SOCI - The C++ Database Access Library

SQLite3 Backend Reference

Prerequisites

Supported Versions

The SOCI SQLite3 backend is supported for use with SQLite3 >= 3.1

Tested Platforms

Required Client Libraries

The SOCI SQLite3 backend requires SQLite3's libsqlite3 client library.

Connecting to the Database

To establish a connection to the SQLite3 database, create a Session object using the SQLite3 backend factory together with the database file name:

session sql(sqlite3, "database_filename");

The only option for the connection string is the name of the file to use as a database.

Once you have created a session object as shown above, you can use it to access the database, for example:

int count;
sql << "select count(*) from invoices", into(count);

(See the SOCI basics and exchanging data documentation for general information on using the session class.)

SOCI Feature Support

Dynamic Binding

The SQLite3 backend supports the use of the SOCI row class, which facilitates retrieval of data whose type is not known at compile time.

When calling row::get<T>(), the type you should pass as T depends upon the underlying database type.

For the SQLite3 backend, this type mapping is complicated by the fact the SQLite3 does not enforce types *, and makes no attempt to validate the type names used in table creation or alteration statements. SQLite3 will return the type as a string, SOCI will recognize the following strings and match them the corresponding SOCI types:

* There is one case where SQLite3 enforces type. If a column is declared as "integer primary key", then SQLite3 uses that as an alias to the internal ROWID column that exists for every table. Only integers are allowed in this column.

(See the dynamic resultset binding documentation for general information on using the row class.)

Binding by Name

In addition to binding by position, the SQLite3 backend supports binding by name, via an overload of the use() function:

int id = 7;
sql << "select name from person where id = :id", use(id, "id")

The backend also supports the SQLite3 native numbered syntax, "one or more literals can be replace by a parameter "?" or ":AAA" or "@AAA" or "$VVV" where AAA is an alphanumeric identifier and VVV is a variable name according to the syntax rules of the TCL programming language." [1]:

int i = 7;
int j = 8;
sql << "insert into t(x, y) values(?, ?)", use(i), use(j);

Bulk Operations

The SQLite3 backend has full support for SOCI's bulk operations interface. However, this support is emulated and is not native.

Transactions

Transactions are also fully supported by the SQLite3 backend.

BLOB Data Type

The SQLite3 backend supports working with data stored in columns of type Blob, via SOCI's blob class. Because of SQLite3 general typelessness the column does not have to be declared any particular type.

RowID Data Type

In SQLite3 RowID is an integer. "Each entry in an SQLite table has a unique integer key called the "rowid". The rowid is always available as an undeclared column named ROWID, OID, or _ROWID_. If the table has a column of type INTEGER PRIMARY KEY then that column is another an alias for the rowid."[2]

Nested Statements

Nested statements are not supported by SQLite3 backend.

Stored Procedures

Stored procedures are not supported by SQLite3 backend

Acessing the native database API

SOCI provides access to underlying datbabase APIs via several get_backend() functions, as described in the beyond SOCI documentation.

The SQLite3 backend provides the following concrete classes for navite API access:

Backend-specific extensions

SQLite3 result code support

SQLite3 result code is provided via the backend specific sqlite3_soci_error class. Catching the backend specific error yields the value of SQLite3 result code via the result() method.

Configuration options

None

Copyright © 2004-2006 Maciej Sobczak, Stephen Hutton, David Courtney