db.c

bonddb 是一个源于PostgreSQL封装包的对象。它是一个由C/C++编写的快速数据提取层应用软件

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <glib.h>

#include "debug.h"
#include "dbwrapper.h"

#include "db.h"
#include "dbclient.h"
#include "dbgather.h"
#include "dbobject.h"
#include "dbconstraint.h"
#include "dbtoliet.h"
#include "dbuniqueid.h"
#include "dbbureaucrat.h"
#include "dbsuggest.h"
#include "dbbirth.h"
#include "dbobjectnav.h"
#include "dbobjectdel.h"
#include "dbsqlparse.h"

/**
 * db_getvalue:
 * @obj: Database object
 * @field: Field name
 * @table: a class to look up in, or NULL if the current class.
 * @retval: Where to set the string after i've got the value.
 *
 * Toplevel function.  Retreives information from the database. 
 *
 * Returns: non-zero on failure.
 */
gint
db_getvalue(Object * obj, gchar * field, gchar * table, gchar ** retval)
   {
   gint rval;
   DbSuggest *suggest;
   g_assert(obj);
   *retval = NULL;
	if (obj->row >= obj->num || obj->row < 0)
		{
		debugmsg("Unable to read, your outside of range for your current row. (%d of %d)",obj->row,obj->num);
		return -2;
		}
   /* Establish if field is a remote location. Null will be returned if it cna't be done */
   suggest = db_suggest_all(obj, field, table);
   if (suggest->err != 0)
      {
      errormsg("Unable to find values for %s.%s. Aborting.", table, field);
		db_suggest_free(suggest);
      return -1;
      }

   rval = db_obj_doread(suggest->obj, suggest->fieldname, suggest->tablename, retval);
   if (rval < 0)
      warningmsg("error was encounted");
	
	db_suggest_free(suggest);

   return rval;
   }

/* create an empty object ready for stuff to be done to it */

/**
 * db_createobject:
 * @tablename: Name of a table where the record will be inserted
 *
 * Will create a fresh new database object ready for use.  If %NULL is passed into @tablename
 * then this record isn't used for updating back to the database, just reading.
 *
 * Returns: A newly created database object, or %NULL on error.
 */
Object *
db_createobject(gchar * tablename)
   {
   Object *obj;

   obj = db_obj_create(tablename);
   obj->numfield = db_numfields(obj);
   db_obj_handle_new_recordset(obj);

   /* Arr ok this should do stuff now.. . */
   return obj;
   }

/**
 * db_freeobject:
 * @obj: Database object
 *
 * Free up a database object, both clean up recordsets and all allocated memory. It will also
 * be removed from the bureaucrats records.
 */
void
db_freeobject(Object * obj)
   {
   db_obj_free(obj);
   }

/**
 * db_sql:
 * @obj:
 * @sql:
 *
 * Run a SQL statement on the backend database and save the results into a Object
 *
 * Returns: returns @obj or a newly created object if @obj is %NULL
 */

/* note, request the oid field last in the list, ie select * from ... */
Object *
db_sql(Object * obj, gchar * sql)
   {
   gint typeofsql;
   gchar *targettable;
   DbRecordSet *res;
   DbUniqueId *id;
   extern DbConnection *globaldbconn;

   /* if you pass in NULL it'll create a brand new spanking object and then do some fancy stuff on it to make it safe */
   if (obj == NULL)
      obj = db_obj_create(NULL);
   typeofsql = db_sqlparse_typeofsql(sql);
   /* run the query */
   if (typeofsql == 0)
      {
      db_obj_clear(obj);
      db_obj_sqlread(obj, sql);
      }
   else
      {
      /* do a write */
      if (obj == NULL)
         {
         res = db_dbexec(globaldbconn, sql);
         db_dbclear(res);
         return 0;
         }
      targettable = db_sqlparse_getfirsttable(sql);
      db_obj_sqlwrite(sql, targettable, &id);
      /* db_id_updateidindex(obj, id, cache->origrow); */
      }

   /* return object */
   return obj;
   }

/* load everything in a table. oh joy */

/**
 * db_loadall:
 * @obj: Database object to load results into
 * 
 * Load all fields in a table into an object
 * 
 * Returns: non-zero on failure
 */
gint
db_loadall(Object * obj)
   {
   gchar *query;
   gint retval;

   g_assert(obj);
   query = mem_strdup_printf("SELECT * FROM %s", obj->name);
   db_obj_clear(obj);
   retval = db_obj_sqlread(obj, query);
   mem_free(query);
   return retval;
   }

/* marika needs to get ... supermarket, i from from supermarket, ...
   bazmarty price.
   tomota sauce
   pipped prunes
   potato pomps - frozen ones
   sascuages
   deviled sausages sauce in a can
   chicken stock. - real liquid stock.
*/

/**
 * db_loadobjectbyobject:
 * @obj: database object, source object
 * @destobj: database object, the returned object list
 * @desttable: destination table to load by
 * 
 * Destination object needs to be already created on your part.  What this will
 * do is run the nessary sql statements on the @destobj to make it a subset
 * of the @obj database object.
 *
 * Returns: non-zero on failure
 */
gint
db_loadobjectbyobject(Object * obj, Object * destobj, gchar * desttable)
   {
   gint retval = 0;
   gchar *query;
   DbConstraintDef *cref;
   DbTableDef *desttabledef;
   DbBirth *birth;
	/* You can't display a object from a non-saved object. */
   if (db_isnewrecord(obj) == TRUE)
      {
		if (db_isrecordchanged(obj) == FALSE)
			{
			debugmsg("Record has not changed so i will abort");
			return retval;	
			}
      /* flush the buffer if its waiting to be writtened */
		db_toliet_flushobject(obj);
      debugmsg("%s is a new record, I am flushing it so i can use it properly.", obj->name);
		retval = 1;
      }

   /* loading yourself by yourself. hmmm */
   if (strcmp(desttable, obj->name) == 0)
      {
      birth = db_birth_create(obj->id, desttable);
      query = db_birth_createsql(birth);
      db_birth_save(destobj, birth);
      retval = db_obj_sqlread(destobj, query);
		mem_free(query);
		return retval;
      }
   desttabledef = db_findtable(desttable);
   g_assert(desttabledef);
   /* TODO: expand support to have more than one table source */
   cref = db_constraint_getonmatch(desttabledef->cref, obj->name, desttable, 0);
   if (cref == NULL)
      cref = db_constraint_getonmatch(desttabledef->cref, desttable, obj->name, 0);
   if (cref == NULL)
      {
      errormsg("Unable to find a relationship between %s and %s, make sure a cref exists", obj->name, desttable);
      return -3;
      }

   /* now the sensible stuff */
   db_obj_clear(destobj);
   birth = db_birth_create(NULL, desttable);
   if(db_birth_applycref(obj, birth, cref)!=0)
		{
		db_birth_free(birth);
		return -1;
		}
   query = db_birth_createsql(birth);
   g_assert(query);
   db_birth_save(destobj, birth);
   retval = db_obj_sqlread(destobj, query);
	mem_free(query);
   /* Was there no results from this load? */
   /*if (retval == 1)
      {
      debugmsg("Spring Chickens!");
      db_birth_springchicken(destobj);
      } */
   /*debugmsg("Finishing running loadobjectbyobject, %d records",obj->num);*/
   return retval;
   }

/**
 * db_refreshobject:
 * @obj: database object
 *
 * Re-run the query on an object. This will refresh all its data and dump anything sitting
 * in the cache waiting to be flushed.
 *
 * Returns: non-zero on error
 */
gint
db_refreshobject(Object * obj)
   {
   return db_obj_refresh(obj);
   }

/* Prepare for random comment unattached to any specific code */

/* a bit more of the tricky stuff. load an object based on what
someone has selected in the first object. hmmm, yes the row does
play a part in this */

/**
 * db_debugobject:
 * @obj: database object to show information for
 * 
 * Show lots of intersting things about this object. Actually no, no it just prints a list
 * of the values for every field. boring huh?.
 * db_obj_debug() differs from thsi function in that it prints out the cache values.
 */
void
db_debugobject(Object * obj)
   {
   gchar *tmpstr;
   gint x, y;

   fprintf(debug_stream, "====== OBJECT CONTENTS =======\n");
   for (y = 0; y < obj->num; y++)

      {
      for (x = 0; x < obj->numfield; x++)
         {
         tmpstr = db_dbgetvalue(obj->res, y, x);
         fprintf(debug_stream, "%s \t", tmpstr);
         }
      fprintf(debug_stream, "\n");
      }
   fprintf(debug_stream, "==============================\n");
   }

/**
 * db_setvalue:
 * @obj: database object
 * @field
 * @table:
 * @value:
 *
 * Majical function that writes stuff to a database.  You can edit an existing recordset, create
 * a new record, and modifed a new record fields with this function.
 *
 * Returns: non-zero on failure
 */
gint
db_setvalue(Object * obj, gchar * field, gchar * table, gchar * value)
   {
   gint retval = 0;
   DbSuggest *suggest;

	if (obj->row < 0 || obj->row >= obj->num)
		{
		debugmsg("Out of range for row, will not add write");
		return -1;
		}

   suggest = db_suggest_all(obj, field, table);

   /* Establish if field is a remote location. Null will be returned if it cna't be done */
   if (suggest->err != 0)
      {
      errormsg("Unable to find values for %s.%s. Aborting.", table, field);
      return -1;
      }

   /* run man, just do it */
   retval = db_obj_addwrite(suggest->obj, suggest->fieldname, suggest->tablename, value, TRUE);
	db_suggest_free(suggest);
   return retval;
   }

/**
 * db_setvalue_nomark:
 * @obj: database object
 * @field: field to set value into
 * @table: table to set this into, leave as NULL if main table
 * @value: string to set the field to
 *
 * Majical function that writes stuff to a database.  You can edit an existing recordset, create
 * a new record, and modifed a new record fields with this function.  The difference
 * between this function doesn't record the change as perment in the object, so if nothing
 * else changes in teh object then the changes wont be saved, else they will be.
 *
 * Returns: non-zero on failure
 */
gint
db_setvalue_nomark(Object * obj, gchar * field, gchar * table, gchar * value)
   {
   gint retval = 0;
   DbSuggest *suggest;

	if (obj->row < 0 || obj->row >= obj->num)
		{
		debugmsg("Out of range for row, will not add write");
		return -1;
		}

   suggest = db_suggest_all(obj, field, table);

   /* Establish if field is a remote location. Null will be returned if it cna't be done */
   if (suggest->err != 0)
      {
      errormsg("Unable to find values for %s.%s. Aborting.", table, field);
      return -1;
      }

   /* run man, just do it */
   debugmsg("adding in some default values of %s to %s",value,suggest->fieldname);
   retval = db_obj_addwrite(suggest->obj, suggest->fieldname, suggest->tablename, value, FALSE);
	db_suggest_free(suggest);
   return retval;
   }

/**
 * db_getobjectbyfield:
 * @obj: database object
 * @field: field to load by
 * @value: value you want field to equal
 *
 * This is equivilant to a SELECT * FROM obj->name WHERE field=value.  All records that
 * match the required results will be returned. whiippi.
 *
 * Returns: non-zero on error
 */
gint
db_getobjectbyfield(Object * obj, gchar * field, gchar * value)
   {
   gint retval = 0;
   gchar *query;
   DbBirth *birth;

   g_assert(obj);

   /* clear the contents of the object before creating a new isntance of it */
   db_obj_clear(obj);
   if (obj->name == NULL)
      {
      errormsg("I have no table associated with this object, I can not proceeed as i do not know what to filter on");
      return -1;
      }
   birth = db_birth_create(NULL, obj->name);
   db_birth_addvalue(birth, field, value);
   query = db_birth_createsql(birth);
   db_birth_save(obj, birth);
   g_assert(obj->birth);
   retval = db_obj_sqlread(obj, query);
	mem_free(query);
   return retval;
   }

/**
 * db_getobjectid:
 * @obj: database object
 *
 * Get uniqueid for a object, this just returns the obj->id value. 
 *
 * Returns: %NULL on error else the unique id
 */
DbUniqueId *
db_getobjectid(Object * obj)
   {
   g_assert(obj);
	if (obj->id == NULL)
		{
		errormsg("Returning NULL objectid. This is bad");
		g_assert(obj->id);
		}
   return obj->id;
   }

/**
 * db_setrowbyfield:
 * @obj: database object
 * @fieldname: fieldname to set by
 * @value: value to equate by
 *
 * Assumes object list has already been loaded. Go though records and find one that
 * matchs criteria specified and sets row to that field. 
 *
 * Returns: non-zero on error
 */
gint
db_setrowbyfield(Object * obj, gchar * fieldname, gchar *tablename, gchar * value)
   {
   gchar *tmpstr;
   gint row = -1;
   gint i, pos = -1;
   gint oldrow;

   g_assert(obj);
   g_assert(value);
   if (obj->num == 0)
      {
      errormsg("Empty list, can't set row");
      return -2;
      }
   oldrow = obj->row;
   pos = db_field_getpos(obj, fieldname,tablename);
   if (pos < 0)
      {
      errormsg(" arr shit we here troubles. cna't find %s", fieldname);
      return -3;
      }
   for (i = 0; i < obj->num; i++)
      {
      /* move along and get the value */
      db_moveto(obj, i);
      db_obj_doread(obj, fieldname, tablename, &tmpstr);

      /* do the compare */
      if (strcmp(value, tmpstr) == 0)
         {
         row = i;