C / C++ / MFC

4-Oct-06 1:05

i've used the wizzard to add class derived from CRecordset for an access table (let's say CRSmytable).

i get "Too few parameters. Expected 3" exception thrown by CRSmytable.Open().

Any ideea why? Or, at least..what does this exception mean?

Rajesh R Subramanian4-Oct-06 1:22

Rajesh R Subramanian

4-Oct-06 1:22

The exception means what it says. You are passing fewer parameters to the function CRecordSet::Open() than what it expects. BTW Can you post the code?

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eusto4-Oct-06 1:25

4-Oct-06 1:25

i'm not passing any arguments..
The constructor of the recordset recieves a pointer to the opend connection to the database. From what i know, it should do a "select * from table"...

the code:

CRSLoads line(&pApp->db);
    line.Open();

Hamid_RT4-Oct-06 9:31

Hamid_RT

4-Oct-06 9:31

And if you set parameters for it what happens?

WhiteSky

_AnsHUMAN_ 4-Oct-06 1:23

_AnsHUMAN_

4-Oct-06 1:23

eusto wrote:
Too few parameters. Expected 3

You are passing less parameter's to the function where you are calling it.See if you are missing out on passing some parameter values to the function.

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

eusto4-Oct-06 1:35

4-Oct-06 1:35

CRecordset::Open() with no params should work..it works with firebird and mysql. It actually works with other tables in the access db that i use except this one Frown | :(

I don't get it

eusto4-Oct-06 2:07

4-Oct-06 2:07

I'll reply to my own post so maybe someone would benefit from it
The error was caused by the class wizzard wich inserted some columns that did not belong to that table. 3 of them

David Crow4-Oct-06 3:00

David Crow

4-Oct-06 3:00

It means there is a discrepency between the number of columns being retrieved with the SELECT statement and the number of variables in the record set. Everything must match!

I would also suggest setting a breakpoint within CRecordset::Open() and single-stepping through that method so you'll know exactly what is going on. Until you can narrow an exception or an assertion down to the actual line, you're just guessing.

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eusto4-Oct-06 21:05

4-Oct-06 21:05

Thanks i've solved it. It was exactly what you've said. I'm not used to access, i usually had a sql server behind my applications. The problem was between keyboard and my chair. I've generated the recordset from one db file and was running the program on another one.

reallocation with new

Kiran Pinjala4-Oct-06 0:38

Kiran Pinjala

4-Oct-06 0:38

As we can reallocate memory to the memory which was allocated withe calloc() function,using realloc()
How can we reallocate memeory for the memory which was allocated using new operator.

KIRAN PINJARLA

toxcct4-Oct-06 0:44

toxcct

4-Oct-06 0:44

no way with new/delete.

BTW, what are you trying to achieve ?
if you're coding a container like a linked list, have you thought to use the STL ?

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Link20064-Oct-06 0:59

Link2006

4-Oct-06 0:59

It doesn't work that way in C++. You have to write your own function to reallocate memory that's allocated with new, or you can use STL. (ie, vector)

std::vector<>::resize()

Kiran Pinjala4-Oct-06 2:36

Kiran Pinjala

4-Oct-06 2:36

Thank You.
i want a to create a unsigned char * buffer whose size will be growing at runtime. For that i want to use vector<>.
how to use it for this?

first i want a BYTE* buffer[1000]; and at runtime everytime its size will be increased to 1000 and buffer of size 1000 should be appended to that buffer.
how this can be done using vector<>.

KIRAN PINJARLA

Link20064-Oct-06 4:08

Link2006

4-Oct-06 4:08

kiran.pinjarla wrote:
first i want a BYTE* buffer[1000]; and at runtime everytime its size will be increased to 1000 and buffer of size 1000 should be appended to that buffer.
how this can be done using vector<>.

Is this what you want? Not sure if that's what you're asking though.

<br />
        const int DEFAULT_SIZE = 1000;<br />
	vector< unsigned char * > buffer(DEFAULT_SIZE);<br />
<br />
	cout << "Before resize: " << buffer.size() << endl;<br />
<br />
	buffer.resize(DEFAULT_SIZE + 1000);<br />
<br />
	cout << "After resize: " << buffer.size() << endl;<br />

Before resize: 1000
After resize: 2000

benjymous4-Oct-06 4:53

benjymous

4-Oct-06 4:53

It's also worth noting that if you need the pointer to the beginning of your buffer, you can use

BYTE* pBuffer = &buffer[0]; // address of the first element of the vec

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ThatsAlok4-Oct-06 8:03

ThatsAlok

4-Oct-06 8:03

Link2006 wrote:

buffer.resize(DEFAULT_SIZE + 1000);

cout << "After resize: " << buffer.size() << endl;

sorry, but little problem.. you cannot get the string as a whole.. it every charcter has it unique character...
better you have unsigned char instead it's pointer!

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Link20064-Oct-06 12:46

Link2006

4-Oct-06 12:46

Then I would write my own append function instead of using vector.

ThatsAlok4-Oct-06 17:52

ThatsAlok

4-Oct-06 17:52

Link2006 wrote:

Then I would write my own append function instead of using vector.

Instead of that you can write your own string function.. which i believe much easier to write!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You