Question

I am trying to call a stored procedure from VC++.

Here is what the stored procedure looks like:

public static void SqlStoredProcedure2(string name, out byte[] backup)
{
    using (SqlConnection conn = new SqlConnection("context connection=true"))
    {
        SqlCommand cmd = new SqlCommand();
        cmd.Connection = conn;
        conn.Open();
        cmd.CommandText = "SELECT EmployeePhoto FROM [dbo].[DimEmployee] where FirstName like '%@name%'";
        SqlDataReader reader = null;
        reader = cmd.ExecuteReader();
        backup = null;
        while (reader.Read())
        {
            backup = (byte[])reader["EmployeePhoto"];
        }
        conn.Close();
    }
}

And the c++ code looks like:

RETCODE retcode = SQLAllocHandle(SQL_HANDLE_STMT,hdbc,&hstmt);
retcode = SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_VARCHAR, 5, 0, "Alan", 0, &cbParm1);
unsigned char ptr[8000] = "";
cbParm2 = 8000;
retcode = SQLBindParameter(hstmt, 2, SQL_PARAM_OUTPUT, SQL_C_BINARY, SQL_VARBINARY, 0, 0, ptr, 0, &cbParm2);
retcode = SQLExecDirectA(hstmt, (UCHAR*)"{call SqlStoredProcedure2(?, ?)}", SQL_NTS);

There is no error when I check returned code but nothing comes in ptr? What is wrong here?

Answer 1

ok i resolve the issue , here is right way to call it.

    SQLRETURN retcode = SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt);
    if ( (retcode != SQL_SUCCESS) && (retcode != SQL_SUCCESS_WITH_INFO) )
    {
        printf("SQLAllocHandle(hstmt1) Failed\n\n");
        return;
    }

    retcode = SQLPrepareA(hstmt,(SQLCHAR*)"{call StoreProcedure2(?)}",SQL_NTS);

    SQLSMALLINT NumParams1, DataType1, DecimalDigits1, Nullable1;
    SQLULEN ParamSize1;
    unsigned char input1[50000] = "";
    SQLLEN inputlen1 = sizeof(input1);
    SQLINTEGER cbValue1 = sizeof(input1);//actual size of data in or out

    retcode = SQLDescribeParam(hstmt, 1, &DataType1, &ParamSize1, &DecimalDigits1, &Nullable1);
    retcode = SQLBindParameter(hstmt, 1, SQL_PARAM_OUTPUT, SQL_C_BINARY, DataType1, ParamSize1, DecimalDigits1, &input1, inputlen1 ,&cbValue1);

    retcode = SQLExecDirectA(hstmt, (UCHAR*)"{call StoreProcedure2(?)}", SQL_NTS);
    if ( (retcode != SQL_SUCCESS) && (retcode != SQL_SUCCESS_WITH_INFO) ) 
    {
        printf("SQLExecDirect Failed\n\n");
        extract_error(hstmt,SQL_HANDLE_STMT);
        return;
    }
}