dataset.h

Gambas is a graphical development environment based on a Basic interpreter, like Visual Basic. It us

/**********************************************************************
 * Copyright (c) 2002, Leo Seib, Hannover
 *
 * Project:Dataset C++ Dynamic Library
 * Module: Dataset abstraction layer header file
 * Author: Leo Seib      E-Mail: [e-mail]
 * Begin: 5/04/2002
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 **********************************************************************/


#ifndef _DATASET_H
#define _DATASET_H

#include <cstdio>
#include <string>
#include "stringhelper.h"
#include <map>
#include <list>
#include "qry_dat.h"

extern "C" {
#include "gambas.h"
#include "gb_common.h"
#include "../gb.db.h"

extern GB_INTERFACE GB;


class Dataset;		// forward declaration of class Dataset


#define S_NO_CONNECTION "No active connection";

#define DB_BUFF_MAX           8*1024    // Maximum buffer's capacity

#define DB_CONNECTION_NONE	0
#define DB_CONNECTION_OK	1
#define DB_CONNECTION_BAD	2

#define DB_COMMAND_OK		0	// OK - command executed
#define DB_EMPTY_QUERY		1	// Query didn't return tuples
#define DB_TUPLES_OK		2	// Query returned tuples
#define DB_ERROR		5
#define DB_BAD_RESPONSE		6
#define DB_UNEXPECTED		7	// This shouldn't ever happen
#define DB_UNEXPECTED_RESULT   -1       //For integer functions

/******************* Class Database definition ********************

   represents  connection with database server;

******************************************************************/
class Database  {
protected:
  bool active;
  string error, // Error description
    host, port, db, login, passwd, //Login info
    sequence_table; //Sequence table for nextid

public:
/* constructor */
  Database();
/* destructor */
  ~Database();
  virtual Dataset *CreateDataset() const = 0;
/* sets a new host name */
  void setHostName(const char *newHost) { host = newHost; }
/* gets a host name */
  const char *getHostName(void) const { return host.c_str(); }
/* sets a new port */
  void setPort(const char *newPort) { port = newPort; }
/* gets a port */
  const char *getPort(void) const { return port.c_str(); }
/* sets a new database name */
  void setDatabase(const char *newDb) { db = newDb; }
/* gets a database name */
  const char *getDatabase(void) const { return db.c_str(); }
/* sets a new login to database */
  void setLogin(const char *newLogin) { login = newLogin; }
/* gets a login */
  const char *getLogin(void) const { return login.c_str(); }
/* sets a password */
  void setPasswd(const char *newPasswd) { passwd = newPasswd; }
/* gets a password */
  const char *getPasswd(void) const { return passwd.c_str(); }
/* active status is OK state */
  virtual bool isActive(void) const { return active; }
/* Set new name of sequence table */
  void setSequenceTable(const char *new_seq_table) { sequence_table = new_seq_table; };
/* Get name of sequence table */
  const char *getSequenceTable(void) { return sequence_table.c_str(); }


/* virtual methods that must be overloaded in derived classes */

  virtual int init(void) { return DB_COMMAND_OK; }
  virtual int status(void) { return DB_CONNECTION_NONE; }
  virtual int setErr(int err_code)=0;
  virtual const char *getErrorMsg(void) { return error.c_str(); }
	
  virtual int connect(void) { return DB_COMMAND_OK; }
  virtual int connectFull( const char *newDb, const char *newHost=NULL,
                      const char *newLogin=NULL, const char *newPasswd=NULL,const char *newPort=NULL);
  virtual void disconnect(void) { active = false; }
  virtual int reset(void) { return DB_COMMAND_OK; }
  virtual int create(void) { return DB_COMMAND_OK; }
  virtual int drop(void) { return DB_COMMAND_OK; }
  virtual long nextid(const char* seq_name)=0;

/* virtual methods for transaction */

  virtual void start_transaction() {};
  virtual void commit_transaction() {};
  virtual void rollback_transaction() {};

  virtual bool in_transaction() {return false;};

};

}



/******************* Class Dataset definition *********************

  global abstraction for using Databases

******************************************************************/

// define Dataset States type
enum dsStates { dsSelect, dsInsert, dsEdit, dsUpdate, dsDelete, dsInactive };
enum sqlType {sqlSelect,sqlUpdate,sqlInsert,sqlDelete,sqlExec};


typedef std::list<string> StringList;
typedef std::map<string,field_value> ParamList;


class Dataset  {
protected:
/*  char *Host     = ""; //WORK_HOST;
  char *Database = ""; //WORK_DATABASE;
  char *User     = ""; //WORK_USER;
  char *Password = ""; //WORK_PASSWORD;
*/

  Database *db;		// info about db connection
  dsStates ds_state;	        // current state
  Fields *fields_object, *edit_object;
      

  bool active;			// Is Query Opened?
  bool haveError;
  int frecno; 			// number of current row bei bewegung
  string sql;

  str_helper pars;

  ParamList plist;              // Paramlist for locate
  bool fbof, feof;
  bool autocommit;		// for transactions


/* Variables to store SQL statements */
  string empty_sql; 		// Executed when result set is empty
  string select_sql; 		// May be only single string variable

  StringList update_sql; 		// May be an array in complex queries
/* Field values for updating must has prefix :NEW_ and :OLD_ and field name
   Example:
   update  wt_story set idobject set idobject=:NEW_idobject,body=:NEW_body
   where idobject=:OLD_idobject
   Essentually fields idobject and body must present in the
   result set (select_sql statement) */

  StringList insert_sql; 		// May be an array in complex queries
/* Field values for inserting must has prefix :NEW_ and field name
   Example:
   insert into wt_story (idobject, body) values (:NEW_idobject, :NEW_body)
   Essentually fields idobject and body must present in the
   result set (select_sql statement) */

  StringList delete_sql; 		// May be an array in complex queries
/* Field values for deleing must has prefix :OLD_ and field name
   Example:
   delete from wt_story where idobject=:OLD_idobject
   Essentually field idobject must present in the
   result set (select_sql statement) */




/* Arrays for searching */
//  StringList names, values;


/* Makes direct inserts into database via mysql_query function */
  virtual void make_insert() = 0;
/* Edit SQL */
  virtual void make_edit() = 0;
/* Delete SQL */
  virtual void make_deletion() = 0;

/* This function works only with MySQL database
   Filling the fields information from select statement */
  virtual void fill_fields(void)=0;

/* Parse Sql - replacing fields with prefixes :OLD_ and :NEW_ with current values of OLD or NEW field. */
  void parse_sql(string &sql);

/* Returns old field value (for :OLD) */
  virtual const field_value f_old(const char *f);

public:

/* constructor */
  Dataset();
  Dataset(Database *newDb);

/* destructor */
  ~Dataset();

/* sets a new value of connection to database */
  void setDatabase(Database *newDb) { db = newDb; }
/* retrieves  a database which connected */
  Database *getDatabase(void) { return db; }

/* sets a new query string to database server */
  void setExecSql(const char *newSql) { sql = newSql; }
/* retrieves a query string */
  const char *getExecSql(void) { return sql.c_str(); }

/* status active is OK query */
  virtual bool isActive(void) { return active; }

  virtual void setSqlParams(const char *sqlFrmt, sqlType t, ...); 


/* error handling */
//  virtual void halt(const char *msg);
/* sequence numbers */
  virtual long nextid(const char *seq_name)=0;
/* sequence numbers */
  virtual int num_rows()= 0;

/* Open SQL query */
  virtual void open(const string &sql) = 0;
  virtual void open() = 0;
/* func. executes a query without results to return */
  virtual int  exec (const string &sql) = 0;
  virtual int  exec() = 0;
  virtual const void* getExecRes()=0;
/* as open, but with our query exept Sql */
  virtual bool query(const char *sql) = 0;
/* Close SQL Query*/
  virtual void close();
/* This function looks for field Field_name with value equal Field_value
   Returns true if found (position of dataset is set to founded position)
   and false another way (position is not changed). */
//  virtual bool lookup(char *field_name, char*field_value);
/* Refresh dataset (reopen it and set the same cursor position) */
  virtual void refresh();

/* Go to record No (starting with 0) */
  virtual bool seek(int pos=0);
/* Go to record No (starting with 1) */
  virtual bool goto_rec(int pos=1);
/* Go to the first record in dataset */
  virtual void first();
/* Go to next record in dataset */
  virtual void next();
/* Go to porevious record */
  virtual void prev();
/* Go to last record in dataset */
  virtual void last();

/* Check for Ending dataset */
  virtual bool eof(void) { return feof; }
/* Check for Begining dataset */
  virtual bool bof(void) { return fbof; }

/* Start the insert mode */
  virtual void insert();
/* Start the insert mode (alias for insert() function) */
  virtual void append() { insert(); }
/* Start the edit mode */
  virtual void edit();

/* Add changes, that were made during insert or edit states of dataset into the database */
  virtual void post();
/* Delete statements from database */
  virtual void deletion();
/* Cancel changes, made in insert or edit states of dataset */
  virtual void cancel() {};

  virtual void setParamList(const ParamList &params);
  virtual bool locate();
  virtual bool locate(const ParamList &params);
  virtual bool findNext();

/* func. retrieves a number of fields */
/* Number of fields in a record */
  virtual int field_count();       					
  virtual int fieldCount();
/* func. retrieves a field name with 'n' index */
  virtual const char *fieldName(int n);
/* func. retrieves a field index with 'fn' field name,return -1 when field name not found */
  virtual int  fieldIndex(const char *fn);
/* func. retrieves a field size */
  virtual int  fieldSize(int n);
/* func. retrieves a field type of field index NG 30/08/03*/
  virtual int fieldType(int n);

/* Set field value */
  virtual bool set_field_value(const char *f_name, const field_value &value);
/* alias for set_field_value */
  virtual bool sf(const char *f, const field_value &v) { return set_field_value(f,v); }



/* Return field name by it index */
//  virtual char *field_name(int f_index) { return field_by_index(f_index)->get_field_name(); };

/* Getting value of field for current record */
  virtual const field_value get_field_value(const char *f_name);
/* Alias to get_field_value */
  const field_value fv(const char *f) { return get_field_value(f); }

/* ------------ for transaction ------------------- */
  void set_autocommit(bool v) { autocommit = v; }
  bool get_autocommit() { return autocommit; }

/* ----------------- for debug -------------------- */
  Fields *get_fields_object() {return fields_object;};
  Fields *get_edit_object() {return edit_object;};

 private:
  void set_ds_state(dsStates new_state) {ds_state = new_state;};	
 public:
/* return ds_state value */
  dsStates get_state() {return ds_state;};

/*add a new value to select_sql*/
  void set_select_sql(const char *sel_sql);
  void set_select_sql(const string &select_sql);
/*add a new value to update_sql*/
  void add_update_sql(const char *upd_sql);
  void add_update_sql(const string &upd_sql);
/*add a new value to insert_sql*/
  void add_insert_sql(const char *ins_sql);
  void add_insert_sql(const string &ins_sql);
  /*add a new value to delete_sql*/
  void add_delete_sql(const char *del_sql);
  void add_delete_sql(const string &del_sql);

/*clear update_sql*/
  void clear_update_sql();
/*clear insert_sql*/
  void clear_insert_sql();
/*clear delete_sql*/
  void clear_delete_sql();

/*get value of select_sql*/
 const char *get_select_sql();

};

#endif