CPDB.Net

https://cpdb.ppcompiler.org/

3- Browse operations (CPDB library)

Introduction

With CPDB you can browse your databases in any direction, with very simple functions.

Browse in simple way

To browse your database simply use this example :

// Read the first record
err = CPDB_ReadFirst(mydbHandle);
while (err == 0)
{
  // Work on the record here
  // ...
  // Go to the next record
  err = CPDB_ReadNext(mydbHandle);
}

The loop will end when CPDB_ReadNext return an error, you must verify this error, it must be a CPDB_ERR_EOF error. You can browse in the inverse direction by using CPDB_ReadLast and CPDB_ReadPrevious functions, the error will be CPDB_ERR_BOF.

Browse page by page

To browse page by page, use the CPDB_SeekForward and CPDB_SeekBackward functions. This example seek 10 records in one operation :

err = CPDB_SeekForward(mydbHandle, 10);

Note ; if the end (or begin) of the file is reached, the read operation is canceled, you must do a CPDB_ReadFirst (or Last) to complete the operation.

Browse information

A any time it is possible to know if the last browse operation have succeded, use the CPDB_IsOut function :

Boolean boolIsOut; err = CPDB_IsOut(iHandle, &boolIsOut);

If boolIsOut contain true, the last browse operation have failed, and no record is currently readed.

More information