c++ - SQLBindParameter for output varchar -

i have stored procedure has varchar output parameter:

@useridout varchar(50) output 

and in c++ code attempt bind output parameter this:

... sqlchar useridout[50]; int dbreturn = execproc(...(sqlchar**)&useridout); ...  int execproc(...sqlchar **useridout) { ...     sqlinteger cbparam7 = sql_nts;     retcode = sqlbindparameter(hstmt1, 7, sql_param_output, sql_c_char, sql_varchar, 50, 0, *useridout, 50, &cbparam7);      retcode = sqlexecdirect(hstmt1, (uchar*)"{? = call updateuser(?,?,?,?,?,?)}", sql_nts); 

i have several other input parameters, , return value stored procedure. i've tried few variations function call, , yet never in useridout. if execute stored procedure sql server proper output.

any thoughts?

per comments:

you need pass pointer useridout sqlbindparameter. passing isn't pointer useridout, rather, first bytes of useridout reinterpreted pointer.

an array implicitly converted pointer first element (and since array stored contiguously in memory, makes rest of data accessible too), don't need write &useridout, can write useridout if change type sqlchar *.

int execproc(..., sqlchar *useridout) {   ...   ... sqlbindparameter(..., useridout, 50, &cbparam7);   ... }  // call ... execproc(..., useridout); 

you could, if wish, continue work pointer useridout, requires use pointer array, not pointer pointer, , pointers arrays use awkward syntax , don't have more value pointers 1 of array's elements:

int execproc(..., sqlchar (*useridout)[50]) {   ...   ... sqlbindparameter(..., useridout, 50, &cbparam7);   ... }  // call ... execproc(..., &useridout);