SQLite wrapper

Posted 2022-09-05 blogpro

SQLiteWrapper is a C++ wrapper for SQLite.

There are some test programs that demonstrate how the SQLite Wrapper classes are used.

The implementation file

SQLiteWrapper.cpp

/*

SQLiteWrapper.cpp

 

Copyright (C) 2004 René Nyffenegger

 

This source code is provided ‘as-is‘, without any express or implied

warranty. In no event will the author be held liable for any damages

arising from the use of this software.

 

Permission is granted to anyone to use this software for any purpose,

including commercial applications, and to alter it and redistribute it

freely, subject to the following restrictions:

 

1. The origin of this source code must not be misrepresented; you must not

claim that you wrote the original source code. If you use this source code

in a product, an acknowledgment in the product documentation would be

appreciated but is not required.

 

2. Altered source versions must be plainly marked as such, and must not be

misrepresented as being the original source code.

 

3. This notice may not be removed or altered from any source distribution.

 

René Nyffenegger [e-mail]

 

*/

 

#include "SQLiteWrapper.h"

// TODO: raus

#include <windows.h>

 

SQLiteWrapper::SQLiteWrapper() : db_(0)

 

bool SQLiteWrapper::Open(std::string const& db_file)

if (sqlite3_open(db_file.c_str(), &db_) != SQLITE_OK)

return false;

return true;

 

bool SQLiteWrapper::SelectStmt(std::string const& stmt, ResultTable& res)

char *errmsg;

int ret;

 

res.reset();

 

ret = sqlite3_exec(db_, stmt.c_str(), SelectCallback, static_cast<void*> (&res), &errmsg);

 

if (ret != SQLITE_OK)

return false;

return true;

// if (ret != SQLITE_OK)

// std::cout << stmt << " [" << errmsg << "]" << std::endl;

//

 

// TODO parameter p_col_names

int SQLiteWrapper::SelectCallback(void *p_data, int num_fields, char **p_fields, char** p_col_names)

ResultTable* res = reinterpret_cast<ResultTable*>(p_data);

 

ResultRecord record;

 

#ifdef SQLITE_WRAPPER_REPORT_COLUMN_NAMES

// Hubert Castelain: column names in the first row of res if res is empty

 

if(res->records_.size()==0)

ResultRecord col_names;

 

for(int i=0; i < num_fields; i++)

if(p_fields[i]) col_names.fields_.push_back (p_col_names[i]);

else

col_names.fields_.push_back("(null)"); // or what else ?

res->records_.push_back(col_names);

#endif

 

for(int i=0; i < num_fields; i++)

// Hubert Castelain: special treatment if null

if (p_fields[i]) record.fields_.push_back(p_fields[i]);

else record.fields_.push_back("<null>");

 

res->records_.push_back(record);

 

return 0;

 

SQLiteStatement* SQLiteWrapper::Statement(std::string const& statement)

SQLiteStatement* stmt;

try

stmt = new SQLiteStatement(statement, db_);

return stmt;

catch (const char* e)

return 0;

 

SQLiteStatement::SQLiteStatement(std::string const& statement, sqlite3* db)

if ( sqlite3_prepare(

db,

statement.c_str(), // stmt

-1, // If than zero, then stmt is read up to the first nul terminator

&stmt_,

0 // Pointer to unused portion of stmt

)

!= SQLITE_OK)

throw sqlite3_errmsg(db);

 

if (!stmt_)

throw "stmt_ is 0";

 

SQLiteStatement::~SQLiteStatement()

// Hubert Castelain 28/8/2005

// Prevent the database remaining locked after some statement.

// syntax: int sqlite3_finalize(sqlite3_stmt *pStmt);

if(stmt_) sqlite3_finalize(stmt_);

 

SQLiteStatement::SQLiteStatement() :

stmt_ (0)

 

bool SQLiteStatement::Bind(int pos_zero_indexed, std::string const& value)

if (sqlite3_bind_text (

stmt_,

pos_zero_indexed+1, // Index of wildcard

value.c_str(),

value.length(), // length of text

SQLITE_TRANSIENT // SQLITE_TRANSIENT: SQLite makes its own copy

)

!= SQLITE_OK)

return false;

return true;

 

bool SQLiteStatement::Bind(int pos_zero_indexed, double value)

if (sqlite3_bind_double(

stmt_,

pos_zero_indexed+1, // Index of wildcard

value

)

!= SQLITE_OK)

return false;

return true;

 

bool SQLiteStatement::Bind(int pos_zero_indexed, int value)

if (sqlite3_bind_int(

stmt_,

pos_zero_indexed+1, // Index of wildcard

value

)

!= SQLITE_OK)

return false;

return true;

 

bool SQLiteStatement::BindNull(int pos_zero_indexed)

if (sqlite3_bind_null(

stmt_,

pos_zero_indexed+1 // Index of wildcard

)

!= SQLITE_OK)

return false;

return true;

 

bool SQLiteStatement::Execute()

int rc = sqlite3_step(stmt_);

if (rc == SQLITE_BUSY)

::MessageBox(0, "SQLITE_BUSY", 0, 0);

return false;

if (rc == SQLITE_ERROR)

::MessageBox(0, "SQLITE_ERROR", 0, 0);

return false;

if (rc == SQLITE_MISUSE)

::MessageBox(0, "SQLITE_ERROR", 0, 0);

return false;

if (rc != SQLITE_DONE)

//sqlite3_reset(stmt_);

return false;

sqlite3_reset(stmt_);

return true;

 

SQLiteStatement::dataType SQLiteStatement::DataType(int pos_zero_indexed)

return dataType(sqlite3_column_type(stmt_, pos_zero_indexed));

 

int SQLiteStatement::ValueInt(int pos_zero_indexed)

return sqlite3_column_int(stmt_, pos_zero_indexed);

 

std::string SQLiteStatement::ValueString(int pos_zero_indexed)

return std::string(reinterpret_cast<const char*>(sqlite3_column_text(stmt_, pos_zero_indexed)));

 

bool SQLiteStatement::RestartSelect()

sqlite3_reset(stmt_);

return true;

 

bool SQLiteStatement::Reset()

int rc = sqlite3_step(stmt_);

 

sqlite3_reset(stmt_);

 

if (rc == SQLITE_ROW) return true;

return false;

 

bool SQLiteStatement::NextRow()

int rc = sqlite3_step(stmt_);

 

if (rc == SQLITE_ROW )

return true;

if (rc == SQLITE_DONE )

sqlite3_reset(stmt_);

return false;

else if (rc == SQLITE_MISUSE)

::MessageBox(0, "SQLiteStatement::NextRow SQLITE_MISUSE", 0, 0);

else if (rc == SQLITE_BUSY )

::MessageBox(0, "SQLiteStatement::NextRow SQLITE_BUSY", 0, 0);

else if (rc == SQLITE_ERROR )

::MessageBox(0, "SQLiteStatement::NextRow SQLITE_ERROR", 0, 0);

return false;

 

bool SQLiteWrapper::DirectStatement(std::string const& stmt)

char *errmsg;

int ret;

 

ret = sqlite3_exec(db_, stmt.c_str(), 0, 0, &errmsg);

 

if(ret != SQLITE_OK)

return false;

return true;

 

//if(ret != SQLITE_OK)

// std::cout << stmt << " [" << errmsg << "]" << std::endl;

//

 

std::string SQLiteWrapper::LastError()

return sqlite3_errmsg(db_);

 

bool SQLiteWrapper::Begin()

return DirectStatement("begin");

 

bool SQLiteWrapper::Commit()

return DirectStatement("commit");

 

bool SQLiteWrapper::Rollback()

return DirectStatement("rollback");

The header file

SQLiteWrapper.h

/*

SQLiteWrapper.h

 

Copyright (C) 2004 René Nyffenegger

 

This source code is provided ‘as-is‘, without any express or implied

warranty. In no event will the author be held liable for any damages

arising from the use of this software.

 

Permission is granted to anyone to use this software for any purpose,

including commercial applications, and to alter it and redistribute it

freely, subject to the following restrictions:

 

1. The origin of this source code must not be misrepresented; you must not

claim that you wrote the original source code. If you use this source code

in a product, an acknowledgment in the product documentation would be

appreciated but is not required.

 

2. Altered source versions must be plainly marked as such, and must not be

misrepresented as being the original source code.

 

3. This notice may not be removed or altered from any source distribution.

 

René Nyffenegger [e-mail]

*/

 

#ifndef SQLITE_WRAPPER_H__

#define SQLITE_WRAPPER_H__

 

#include <string>

#include <vector>

 

#include "sqlite3.h"

 

class SQLiteStatement

private:

// SQLiteStatement‘s ctor only to be called by SQLiteWrapper

friend class SQLiteWrapper;

SQLiteStatement(std::string const& statement, sqlite3* db);

 

public:

SQLiteStatement();

 

enum dataType

INT = SQLITE_INTEGER,

FLT = SQLITE_FLOAT ,

TXT = SQLITE_TEXT ,

BLB = SQLITE_BLOB ,

NUL = SQLITE_NULL ,

;

 

dataType DataType(int pos_zero_indexed);

 

int ValueInt (int pos_zero_indexed);

std::string ValueString(int pos_zero_indexed);

 

// SQLiteStatement(const SQLiteStatement&);

~SQLiteStatement();

 

//SQLiteStatement& operator=(SQLiteStatement const&);

 

bool Bind (int pos_zero_indexed, std::string const& value);

bool Bind (int pos_zero_indexed, double value);

bool Bind (int pos_zero_indexed, int value);

bool BindNull(int pos_zero_indexed);

 

bool Execute();

 

bool NextRow();

 

/* Call Reset if not depending on the NextRow cleaning up.

For example for select count(*) statements*/

bool Reset();

 

bool RestartSelect();

 

private:

//void DecreaseRefCounter();

 

//int* ref_counter_; // not yet used...

sqlite3_stmt* stmt_;

;

 

class SQLiteWrapper

public:

SQLiteWrapper();

 

bool Open(std::string const& db_file);

 

class ResultRecord

public:

std::vector<std::string> fields_;

;

 

class ResultTable

friend class SQLiteWrapper;

public:

ResultTable() : ptr_cur_record_(0)

 

std::vector<ResultRecord> records_;

 

ResultRecord* next()

if (ptr_cur_record_ < records_.size())

return &(records_[ptr_cur_record_++]);

return 0;

 

private:

void reset()

records_.clear();

ptr_cur_record_=0;

 

private:

unsigned int ptr_cur_record_;

;

 

bool SelectStmt (std::string const& stmt, ResultTable& res);

bool DirectStatement (std::string const& stmt);

SQLiteStatement* Statement(std::string const& stmt);

 

std::string LastError();

 

// Transaction related

bool Begin ();

bool Commit ();

bool Rollback();

 

private:

 

static int SelectCallback(void *p_data, int num_fields, char **p_fields, char **p_col_names);

 

sqlite3* db_;

;

 

#endif

Test cases

Test 1: creates a database and a table.

Test 2: inserts a record into the table without binding the value parameters.

Test 3: inserts two records into the table with binding the value parameters.

Test 4: selects * from the table and returns the selected values to the console.

Links

Joel on software reader is an application I wrote that uses this wrapper.

 

 

 

 

本地测试

/* SQLiteWrapper sqlite;

if (sqlite.Open("SQLiteWrapper.db"))

MessageBox(0,"成功打开数据库","提示",MB_ICONEXCLAMATION|MB_OKCANCEL );

else

MessageBox(0,"打开或创建数据库失败","提示",MB_ICONEXCLAMATION|MB_OKCANCEL );

 

if(sqlite.DirectStatement("create table File_list(id text,F_name text,Ex_name text,Path_name text,F_size text,C_time text,X_time text,F_time text,F_Con BLOB );"))

MessageBox(0,"创建File_list成功","提示",MB_ICONEXCLAMATION|MB_OKCANCEL );

else

MessageBox(0,"创建File_list失败","提示",MB_ICONEXCLAMATION|MB_OKCANCEL );

 

if(sqlite.DirectStatement("insert into File_list values(‘1‘,‘2‘,‘中国‘,‘4‘,‘English‘,‘6‘,‘7‘,‘8‘,‘9‘)"))

 

MessageBox(0,"插入成功","提示",MB_ICONEXCLAMATION|MB_OKCANCEL );

else

MessageBox(0,"插入失败","提示",MB_ICONEXCLAMATION|MB_OKCANCEL );

 

SQLiteStatement* stmt=sqlite.Statement("select * from File_list");

int j=0;

 

while(stmt->NextRow())

//MessageBox(0,stmt->DataType (0),"提示",MB_ICONEXCLAMATION|MB_OKCANCEL );

MessageBox(0,(stmt->ValueString(j)).c_str(),"提示",MB_ICONEXCLAMATION );

//std::cout<<stmt->DataType(0)<<" - "<<stmt->DataType (1) <<" | "<<

//stmt->ValueString(0)<<" - "<<stmt->ValueString(1)<<std::endl;

j++;

*/