libsqxx

Lightweight, object oriented, fully featured C++ 11 wrapper around libsqlite3.

Notable features

Only minimal overhead over calling the C API functions directly
Contains easy to use functions that get common tasks done quickly, even without experience with sqlite3
Contains methods corresponding directly to the C API functions, so if you are familiar with the C API, that knowledge should translate directly.
Contains support for advanced features like registering callbacks, collation functions of custom SQL functions, fully in C++. For example a lambda functions can be registered as a custom SQL function and then be called in SQL queries.

Getting started

Main classes

The two main classes are sqxx::connection, which represents a database connection, and sqxx::statement, which represents a SQL statement including binding of parameters, executing the statement, and accessing the results of the execution.

Common usage

Untested at the moment and subject to change if something turns out to be a bad idea.

// opening a database
sqxx::connection conn("example.db");

// simple statement execution
conn.exec("create table items (id integer, v integer)");
conn.exec("insert into items (id, value) values (1, 11), (2, 22), (3, 33)");

// getting results
sqxx::statement s1 = conn.exec("select * from items where id = 1");
std::cout << "id=" << s1.val<int>(0) << " value=" << s1.val<int>(1) << std::endl;

// iterating over multiple result rows
sqxx::statement s2 = conn.exec("select * from items where id = 1");
for (auto &r : s2) {
   std::cout << r.val<int>(1) << std::endl;
}

// Prepared statements
sqxx::statement s3 = conn.prepare("select value from items where id = ?");
s3.param(0).bind_int(2);
s3.run();
std::cout << "id=2 value=" << s3.val<int>(0) << std::endl;

//s3.reset();
 //s3.clear_bindings();
//s3.param(0) = 3;
//s3.run();
//int v = s3.col(0);
//std::cout << "id=3 value=" << v << std::endl;

Changed semantics compared to the C API

Parameter indexes in prepared statements start with zero (not one).

The sqlite3 C API uses parameter indexes starting with one, but this is inconsistent with for example column indexes (which start with zero). Additionally indexes starting with one are generally surprising and uncommon ind C/C++.

The index zero is used as an error value in in the C API, but in C++ we can use exceptions instead.

sqxx therefore uses zero-based indexing for parameters.

Everything is UTF-8

The C API usually provides several variants of its functions that can be used to access data in UTF-8, UTF-16 little endian or UTF-16 big endian. This complexity was omitted in this library and sqxx always uses the UTF-8 versions of functions and expects all strings to be encoded in UTF-8. Whenever there is a choice between several encodings in the C API, sqxx uses UTF-8 and assumes the corresponding data is encoded UTF-8.

Consistent naming for handler/callback functions

The sqlite3 API provides several functions that register different kinds of callback functions. Despite all of them registering a callback function for some event, they have quite different names in the C API, like sqlite3_commit_hook(), sqlite3_trace(), sqlite3_set_authorizer() or sqlite3_busy_handler(). sqxx doesn't directly follow these names, but uses the more consistent naming scheme set_..._handler() for all of them.

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