Forums  +  C++ and Sockets  +  C++ and SQL: MySQL, sqlite, ODBC  +  Miscellaneous Projects

Search Site ~Database~  Designer  ~ C++ ~  mysql C++   sqlite C++   odbc C++   sql2class   Tutorial  ~Contact~ message board  email author   visit project   homepage at   freshmeat.net

Query Class Reference SQL Statement execute / result. More... #include <Query.h> Collaboration diagram for Query: List of all members. Public Member Functions   Query (Database &dbin)   Constructor accepting reference to database object.   Query (Database &dbin, const std::string &sql)   Constructor accepting reference to database object and query string to execute.   ~Query () bool  Connected ()   Check if database object is connectable. Database &  GetDatabase () const   Return reference to database object. const std::string &  GetLastQuery ()   Return string containing last query executed. bool  execute (const std::string &sql)   execute() returns true if query is successful, does not store result. sqlite3_stmt *  get_result (const std::string &sql)   Execute query and store result. void  free_result ()   Free stored result, must be called after get_result() before calling execute()/get_result() again. bool  fetch_row ()   Fetch next result row. sqlite_int64  insert_id ()   Get id of last insert. long  num_rows ()   Returns 0 if there are no rows to fetch. int  num_cols ()   Number of columns in current result. std::string  GetError ()   Last error string. int  GetErrno ()   Last error code. bool  is_null (int x)   Check if column x in current row is null. const char *  get_string (const std::string &sql)   Execute query and return first result as a string. long  get_count (const std::string &sql)   Execute query and return first result as a long integer. double  get_num (const std::string &sql)   Execute query and return first result as a double. const char *  getstr (const std::string &x)   Return column named x as a string value. const char *  getstr (int x)   Return column x as a string value. const char *  getstr ()   Return next column as a string value - see rowcount. long  getval (const std::string &x)   Return column named x as a long integer. long  getval (int x)   Return column x as a long integer. long  getval ()   Return next column as a long integer - see rowcount. unsigned long  getuval (const std::string &x)   Return column named x as an unsigned long integer. unsigned long  getuval (int x)   Return column x as an unsigned long integer. unsigned long  getuval ()   Return next column as an unsigned long integer. int64_t  getbigint (const std::string &x)   Return column named x as a 64-bit integer value. int64_t  getbigint (int x)   Return column x as a 64-bit integer value. int64_t  getbigint ()   Return next column as a 64-bit integer value. uint64_t  getubigint (const std::string &x)   Return column named x as an unsigned 64-bit integer value. uint64_t  getubigint (int x)   Return column x as an unsigned 64-bit integer value. uint64_t  getubigint ()   Return next column as an unsigned 64-bit integer value. double  getnum (const std::string &x)   Return column named x as a double. double  getnum (int x)   Return column x as a double. double  getnum ()   Return next column as a double. Private Member Functions   Query (const Query &q)   Hide the copy constructor. Query &  operator= (const Query &)   Hide the assignment operator. void  ViewRes ()   Print current result to stdout. void  error (const std::string &)   Print error to debug class. Private Attributes Database &  m_db   Reference to database object. Database::OPENDB *  odb   Connection pool handle. sqlite3_stmt *  res   Stored result. bool  row   true if fetch_row succeeded short  rowcount   Current column pointer in result. std::string  m_tmpstr   Used to store result in get_string() call. std::string  m_last_query   Last query executed. int  cache_rc   Cached result after call to get_result(). bool  cache_rc_valid   Indicates cache_rc is valid. int  m_row_count   0 if get_result() returned no rows std::map< std::string, int >  m_nmap   map translating column names to index int  m_num_cols   number of columns in result Detailed Description SQL Statement execute / result. Definition at line 55 of file Query.h. Constructor & Destructor Documentation Query::Query ( Database &  dbin  )  Constructor accepting reference to database object. Definition at line 52 of file Query.cpp. : m_db(dbin) ,odb(dbin.grabdb()) ,res(NULL) ,row(false) ,cache_rc(0) ,cache_rc_valid(false) ,m_row_count(0) ,m_num_cols(0) { } Query::Query ( Database &  dbin, const std::string &  sql   ) Constructor accepting reference to database object and query string to execute. Definition at line 65 of file Query.cpp. References execute(). : m_db(dbin) ,odb(dbin.grabdb()) ,res(NULL) ,row(false) ,cache_rc(0) ,cache_rc_valid(false) ,m_row_count(0) ,m_num_cols(0) { execute(sql); } Query::~Query (  )  Definition at line 79 of file Query.cpp. References Database::error(), Database::freedb(), GetDatabase(), m_db, odb, and res. { if (res) { GetDatabase().error(*this, "sqlite3_finalize in destructor"); sqlite3_finalize(res); } if (odb) { m_db.freedb(odb); } } Query::Query ( const Query &  q  )  [inline, private] Hide the copy constructor. Definition at line 149 of file Query.h. : m_db(q.GetDatabase()) {} Member Function Documentation bool Query::Connected (  )  Check if database object is connectable. Definition at line 505 of file Query.cpp. References odb. { return odb ? true : false; } Database & Query::GetDatabase (  )  const Return reference to database object. Definition at line 93 of file Query.cpp. References m_db. Referenced by error(), execute(), fetch_row(), get_result(), and ~Query(). { return m_db; } const std::string & Query::GetLastQuery (  )  Return string containing last query executed. Definition at line 483 of file Query.cpp. References m_last_query. Referenced by SysLog::error(), and StderrLog::error(). { return m_last_query; } bool Query::execute ( const std::string &  sql  )  execute() returns true if query is successful, does not store result. Definition at line 103 of file Query.cpp. References Database::error(), GetDatabase(), m_last_query, odb, and res. Referenced by main(), and Query(). { // query, no result m_last_query = sql; if (odb && res) { GetDatabase().error(*this, "execute: query busy"); } if (odb && !res) { const char *s = NULL; int rc = sqlite3_prepare(odb -> db, sql.c_str(), sql.size(), &res, &s); if (rc != SQLITE_OK) { GetDatabase().error(*this, "execute: prepare query failed"); return false; } if (!res) { GetDatabase().error(*this, "execute: query failed"); return false; } rc = sqlite3_step(res); // execute sqlite3_finalize(res); // deallocate statement res = NULL; switch (rc) { case SQLITE_BUSY: GetDatabase().error(*this, "execute: database busy"); return false; case SQLITE_DONE: case SQLITE_ROW: return true; case SQLITE_ERROR: GetDatabase().error(*this, sqlite3_errmsg(odb -> db)); return false; case SQLITE_MISUSE: GetDatabase().error(*this, "execute: database misuse"); return false; } GetDatabase().error(*this, "execute: unknown result code"); } return false; } sqlite3_stmt * Query::get_result ( const std::string &  sql  )  Execute query and store result. Definition at line 152 of file Query.cpp. References cache_rc, cache_rc_valid, Database::error(), GetDatabase(), m_last_query, m_nmap, m_num_cols, m_row_count, odb, and res. Referenced by get_count(), get_num(), get_string(), and main(). { // query, result m_last_query = sql; if (odb && res) { GetDatabase().error(*this, "get_result: query busy"); } if (odb && !res) { const char *s = NULL; int rc = sqlite3_prepare(odb -> db, sql.c_str(), sql.size(), &res, &s); if (rc != SQLITE_OK) { GetDatabase().error(*this, "get_result: prepare query failed"); return NULL; } if (!res) { GetDatabase().error(*this, "get_result: query failed"); return NULL; } // get column names from result { int i = 0; do { const char *p = sqlite3_column_name(res, i); if (!p) break; m_nmap[p] = ++i; } while (true); m_num_cols = i; } cache_rc = sqlite3_step(res); cache_rc_valid = true; m_row_count = (cache_rc == SQLITE_ROW) ? 1 : 0; } return res; } void Query::free_result (  )  Free stored result, must be called after get_result() before calling execute()/get_result() again. Definition at line 194 of file Query.cpp. References cache_rc_valid, m_nmap, odb, res, and row. Referenced by get_count(), get_num(), get_string(), and main(). { if (odb && res) { sqlite3_finalize(res); res = NULL; row = false; cache_rc_valid = false; } // clear column names while (m_nmap.size()) { std::map<std::string,int>::iterator it = m_nmap.begin(); m_nmap.erase(it); } } bool Query::fetch_row (  )  Fetch next result row. Returns: false if there was no row to fetch (end of rows) Definition at line 212 of file Query.cpp. References cache_rc, cache_rc_valid, Database::error(), GetDatabase(), odb, res, row, and rowcount. Referenced by get_count(), get_num(), get_string(), and main(). { rowcount = 0; row = false; if (odb && res) { int rc = cache_rc_valid ? cache_rc : sqlite3_step(res); // execute cache_rc_valid = false; switch (rc) { case SQLITE_BUSY: GetDatabase().error(*this, "execute: database busy"); return false; case SQLITE_DONE: return false; case SQLITE_ROW: row = true; return true; case SQLITE_ERROR: GetDatabase().error(*this, sqlite3_errmsg(odb -> db)); return false; case SQLITE_MISUSE: GetDatabase().error(*this, "execute: database misuse"); return false; } GetDatabase().error(*this, "execute: unknown result code"); } return false; } sqlite_int64 Query::insert_id (  )  Get id of last insert. Definition at line 243 of file Query.cpp. References odb. { if (odb) { return sqlite3_last_insert_rowid(odb -> db); } else { return 0; } } long Query::num_rows (  )  Returns 0 if there are no rows to fetch. Definition at line 256 of file Query.cpp. References m_row_count, odb, and res. { return odb && res ? m_row_count : 0; } int Query::num_cols (  )  Number of columns in current result. Definition at line 262 of file Query.cpp. References m_num_cols. { return m_num_cols; } std::string Query::GetError (  )  Last error string. Definition at line 489 of file Query.cpp. References odb. Referenced by SysLog::error(), and StderrLog::error(). { if (odb) return sqlite3_errmsg(odb -> db); return ""; } int Query::GetErrno (  )  Last error code. Definition at line 497 of file Query.cpp. References odb. Referenced by SysLog::error(), and StderrLog::error(). { if (odb) return sqlite3_errcode(odb -> db); return 0; } bool Query::is_null ( int  x  )  Check if column x in current row is null. Definition at line 268 of file Query.cpp. References odb, res, and row. { if (odb && res && row) { if (sqlite3_column_type(res, x) == SQLITE_NULL) return true; } return false; // ... } const char * Query::get_string ( const std::string &  sql  )  Execute query and return first result as a string. Definition at line 466 of file Query.cpp. References fetch_row(), free_result(), get_result(), getstr(), and m_tmpstr. { bool found = false; m_tmpstr = ""; if (get_result(sql)) { if (fetch_row()) { m_tmpstr = getstr(); found = true; } free_result(); } return m_tmpstr.c_str(); // %! changed from 1.0 which didn't return NULL on failed query } long Query::get_count ( const std::string &  sql  )  Execute query and return first result as a long integer. Definition at line 453 of file Query.cpp. References fetch_row(), free_result(), get_result(), and getval(). { long l = 0; if (get_result(sql)) { if (fetch_row()) l = getval(); free_result(); } return l; } double Query::get_num ( const std::string &  sql  )  Execute query and return first result as a double. Definition at line 438 of file Query.cpp. References fetch_row(), free_result(), get_result(), and getnum(). { double l = 0; if (get_result(sql)) { if (fetch_row()) { l = getnum(); } free_result(); } return l; } const char * Query::getstr ( const std::string &  x  )  Return column named x as a string value. Definition at line 279 of file Query.cpp. References error(), getstr(), and m_nmap. Referenced by main(). { int index = m_nmap[x] - 1; if (index >= 0) return getstr(index); error("Column name lookup failure: " + x); return ""; } const char * Query::getstr ( int  x  )  Return column x as a string value. Definition at line 289 of file Query.cpp. References odb, res, and row. { if (odb && res && row && x < sqlite3_column_count(res) ) { const unsigned char *tmp = sqlite3_column_text(res, x); return tmp ? (const char *)tmp : ""; } return ""; } const char * Query::getstr (  )  Return next column as a string value - see rowcount. Definition at line 300 of file Query.cpp. References rowcount. Referenced by get_string(), and getstr(). { return getstr(rowcount++); } long Query::getval ( const std::string &  x  )  Return column named x as a long integer. Definition at line 326 of file Query.cpp. References error(), getval(), and m_nmap. Referenced by main(). { int index = m_nmap[x] - 1; if (index >= 0) return getval(index); error("Column name lookup failure: " + x); return 0; } long Query::getval ( int  x  )  Return column x as a long integer. Definition at line 336 of file Query.cpp. References odb, res, and row. { if (odb && res && row) { return sqlite3_column_int(res, x); } return 0; } long Query::getval (  )  Return next column as a long integer - see rowcount. Definition at line 352 of file Query.cpp. References rowcount. Referenced by get_count(), and getval(). { return getval(rowcount++); } unsigned long Query::getuval ( const std::string &  x  )  Return column named x as an unsigned long integer. Definition at line 358 of file Query.cpp. References error(), getuval(), and m_nmap. { int index = m_nmap[x] - 1; if (index >= 0) return getuval(index); error("Column name lookup failure: " + x); return 0; } unsigned long Query::getuval ( int  x  )  Return column x as an unsigned long integer. Definition at line 368 of file Query.cpp. References odb, res, and row. { unsigned long l = 0; if (odb && res && row) { l = sqlite3_column_int(res, x); } return l; } unsigned long Query::getuval (  )  Return next column as an unsigned long integer. Definition at line 379 of file Query.cpp. References rowcount. Referenced by getuval(). { return getuval(rowcount++); } int64_t Query::getbigint ( const std::string &  x  )  Return column named x as a 64-bit integer value. Definition at line 385 of file Query.cpp. References error(), getbigint(), and m_nmap. { int index = m_nmap[x] - 1; if (index >= 0) return getbigint(index); error("Column name lookup failure: " + x); return 0; } int64_t Query::getbigint ( int  x  )  Return column x as a 64-bit integer value. Definition at line 395 of file Query.cpp. References odb, res, and row. { if (odb && res && row) { return sqlite3_column_int64(res, x); } return 0; } int64_t Query::getbigint (  )  Return next column as a 64-bit integer value. Definition at line 405 of file Query.cpp. References rowcount. Referenced by getbigint(). { return getbigint(rowcount++); } uint64_t Query::getubigint ( const std::string &  x  )  Return column named x as an unsigned 64-bit integer value. Definition at line 411 of file Query.cpp. References error(), getubigint(), and m_nmap. { int index = m_nmap[x] - 1; if (index >= 0) return getubigint(index); error("Column name lookup failure: " + x); return 0; } uint64_t Query::getubigint ( int  x  )  Return column x as an unsigned 64-bit integer value. Definition at line 421 of file Query.cpp. References odb, res, and row. { uint64_t l = 0; if (odb && res && row) { l = sqlite3_column_int64(res, x); } return l; } uint64_t Query::getubigint (  )  Return next column as an unsigned 64-bit integer value. Definition at line 432 of file Query.cpp. References rowcount. Referenced by getubigint(). { return getubigint(rowcount++); } double Query::getnum ( const std::string &  x  )  Return column named x as a double. Definition at line 306 of file Query.cpp. References error(), getnum(), and m_nmap. { int index = m_nmap[x] - 1; if (index >= 0) return getnum(index); error("Column name lookup failure: " + x); return 0; } double Query::getnum ( int  x  )  Return column x as a double. Definition at line 316 of file Query.cpp. References odb, res, and row. { if (odb && res && row) { return sqlite3_column_double(res, x); } return 0; } double Query::getnum (  )  Return next column as a double. Definition at line 346 of file Query.cpp. References rowcount. Referenced by get_num(), and getnum(). { return getnum(rowcount++); } Query& Query::operator= ( const Query &   )  [inline, private] Hide the assignment operator. Definition at line 151 of file Query.h. { return *this; } void Query::ViewRes (  )  [private] Print current result to stdout. Definition at line 513 of file Query.cpp. References res. { if (!res) { printf("no result stored\n"); return; } printf("result column count = %d\n", sqlite3_column_count(res)); for (int i = 0; i < sqlite3_column_count(res); i++) { printf(" %2d type %d name '%s'", i, sqlite3_column_type(res, i), sqlite3_column_name(res, i)); printf(" / '%s'", (char *)sqlite3_column_text(res, i)); printf(" / %d", sqlite3_column_int(res, i)); printf(" / %f", sqlite3_column_double(res, i)); printf("\n"); } } void Query::error ( const std::string &   )  [private] Print error to debug class. Definition at line 532 of file Query.cpp. References Database::error(), and GetDatabase(). Referenced by getbigint(), getnum(), getstr(), getubigint(), getuval(), and getval(). { GetDatabase().error(*this, msg); } Member Data Documentation Database& Query::m_db [private] Reference to database object. Definition at line 156 of file Query.h. Referenced by GetDatabase(), and ~Query(). Database::OPENDB* Query::odb [private] Connection pool handle. Definition at line 157 of file Query.h. Referenced by Connected(), execute(), fetch_row(), free_result(), get_result(), getbigint(), GetErrno(), GetError(), getnum(), getstr(), getubigint(), getuval(), getval(), insert_id(), is_null(), num_rows(), and ~Query(). sqlite3_stmt* Query::res [private] Stored result. Definition at line 158 of file Query.h. Referenced by execute(), fetch_row(), free_result(), get_result(), getbigint(), getnum(), getstr(), getubigint(), getuval(), getval(), is_null(), num_rows(), ViewRes(), and ~Query(). bool Query::row [private] true if fetch_row succeeded Definition at line 159 of file Query.h. Referenced by fetch_row(), free_result(), getbigint(), getnum(), getstr(), getubigint(), getuval(), getval(), and is_null(). short Query::rowcount [private] Current column pointer in result. Definition at line 160 of file Query.h. Referenced by fetch_row(), getbigint(), getnum(), getstr(), getubigint(), getuval(), and getval(). std::string Query::m_tmpstr [private] Used to store result in get_string() call. Definition at line 161 of file Query.h. Referenced by get_string(). std::string Query::m_last_query [private] Last query executed. Definition at line 162 of file Query.h. Referenced by execute(), get_result(), and GetLastQuery(). int Query::cache_rc [private] Cached result after call to get_result(). Definition at line 163 of file Query.h. Referenced by fetch_row(), and get_result(). bool Query::cache_rc_valid [private] Indicates cache_rc is valid. Definition at line 164 of file Query.h. Referenced by fetch_row(), free_result(), and get_result(). int Query::m_row_count [private] 0 if get_result() returned no rows Definition at line 165 of file Query.h. Referenced by get_result(), and num_rows(). std::map<std::string,int> Query::m_nmap [private] map translating column names to index Definition at line 167 of file Query.h. Referenced by free_result(), get_result(), getbigint(), getnum(), getstr(), getubigint(), getuval(), and getval(). int Query::m_num_cols [private] number of columns in result Definition at line 168 of file Query.h. Referenced by get_result(), and num_cols(). The documentation for this class was generated from the following files: Query.h Query.cpp

Page, code, and content Copyright (C) 2006 by Anders Hedström