Moving Column to make it an inner class of Statement

- Column must not be used directly, only as a temporary Adapter of Statement::getColumn
- Adding an Object Oriented example in main.cpp
This commit is contained in:
Sébastien Rombauts 2012-04-02 19:00:24 +02:00
parent 68bf74e0a5
commit 00a8e0a642
6 changed files with 210 additions and 160 deletions

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@ -1,63 +0,0 @@
/**
* @file Column.cpp
* @brief A SQLite Column is a result field in a certain row.
*
* Copyright (c) 2012 Sebastien Rombauts (sebastien dot rombauts at gmail dot com)
*
* Distributed under the MIT License (MIT) (See accompanying file LICENSE.txt
* or copy at http://opensource.org/licenses/MIT)
*/
#include "Column.h"
#include "Database.h"
#include <iostream>
namespace SQLite
{
// Encapsulation of a Column in a Row of the result.
Column::Column(sqlite3* apSQLite, sqlite3_stmt* apStmt, int aIndex) throw() : // nothrow
mpSQLite(apSQLite),
mpStmt(apStmt),
mIndex(aIndex)
{
}
Column::~Column(void) throw() // nothrow
{
}
// Return the integer value of the column specified by its index starting at 0
int Column::getInt(void) const // throw(SQLite::Exception)
{
return sqlite3_column_int(mpStmt, mIndex);
}
// Return the 64bits integer value of the column specified by its index starting at 0
sqlite3_int64 Column::getInt64(void) const // throw(SQLite::Exception)
{
return sqlite3_column_int64(mpStmt, mIndex);
}
// Return the double value of the column specified by its index starting at 0
double Column::getDouble(void) const // throw(SQLite::Exception)
{
return sqlite3_column_double(mpStmt, mIndex);
}
// Return the text value (NULL terminated string) of the column specified by its index starting at 0
const char * Column::getText(void) const // throw(SQLite::Exception)
{
return (const char*)sqlite3_column_text(mpStmt, mIndex);
}
}; // namespace SQLite
// Standard std::ostream inserter
std::ostream& operator<<(std::ostream &stream, SQLite::Column const& column)
{
stream << column.getText();
return stream;
}

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@ -1,90 +0,0 @@
/**
* @file Column.h
* @brief A SQLite Column is a result field in a certain row.
*
* Copyright (c) 2012 Sebastien Rombauts (sebastien dot rombauts at gmail dot com)
*
* Distributed under the MIT License (MIT) (See accompanying file LICENSE.txt
* or copy at http://opensource.org/licenses/MIT)
*/
#pragma once
#include <sqlite3.h>
#include "Exception.h"
namespace SQLite
{
// Forward declaration
class Database;
/**
* @brief Encapsulation of a Column in a Row of the result.
*
* A Column is a particular field of SQLite data in the current row of result of the Statement.
*
* @warning A Column object must not be copied or memorized as it is only valid for a short time,
* only while the row from the Statement remains valid, that is only until next executeStep
*/
class Column
{
public:
/**
* @brief Compile and register the SQL query for the provided SQLite Database Connection
*/
explicit Column(sqlite3* apSQLite, sqlite3_stmt* apStmt, int aIndex) throw(); // nothrow
/// Basic destructor
virtual ~Column(void) throw(); // nothrow
/// Return the integer value of the column.
int getInt (void) const; // throw(SQLite::Exception);
// Return the 64bits integer value of the column.
sqlite3_int64 getInt64 (void) const; // throw(SQLite::Exception);
// Return the double (64bits float) value of the column.
double getDouble(void) const; // throw(SQLite::Exception);
// Return the text value (NULL terminated string) of the column.
const char* getText (void) const; // throw(SQLite::Exception);
/// Inline cast operator to int
inline operator const int() const
{
return getInt();
}
/// Inline cast operator to 64bits integer
inline operator const sqlite3_int64() const
{
return getInt64();
}
/// Inline cast operator to double
inline operator const double() const
{
return getDouble();
}
/// Inline cast operator to char*
inline operator const char*() const
{
return getText();
}
/// Inline cast operator to std::string
inline operator const std::string() const
{
return getText();
}
private:
// Column is copyable, but copy should not be used elsewhere than in return form getColumn
Column(void);
Column& operator=(const Column&);
private:
sqlite3* mpSQLite; //!< Pointer to SQLite Database Connection Handle
sqlite3_stmt* mpStmt; //!< Pointeur to SQLite Statement Object
int mIndex; //!< Index of the column in the row of result
};
}; // namespace SQLite
/// Standard std::ostream inserter
std::ostream& operator<<(std::ostream &stream, SQLite::Column const& column);

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@ -39,7 +39,7 @@ Database::~Database(void) throw() // nothrow
iStatement++)
{
// TODO (*iStatement)->Finalize(); ?
std::cout << "Unregistered statement: " << (*iStatement)->getQuery().c_str() << " !\n";
//std::cout << "Unregistered statement: " << (*iStatement)->getQuery().c_str() << " !\n";
}
int ret = sqlite3_close(mpSQLite);

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@ -118,7 +118,7 @@ bool Statement::executeStep(void) // throw(SQLite::Exception)
}
// Return a copy of the column data specified by its index starting at 0
Column Statement::getColumn(const int aIndex) const // throw(SQLite::Exception)
Statement::Column Statement::getColumn(const int aIndex) const // throw(SQLite::Exception)
{
if (false == mbOk)
{
@ -159,5 +159,55 @@ void Statement::check(const int aRet) const // throw(SQLite::Exception)
}
}
////////////////////////////////////////////////////////////////////////////////
// Implementation of the inner class Statement::Column
//
// Warning : you should never try to use directly a Column object, nor copying it;
// is is only an Adapter class designed to convert the result value
// of Statement::getColumn() to the data type you want
//
// Encapsulation of a Column in a Row of the result.
Statement::Column::Column(sqlite3* apSQLite, sqlite3_stmt* apStmt, int aIndex) throw() : // nothrow
mpSQLite(apSQLite),
mpStmt(apStmt),
mIndex(aIndex)
{
}
Statement::Column::~Column(void) throw() // nothrow
{
}
// Return the integer value of the column specified by its index starting at 0
int Statement::Column::getInt(void) const throw() // nothrow
{
return sqlite3_column_int(mpStmt, mIndex);
}
// Return the 64bits integer value of the column specified by its index starting at 0
sqlite3_int64 Statement::Column::getInt64(void) const throw() // nothrow
{
return sqlite3_column_int64(mpStmt, mIndex);
}
// Return the double value of the column specified by its index starting at 0
double Statement::Column::getDouble(void) const throw() // nothrow
{
return sqlite3_column_double(mpStmt, mIndex);
}
// Return the text value (NULL terminated string) of the column specified by its index starting at 0
const char * Statement::Column::getText(void) const throw() // nothrow
{
return (const char*)sqlite3_column_text(mpStmt, mIndex);
}
// Standard std::ostream inserter
std::ostream& operator<<(std::ostream &stream, const Statement::Column& column)
{
stream << column.getText();
return stream;
}
}; // namespace SQLite

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@ -11,7 +11,6 @@
#include <sqlite3.h>
#include "Exception.h"
#include "Column.h"
namespace SQLite
{
@ -27,6 +26,10 @@ class Database;
*/
class Statement
{
public:
// Forward declaration of the inner class "Column"
class Column;
public:
/**
* @brief Compile and register the SQL query for the provided SQLite Database Connection
@ -89,7 +92,6 @@ public:
*/
Column getColumn (const int aIndex) const; // throw(SQLite::Exception);
/**
* @brief Test if the column is NULL
*/
@ -129,6 +131,74 @@ public:
return mbDone;
}
public:
/**
* @brief Encapsulation of a Column in a Row of the result.
*
* A Column is a particular field of SQLite data in the current row of result of the Statement.
*
* @warning A Column object must not be copied or memorized as it is only valid for a short time,
* only while the row from the Statement remains valid, that is only until next executeStep
*/
class Column
{
/// Standard std::ostream inserter
friend std::ostream& operator<<(std::ostream &stream, const Column& column);
public:
/**
* @brief Compile and register the SQL query for the provided SQLite Database Connection
*/
explicit Column(sqlite3* apSQLite, sqlite3_stmt* apStmt, int aIndex) throw(); // nothrow
/// Basic destructor
virtual ~Column(void) throw(); // nothrow
/// Return the integer value of the column.
int getInt (void) const throw();
// Return the 64bits integer value of the column.
sqlite3_int64 getInt64 (void) const throw();
// Return the double (64bits float) value of the column.
double getDouble(void) const throw();
// Return the text value (NULL terminated string) of the column.
const char* getText (void) const throw();
/// Inline cast operator to int
inline operator const int() const
{
return getInt();
}
/// Inline cast operator to 64bits integer
inline operator const sqlite3_int64() const
{
return getInt64();
}
/// Inline cast operator to double
inline operator const double() const
{
return getDouble();
}
/// Inline cast operator to char*
inline operator const char*() const
{
return getText();
}
/// Inline cast operator to std::string
inline operator const std::string() const
{
return getText();
}
private:
// Column is copyable, but copy should not be used elsewhere than in return form getColumn
Column(void);
Column& operator=(const Column&);
private:
sqlite3* mpSQLite; //!< Pointer to SQLite Database Connection Handle
sqlite3_stmt* mpStmt; //!< Pointeur to SQLite Statement Object
int mIndex; //!< Index of the column in the row of result
};
private:
// Statement must not be copyable
Statement(void);

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@ -1,8 +1,61 @@
/**
* @file main.cpp
* @brief Two short examples in a row.
*
* Demonstrate how-to use the SQLite++ wrapper
*
* Copyright (c) 2012 Sebastien Rombauts (sebastien dot rombauts at gmail dot com)
*
* Distributed under the MIT License (MIT) (See accompanying file LICENSE.txt
* or copy at http://opensource.org/licenses/MIT)
*/
#include <iostream>
#include "../SQLiteC++/SQLiteC++.h"
#include "../SQLiteC++/Database.h"
#include "../SQLiteC++/Statement.h"
/// Object Oriented Basic example
class Example
{
public:
Example(void) :
mDb("example.db3"), // Open a database file
mQuery(mDb, "SELECT * FROM test WHERE size > ?") // Compile a SQL query, containing one parameter (index 1)
{
}
virtual ~Example(void)
{
}
// List the rows where the "size" column is greater than the provided aParamValue
void ListGreaterThan (const int aParamValue)
{
std::cout << "ListGreaterThan (" << aParamValue << ")\n";
// Bind the integer value provided to the first parameter of the SQL query
mQuery.bind(1, aParamValue);
// Loop to execute the query step by step, to get one a row of results at a time
while (mQuery.executeStep())
{
std::cout << "row : (" << mQuery.getColumn(0) << ", " << mQuery.getColumn(1) << ", " << mQuery.getColumn(2) << ")\n";
}
// Reset the query to be able to use it again later
mQuery.reset();
}
private:
SQLite::Database mDb;
SQLite::Statement mQuery;
};
int main (void)
{
// Basic example (1/2) :
try
{
// Open a database file
@ -10,19 +63,32 @@ int main (void)
std::cout << "SQLite database file '" << db.getFilename().c_str() << "' opened successfully\n";
// Compile a SQL query, containing one parameter (index 1)
SQLite::Statement query(db, "SELECT * FROM test WHERE size>?");
SQLite::Statement query(db, "SELECT * FROM test WHERE size > ?");
std::cout << "SQLite statement '" << query.getQuery().c_str() << "' compiled (" << query.getColumnCount () << " columns in the result)\n";
// Bind an integer value "6" to the first parameter of the SQL query
// Bind the integer value 6 to the first parameter of the SQL query
query.bind(1, 6);
// Loop to execute the query step by step, to get one a row of results at a time
while (query.executeStep())
{
// Demonstrate how to get some typed column value
int id = query.getColumn(0); // = query.getColumn(0).getInt()
//const char* pvalue = query.getColumn(1); // = query.getColumn(1).getText()
std::string value = query.getColumn(1); // = query.getColumn(1).getText()
int size = query.getColumn(2); // = query.getColumn(2).getInt()
std::cout << "row : (" << id << ", " << value << ", " << size << ")\n";
}
// Reset the query to use it again
query.reset();
std::cout << "SQLite statement '" << query.getQuery().c_str() << "' reseted (" << query.getColumnCount () << " columns in the result)\n";
// Bind the string value "6" to the first parameter of the SQL query
query.bind(1, "6");
while (query.executeStep())
{
// Demonstrate that inserting column value in a std:ostream is natural
std::cout << "row : (" << query.getColumn(0) << ", " << query.getColumn(1) << ", " << query.getColumn(2) << ")\n";
}
}
@ -31,5 +97,22 @@ int main (void)
std::cout << "SQLite exception: " << e.what() << std::endl;
}
////////////////////////////////////////////////////////////////////////////
// Object Oriented Basic example (2/2) :
try
{
// Open the database and compile the query
Example example;
// Demonstrate the way to use the same query with different parameter values
example.ListGreaterThan(8);
example.ListGreaterThan(6);
example.ListGreaterThan(2);
}
catch (std::exception& e)
{
std::cout << "SQLite exception: " << e.what() << std::endl;
}
return 0;
}