const char* pvalue = query.getColumn(1); // = query.getColumn(1).getText()
std::string value2 = query.getColumn(1); // = query.getColumn(1).getText()
int bytes = query.getColumn(1).getBytes();
double weight = query.getColumn(2); // = query.getColumn(2).getInt()
static bool bFirst = true;
if (bFirst)
{
// Show how to get the aliased names of the result columns.
std::string name0 = query.getColumn(0).getName();
std::string name1 = query.getColumn(1).getName();
std::string name2 = query.getColumn(2).getName();
std::cout << "aliased result [\"" << name0.c_str() << "\", \"" << name1.c_str() << "\", \"" << name2.c_str() << "\"]\n";
#ifdef SQLITE_ENABLE_COLUMN_METADATA
// Show how to get origin names of the table columns from which theses result columns come from.
// Requires the SQLITE_ENABLE_COLUMN_METADATA preprocessor macro to be
// also defined at compile times of the SQLite library itself.
name0 = query.getColumn(0).getOriginName();
name1 = query.getColumn(1).getOriginName();
name2 = query.getColumn(2).getOriginName();
std::cout << "origin table 'test' [\"" << name0.c_str() << "\", \"" << name1.c_str() << "\", \"" << name2.c_str() << "\"]\n";
#endif
bFirst = false;
}
std::cout << "row (" << id << ", \"" << value2.c_str() << "\" " << bytes << " bytes, " << weight << ")\n";
}
// Reset the query to use it again
query.reset();
std::cout << "SQLite statement '" << query.getQuery().c_str() << "' reseted (" << query.getColumnCount () << " columns in the result)\n";
// Bind the string value "6" to the first parameter of the SQL query
query.bind(1, "6");
std::cout << "binded with string value \"6\" :\n";
while (query.executeStep())
{
// Demonstrate that inserting column value in a std:ostream is natural
std::cout << "row (" << query.getColumn(0) << ", \"" << query.getColumn(1) << "\", " << query.getColumn(2) << ")\n";
}
}
catch (std::exception& e)
{
std::cout << "SQLite exception: " << e.what() << std::endl;
return EXIT_FAILURE; // unexpected error : exit the example program
}
////////////////////////////////////////////////////////////////////////////
// Object Oriented Basic example (2/6) :
try
{
// Open the database and compile the query
Example example;
// Demonstrate the way to use the same query with different parameter values
example.ListGreaterThan(8);
example.ListGreaterThan(6);
example.ListGreaterThan(2);
}
catch (std::exception& e)
{
std::cout << "SQLite exception: " << e.what() << std::endl;
return EXIT_FAILURE; // unexpected error : exit the example program
}
// The execAndGet wrapper example (3/6) :
try
{
// Open a database file in readonly mode
SQLite::Database db(filename_example_db3); // SQLITE_OPEN_READONLY
std::cout << "SQLite database file '" << db.getFilename().c_str() << "' opened successfully\n";
// WARNING: Be very careful with this dangerous method: you have to
// make a COPY OF THE result, else it will be destroy before the next line
// (when the underlying temporary Statement and Column objects are destroyed)
std::string value = db.execAndGet("SELECT value FROM test WHERE id=2");
std::cout << "execAndGet=" << value.c_str() << std::endl;
}
catch (std::exception& e)
{
std::cout << "SQLite exception: " << e.what() << std::endl;
return EXIT_FAILURE; // unexpected error : exit the example program
}
////////////////////////////////////////////////////////////////////////////
// Simple batch queries example (4/6) :
try
{
// Open a database file in create/write mode
SQLite::Database db("test.db3", SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
std::cout << "SQLite database file '" << db.getFilename().c_str() << "' opened successfully\n";
// Create a new table with an explicit "id" column aliasing the underlying rowid
db.exec("DROP TABLE IF EXISTS test");
db.exec("CREATE TABLE test (id INTEGER PRIMARY KEY, value TEXT)");
// first row
int nb = db.exec("INSERT INTO test VALUES (NULL, \"test\")");
std::cout << "INSERT INTO test VALUES (NULL, \"test\")\", returned " << nb << std::endl;
// second row
nb = db.exec("INSERT INTO test VALUES (NULL, \"second\")");
std::cout << "INSERT INTO test VALUES (NULL, \"second\")\", returned " << nb << std::endl;
// update the second row
nb = db.exec("UPDATE test SET value=\"second-updated\" WHERE id='2'");
std::cout << "UPDATE test SET value=\"second-updated\" WHERE id='2', returned " << nb << std::endl;
// Check the results : expect two row of result
SQLite::Statement query(db, "SELECT * FROM test");
std::cout << "SELECT * FROM test :\n";
while (query.executeStep())
{
std::cout << "row (" << query.getColumn(0) << ", \"" << query.getColumn(1) << "\")\n";
}
db.exec("DROP TABLE test");
}
catch (std::exception& e)
{
std::cout << "SQLite exception: " << e.what() << std::endl;
return EXIT_FAILURE; // unexpected error : exit the example program
}
remove("test.db3");
////////////////////////////////////////////////////////////////////////////
// RAII transaction example (5/6) :
try
{
// Open a database file in create/write mode
SQLite::Database db("transaction.db3", SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
std::cout << "SQLite database file '" << db.getFilename().c_str() << "' opened successfully\n";
db.exec("DROP TABLE IF EXISTS test");
// Exemple of a successful transaction :
try
{
// Begin transaction
SQLite::Transaction transaction(db);
db.exec("CREATE TABLE test (id INTEGER PRIMARY KEY, value TEXT)");
int nb = db.exec("INSERT INTO test VALUES (NULL, \"test\")");
std::cout << "INSERT INTO test VALUES (NULL, \"test\")\", returned " << nb << std::endl;
// Commit transaction
transaction.commit();
}
catch (std::exception& e)
{
std::cout << "SQLite exception: " << e.what() << std::endl;
return EXIT_FAILURE; // unexpected error : exit the example program
}
// Exemple of a rollbacked transaction :
try
{
// Begin transaction
SQLite::Transaction transaction(db);
int nb = db.exec("INSERT INTO test VALUES (NULL, \"second\")");
std::cout << "INSERT INTO test VALUES (NULL, \"second\")\", returned " << nb << std::endl;
nb = db.exec("INSERT INTO test ObviousError");
std::cout << "INSERT INTO test \"error\", returned " << nb << std::endl;
return EXIT_FAILURE; // unexpected success : exit the example program
// Commit transaction
transaction.commit();
}
catch (std::exception& e)
{
std::cout << "SQLite exception: " << e.what() << std::endl;
// expected error, see above
}
// Check the results (expect only one row of result, as the second one has been rollbacked by the error)
SQLite::Statement query(db, "SELECT * FROM test");
std::cout << "SELECT * FROM test :\n";
while (query.executeStep())
{
std::cout << "row (" << query.getColumn(0) << ", \"" << query.getColumn(1) << "\")\n";
}
}
catch (std::exception& e)
{
std::cout << "SQLite exception: " << e.what() << std::endl;
return EXIT_FAILURE; // unexpected error : exit the example program
}
remove("transaction.db3");
////////////////////////////////////////////////////////////////////////////
// Binary blob and in-memory database example (6/6) :
try
{
// Open a database file in create/write mode
SQLite::Database db(":memory:", SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
std::cout << "SQLite database file '" << db.getFilename().c_str() << "' opened successfully\n";
db.exec("DROP TABLE IF EXISTS test");
db.exec("CREATE TABLE test (id INTEGER PRIMARY KEY, value BLOB)");
FILE* fp = fopen(filename_logo_png.c_str(), "rb");
if (NULL != fp)
{
char buffer[16*1024];
void* blob = &buffer;
int size = static_cast<int>(fread(blob, 1, 16*1024, fp));
buffer[size] = '\0';
fclose (fp);
std::cout << "blob size=" << size << " :\n";
// Insert query
SQLite::Statement query(db, "INSERT INTO test VALUES (NULL, ?)");
// Bind the blob value to the first parameter of the SQL query
query.bind(1, blob, size);
std::cout << "blob binded successfully\n";
// Execute the one-step query to insert the blob
int nb = query.exec ();
std::cout << "INSERT INTO test VALUES (NULL, ?)\", returned " << nb << std::endl;
}
else
{
std::cout << "file " << filename_logo_png << " not found !\n";
return EXIT_FAILURE; // unexpected error : exit the example program
}
fp = fopen("out.png", "wb");
if (NULL != fp)
{
const void* blob = NULL;
size_t size;
SQLite::Statement query(db, "SELECT * FROM test");
std::cout << "SELECT * FROM test :\n";
if (query.executeStep())
{
SQLite::Column colBlob = query.getColumn(1);
blob = colBlob.getBlob ();
size = colBlob.getBytes ();
std::cout << "row (" << query.getColumn(0) << ", size=" << size << ")\n";
size_t sizew = fwrite(blob, 1, size, fp);
SQLITECPP_ASSERT(sizew == size, "fwrite failed"); // See SQLITECPP_ENABLE_ASSERT_HANDLER
fclose (fp);
}
}
else
{
std::cout << "file out.png not created !\n";
return EXIT_FAILURE; // unexpected error : exit the example program
}
}
catch (std::exception& e)
{
std::cout << "SQLite exception: " << e.what() << std::endl;
return EXIT_FAILURE; // unexpected error : exit the example program
}
remove("out.png");
std::cout << "everything ok, quitting\n";
return EXIT_SUCCESS;
}
// Close the SQLite database connection.
Database::~Database(void) throw() // nothrow
{
int ret = sqlite3_close(mpSQLite);
// Never throw an exception in a destructor
SQLITECPP_ASSERT (SQLITE_OK == ret, sqlite3_errmsg(mpSQLite)); // See SQLITECPP_ENABLE_ASSERT_HANDLER
}
