nfxsel.ec

封装了数据库的基本操作

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/*                   Database Public Function For Informix                   */
/* ------------------------------------------------------------------------- */
/*  Author : Shih Ho                                                         */
/*  Date   : March 27, 1998                                                  */
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
$include sqlca.h;
$include "dblib.h";
$include "nfxprv.h";

$define	SQLDESC	"sqldesc";

/*===========================================================================*/
/* Public Funciton - DBselect                                                */
/*---------------------------------------------------------------------------*/
int DBselect( Command, Buffer, SaveBuf )
EXEC SQL BEGIN DECLARE SECTION;
char *Command;
EXEC SQL END DECLARE SECTION;
char *Buffer;
int  ( *SaveBuf )();
{
  int r = -1;
  EXEC SQL BEGIN DECLARE SECTION;
  int c;
  int n=0;
  char ExeName[8];
  char CsrName[8];
  char DatName[8];
  EXEC SQL END DECLARE SECTION;

  if( Command != NULL ){
    strcpy( ExeName, "exe_cmd" );
    if( ( c = GetFieldCount( Command, ExeName ) ) > 0 ){
      strcpy( CsrName, "csr_cmd" );
      EXEC SQL DECLARE :CsrName CURSOR FOR :ExeName;
      if( ( r = sqlca.sqlcode ) == SQLOK ){
        strcpy( DatName, "dat_cmd" );
        EXEC SQL ALLOCATE DESCRIPTOR :DatName WITH MAX :c;
        if( ( r = sqlca.sqlcode ) == SQLOK ){
          EXEC SQL OPEN :CsrName;
          if( ( r = sqlca.sqlcode ) == SQLOK ){
            EXEC SQL DESCRIBE :ExeName USING SQL DESCRIPTOR :DatName;
            if( ( r = sqlca.sqlcode ) == SQLOK ){
              if( Buffer == NULL ){
                EXEC SQL FETCH :CsrName USING SQL DESCRIPTOR :DatName;
                r = sqlca.sqlcode;
              }
              else{
                while( 1 ){
                  EXEC SQL FETCH :CsrName USING SQL DESCRIPTOR :DatName;
                  if( sqlca.sqlcode == SQLNOTFOUND ){
                    if( !n )
                      r = -4;
                    break;
                  }
                  n++;
                  if( ( r = sqlca.sqlcode ) != SQLOK )
                    break;
                  if( Buffer == NULL ){
                    if( n )
                      r = 0;
                    break;
                  }
                  if( ( r = GetDataBuffer( DatName, Buffer ) ) != 0 ){
                    r = -5;
                    break;
                  }
                  if( SaveBuf == NULL )
                    break;
                  if( ( *SaveBuf )( Buffer ) != 0 ){
                    r = -3;
                    break;
                  }
                }
              }
            }
            EXEC SQL CLOSE :CsrName;
          }
          EXEC SQL DEALLOCATE DESCRIPTOR :DatName;
        }
        EXEC SQL FREE :CsrName;
      }
      EXEC SQL FREE :ExeName;
    }
  }
  return( r );
}

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