# Poco::Data::SQLite

# class Utility

Library: Data/SQLite
Package: SQLite
Header: Poco/Data/SQLite/Utility.h

## Description

Various utility functions for SQLite.

## Member Summary

Member Functions: dbHandle, fileToMemory, getColumnType, getThreadMode, isThreadSafe, lastError, memoryToFile, registerUpdateHandler, setThreadMode, throwException

## Nested Classes

### class SQLiteMutex

## Types

### CommitCallbackType

typedef int (* CommitCallbackType)(void *);

Commit callback function type.

### RollbackCallbackType

typedef void (* RollbackCallbackType)(void *);

Rollback callback function type.

### TypeMap

typedef std::map < std::string, MetaColumn::ColumnDataType > TypeMap;

### UpdateCallbackType

typedef void (* UpdateCallbackType)(void *, int, const char *, const char *, Poco::Int64);

Update callback function type.

## Enumerations

### TransactionType

DEFERRED

EXCLUSIVE

IMMEDIATE

## Constructors

## Member Functions

### dbHandle

static sqlite3 * dbHandle(
const Session & session
);

Returns native DB handle.

### fileToMemory

static bool fileToMemory(
sqlite3 * pInMemory,
const std::string & fileName
);

Loads the contents of a database file on disk into an opened database in memory.

Returns true if succesful.

### fileToMemory

static bool fileToMemory(
const Session & session,
const std::string & fileName
);

Loads the contents of a database file on disk into an opened database in memory.

Returns true if succesful.

### getColumnType

static MetaColumn::ColumnDataType getColumnType(
sqlite3_stmt * pStmt,
std::size_t pos
);

Returns column data type.

### getThreadMode

static int getThreadMode();

Returns the thread mode.

### isThreadSafe

static bool isThreadSafe();

Returns true if SQLite was compiled in multi-thread or serialized mode. See http://www.sqlite.org/c3ref/threadsafe.html for details.

Returns true if succesful

### lastError

static std::string lastError(
sqlite3 * pDB
);

Retreives the last error code from sqlite and converts it to a string.

### lastError

static std::string lastError(
const Session & session
);

Retreives the last error code from sqlite and converts it to a string.

### memoryToFile

static bool memoryToFile(
const std::string & fileName,
sqlite3 * pInMemory
);

Saves the contents of an opened database in memory to the database on disk.

Returns true if succesful.

### memoryToFile

static bool memoryToFile(
const std::string & fileName,
const Session & session
);

Saves the contents of an opened database in memory to the database on disk.

Returns true if succesful.

### registerUpdateHandler

template < typename T, typename CBT > static bool registerUpdateHandler(
sqlite3 * pDB,
CBT callbackFn,
T * pParam
);

Registers the callback for (1)(insert, delete, update), (2)(commit) or or (3)(rollback) events. Only one function per group can be registered at a time. Registration is not thread-safe. Storage pointed to by pParam must remain valid as long as registration is active. Registering with callbackFn set to zero disables notifications.

See http://www.sqlite.org/c3ref/update_hook.html and http://www.sqlite.org/c3ref/commit_hook.html for details.

### registerUpdateHandler

template < typename T, typename CBT > static bool registerUpdateHandler(
const Session & session,
CBT callbackFn,
T * pParam
);

Registers the callback by calling registerUpdateHandler(sqlite3*, CBT, T*).

### setThreadMode

static bool setThreadMode(
int mode
);

Sets the threading mode to single, multi or serialized. See http://www.sqlite.org/threadsafe.html for details.

Returns true if succesful

### throwException

static void throwException(
sqlite3 * pDB,
int rc,
const std::string & addErrMsg = std::string ()
);

Throws for an error code the appropriate exception

## Variables

### OPERATION_DELETE

static const int OPERATION_DELETE;

### OPERATION_INSERT

static const int OPERATION_INSERT;

### OPERATION_UPDATE

static const int OPERATION_UPDATE;

### SQLITE_DATETIME_FRAC_FORMAT

static const std::string SQLITE_DATETIME_FRAC_FORMAT;

### SQLITE_DATE_FORMAT

static const std::string SQLITE_DATE_FORMAT;

### SQLITE_TIME_FORMAT

static const std::string SQLITE_TIME_FORMAT;

### THREAD_MODE_MULTI

static const int THREAD_MODE_MULTI;

### THREAD_MODE_SERIAL

static const int THREAD_MODE_SERIAL;

### THREAD_MODE_SINGLE

static const int THREAD_MODE_SINGLE;

### TRANSACTION_TYPE_PROPERTY_KEY

static const std::string TRANSACTION_TYPE_PROPERTY_KEY;