Can ColumnSize argument of ODBC SQLBindParameter be strlen(param) + 1 for SQLCHAR type parameter?

问题

The example for SQLBindParameter function at http://msdn.microsoft.com/en-us/library/ms710963(v=vs.85).aspx passes the size of the character array as the ColumnSize argument (6th argument) when the C type is SQL_C_CHAR.

Quoting parts of the examples from that page:

SQLCHAR szEmployeeID[EMPLOYEE_ID_LEN];
SQL_DATE_STRUCT dsOrderDate;
SQLINTEGER cbCustID = 0, cbOrderDate = 0, cbEmployeeID = SQL_NTS;

...

retcode = SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT,
                           SQL_C_CHAR, SQL_CHAR, EMPLOYEE_ID_LEN,
                           0, szEmployeeID, 0, &cbEmployeeID);

I want to know if it is okay to pass the length of the string parameter plus 1 as the ColumnSize argument. In other words, I want to know if the following call is okay if we assume that szEmployeeID contains a null-terminated string.

retcode = SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT,
                           SQL_C_CHAR, SQL_CHAR, strlen(szEmployeeID) + 1,
                           0, szEmployeeID, 0, &cbEmployeeID);

I believe this can be very useful in calls like these:

SQLLEN nts = SQL_NTS;
retcode = SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT,
                           SQL_C_CHAR, SQL_CHAR, 6,
                           0, "hello", 0, &nts);

char *domain = "stackoverflow.com";
retcode = SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT,
                           SQL_C_CHAR, SQL_CHAR, strlen(domain) + 1,
                           0, domain, 0, &nts);

回答1:

The answer to this question is "Yes".

来源：https://stackoverflow.com/questions/5636712/can-columnsize-argument-of-odbc-sqlbindparameter-be-strlenparam-1-for-sqlcha