wxSQLite3  4.1.1
Public Member Functions | Protected Attributes | Friends | List of all members
wxSQLite3NamedCollection Class Reference

Represents a named collection. More...

#include <wxsqlite3.h>

Inheritance diagram for wxSQLite3NamedCollection:
wxSQLite3IntegerCollection wxSQLite3StringCollection

Public Member Functions

 wxSQLite3NamedCollection ()
 Constructor. More...
 
 wxSQLite3NamedCollection (const wxSQLite3NamedCollection &collection)
 Copy constructor. More...
 
wxSQLite3NamedCollectionoperator= (const wxSQLite3NamedCollection &collection)
 Assignment constructor. More...
 
 wxSQLite3NamedCollection (const wxString &collectionName, void *collectionData)
 Constructor (internal use only) More...
 
virtual ~wxSQLite3NamedCollection ()
 Destructor. More...
 
const wxString & GetName () const
 Get the name of the collection. More...
 

Protected Attributes

wxString m_name
 Name of the collection. More...
 
void * m_data
 Reference to the actual array of values representing the collection. More...
 

Friends

class wxSQLite3Database
 

Detailed Description

Represents a named collection.

A named collection is designed to facilitate using an array of integers or strings as the right-hand side of an IN operator. So instead of doing a prepared statement like this:

SELECT * FROM table WHERE x IN (?,?,?,...,?);

And then binding individual integers to each of ? slots, an application can create a named collection object (named "ex1" in the following example), prepare a statement like this:

SELECT * FROM table WHERE x IN ex1;

Then bind an array of integer or string values to the ex1 object to run the statement.

USAGE:

One or more named collection objects can be created as follows:

 wxSQLite3IntegerCollection p1, p2, p3;
 p1 = db.CreateIntegerCollection("ex1");
 p2 = db.CreateIntegerCollection("ex2");
 p3 = db.CreateIntegerCollection("ex3");

Each call to CreateIntegerCollection generates a new virtual table module and a singleton of that virtual table module in the TEMP database. Both the module and the virtual table instance use the name given by the second parameter. The virtual tables can then be used in prepared statements:

 SELECT * FROM t1, t2, t3
  WHERE t1.x IN ex1
    AND t2.y IN ex2
    AND t3.z IN ex3;

Each integer array is initially empty. New arrays can be bound to an integer array as follows:

int a1[] = { 1, 2, 3, 4 };
int a2[] = { 5, 6, 7, 8, 9, 10, 11 };
wxArrayInt a3;
// Fill a3
p1.Bind(4, a1);
p2.Bind(7, a2);
p3.Bind(a3);

A single named collection object can be rebound multiple times. But do not attempt to change the bindings of a named collection while it is in the middle of a query.

The array that holds the integer or string values is automatically allocated by the Bind method.

The named collection object is automatically destroyed when its corresponding virtual table is dropped. Since the virtual tables are created in the TEMP database, they are automatically dropped when the database connection closes so the application does not normally need to take any special action to free the named collection objects.

Constructor & Destructor Documentation

◆ wxSQLite3NamedCollection() [1/3]

wxSQLite3NamedCollection::wxSQLite3NamedCollection ( )

Constructor.

◆ wxSQLite3NamedCollection() [2/3]

wxSQLite3NamedCollection::wxSQLite3NamedCollection ( const wxSQLite3NamedCollection collection)

Copy constructor.

◆ wxSQLite3NamedCollection() [3/3]

wxSQLite3NamedCollection::wxSQLite3NamedCollection ( const wxString &  collectionName,
void *  collectionData 
)

Constructor (internal use only)

◆ ~wxSQLite3NamedCollection()

wxSQLite3NamedCollection::~wxSQLite3NamedCollection ( )
virtual

Destructor.

Member Function Documentation

◆ GetName()

const wxString& wxSQLite3NamedCollection::GetName ( ) const
inline

Get the name of the collection.

Returns
the name of the collection

◆ operator=()

wxSQLite3NamedCollection & wxSQLite3NamedCollection::operator= ( const wxSQLite3NamedCollection collection)

Assignment constructor.

Friends And Related Function Documentation

◆ wxSQLite3Database

friend class wxSQLite3Database
friend

Member Data Documentation

◆ m_data

void* wxSQLite3NamedCollection::m_data
protected

Reference to the actual array of values representing the collection.

◆ m_name

wxString wxSQLite3NamedCollection::m_name
protected

Name of the collection.


The documentation for this class was generated from the following files: