Database

Overview

A Database object is a wrapper around a raw sqlite3* pointer. The pointer is stored in a boost::shared_ptr, making Databases instances flyweight and copyable. When the last Database object owning a given sqlite3* pointer is deleted, the connection is closed.

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Constructors

Name	Description
Database()	Constructs an empty database object.
Database(const char* filename)	Constructs a new database / opens an existing database.

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Accessors

Name	Description
bool connected() const	Answers whether the given instance is connected to a real database.
Statement make(const char* query) const	Prepares a statement from the given query.
sqlite3* raw_data() const	Access the underlying raw sqlite3* pointer.

Notes:

• db.connected() is equivalent to db.raw_data() != 0.
• The raw_data pointer is not meant to be stored and used outside of the Database instance, as its lifetime is managed via reference counting in the instance itself.

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Mutators

Name	Description
void connect(const char* filename)	Constructs a new database / opens an existing database.
void disconnect()	Disconnects the instance from its current database if any.

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Execution

Name	Description
Rows exec(const char* q) const	Execute a query -> rows
Rows exec(const char* q, const Parameters& ps) const	Execute a query -> rows
void exec(const char* q, const RowCallback& cb) const	Execute a query, callback on each row.
void exec(const char* q, const RowCallback& cb, const Parameters& ps) const	Execute a query, callback on each row.
RowRange result(const char* q) const	Execute a query -> row range.
RowRange result(const char* q, const Parameters& ps) const	Execute a query -> row range.

Notes:

• Rows store the whole query result in memory, while RowRange allows you to iterate on the results one database row at a time.
• Use the provided saw_foreach macro to iterate on a RowRange:

saw_foreach (const Row& r, db.result("select * from clients"))
{
  // do something with r
}

• Variants with a Parameters argument will perform parameter substitution.