CoreSQLite3 is sqlite3 library for iOS and Mac OSX platforms. It provides intuitive, Core Foundation based API for accessing and manipulating sqlite3 databases.

Toll-free bridging between Core Foundation and Objective-C Foundation allows CoreSQLite3 framework to be used directly from Objective-C code.

The framework includes amalgamation version of sqlite3 library. You can use this version of sqlite3 or system provided sqlite3.dylib on iOS and Mac OSX.

You may want to use included sqlite3-amalgamation version of the library because of the following reasons:

• it provides the latest version of sqlite3 library
• includes FTS3 (full text search) extension
• includes R*Tree extension for fast range and geo-spatial queries

Additionally CoreSQLite3 allows to register the following functions:

• math extension

  • sin(radians)
  • cos(radians)
  • deg2rad(degrees)
  • rad2deg(radians)
  • pi()

• logic extension

  • if(condition, value_if_true, value_if_false) -> null if condition is null or value_if_false when condition equals to zero, value_if_true otherwise

• crypto extension

  • md5(value) -> null if value is null, md5 hash string otherwise
  • sha1(value) -> null if value is null, md5 hash string otherwise

• spatial extension

  • lat_lng_dist_in_km(lat_1, long_2, lat_2, long_2) -> float
  • lat_lng_dist_in_mi(lat_1, long_2, lat_2, long_2) -> float

In order to register one or more of the functions above call the following function(s) on open connection:

• SQLite3ExtRegisterAllFunctions - to register all above functions
• SQLite3ExtMathRegisterAllFunctions - to register all math functions
• SQLite3ExtLogicRegisterAllFunctions - to register all math functions
• SQLite3ExtCryptoRegisterAllFunctions - to register all math functions
• SQLite3ExtSpatialRegisterAllFunctions - to register all math functions

You can also register and unregister individual functions by calling:

• SQLite3ExtMathRegisterSinFunction
• SQLite3ExtLogicUnregisterIfFunction

SQLite3ConnectionCreate

SQLite3ConnectionClose SQLite3ConnectionRelease

SQLite3StatementCreate SQLite3StatementFinalize

SQLite3StatementBindValue SQLite3StatementClearBindings

Return value kSQLite3StatusOK on success, kSQLite3StatusError otherwise.

SQLite3 supports the following format for parameter bindings:

• ? or ?1 - index based bindings
• :name, @name, $name - name based bindings

Example queries:

• select * from users where username = ? and password = ?
• select * from users where username = ?1 and password = ?2 and (?1 <> ?2)
• select * from users where username = :username and password = :password

Please note when binding values, the binding name should include ?, : prefix. Example:

SQLite3StatementBindStringWithName(statement, CFSTR(':username'), CFSTR('mirek'));

CoreSQLite3 provides the following function to simplify working with serialised columns (structured data stored in single value):

• SQLite3StatementBindPropertyList - bind property list value, the value is serialised with the specified encoding
• SQLite3StatementCreatePropertyListWithColumn or SQLite3StatementCreatePropertyListWithColumnName - get property list value by deserializing row data for specified column

Serialised value can be one of:

• CFData, CFString, CFArray, CFDictionary, CFDate, CFBoolean and CFNumber

or one of their counterparts in Objective-C Foundation:

• NSData, NSString, NSArray, NSDictionary, NSDate and NSNumber

The type of column for serialised data should be text (for XML based serialisation) or blob (for binary based serialisation).

Example usage:

NSDictionary *preferences = [NSDictionary dictionaryWithObjectsAndKeys:
                             [NSArray arrayWithObjects: @"English", @"German"], @"languages",
                             @"English", @"preferred",
                             nil];

SQLite3StatementRef statement = SQLite3StatementCreate(connection, @"update users set data = :preferences where id = :id");
SQLite3StatementBindIntegerWithName(statement, @"id", 1);
SQLite3StatementBindPropertyList(statement, preferences);
SQlite3StatementExecute(statement);
SQLite3StatementClearBindings(statement);
SQLite3StatementReset(statement);
SQLite3StatementFinalize(statement);
SQLite3StatementRelease(statement);

To retrieve serialised object graph back you can use SQLite3StatementCreatePropertyListWithColumn or connection's function:

id preferences = SQLite3ConnectionCreatePropertyListWithQuery(connection, @"select data from users where id = 1");

Schema migration pattern has been included as an extra functionality built on top of the core functions.

Pattern of schema migrations is similar to Ruby on Rails one.

/migrations/20100209-111000-init.sql
/migrations/20100209-111000.undo.sql (optional)
/migrations/20100209-111000-create-users.sql
/migrations/20100209-111000.undo.sql (optional)

Typical usage:

CFErrorRef error = NULL;

// As an example, let's create in-memory database
SQLite3ConnectionRef connection = SQLite3ConnectionCreate(CFSTR(":memory:"), 0);

// SQL queries can be executed directly on the connection
SQLite3ConnectionExecute(connection, CFSTR("create table users(id integer primary key, name varchar, surname varchar)"));
if ((error = SQLite3ConnectionCreateError(connection))) {
  CFShow(error);
  CFRelease(error);
  exit(-1);
}

// Simple binding
{
  SQLite3StatementRef statement = SQLite3StatementCreate(connection, CFSTR("insert into users(name, surname) values(?, ?)"));
  SQLite3StatementBindString(statement, CFSTR("Mirek"));
  SQLite3StatementBindString(statement, CFSTR("Rusin"));
  SQLite3StatementExecute(statement);
  if ((error = SQLite3ConnectionCreateError(connection))) {
    CFShow(error);
    CFRelease(error);
    exit(-1);
  }
  SQLite3StatementRelease(statement);
}

// We can use toll-free bridging for Core Foundation types, so it's easy to use the library from Objective-C
{
  NSArray values = [NSArray arrayWithObjects: @"Mirek", @"Rusin", nil];
  SQLite3StatementRef statement = SQLite3StatementCreate(connection, CFSTR("insert into users(name, surname) values(?, ?)"));
  SQLite3StatementBindArray(statement, (CFArrayRef)values);
  SQLite3StatementExecute(statement);
  if ((error = SQLite3ConnectionCreateError(connection))) {
    CFShow(error);
    CFRelease(error);
    exit(-1);
  }
  SQLite3StatementRelease(statement);
}

// Selecting is easy
{
  SQLite3StatementRef statement = SQLite3StatementCreate(connection, CFSTR("select name, surname from users"));
  while (SQLite3StatementStep(statement) == SQLITE_ROW) {
    CFStringRef name = SQLite3StatementGetString(statement, 0);
    CFStringRef surname = SQLite3StatementGetString(statement, 1);
    NSLog(@"name: %@, surname: %@", name, surname);
    CFRelease(name);
    CFRelease(surname);
  }
  if ((error = SQLite3ConnectionCreateError(connection))) {
    CFShow(error);
    CFRelease(error);
    exit(-1);
  }
  SQLite3StatementRelease(statement);
}

// Images are supported out-of-the-box
{

}

SQLite3ConnectionRelease(connection);