OTL 4.0, Example 67 (Simple Insert/Select and otl_stream::clean() function for OTL /ODBC and MS SQL Server)

Example 67 (Simple Insert/Select and otl_stream::clean() function for OTL/ODBC and MS SQL Server)

This example demonstrates simple INSERT, SELECT and the use of the otl_stream::clean() function for OTL/ODBC and MS SQL Server..

Source Code

#include <iostream>
using namespace std;

#include <stdio.h>
#define OTL_ODBC_MSSQL_2008 // Compile OTL 4/ODBC, MS SQL 2008
//#define OTL_ODBC // Compile OTL 4/ODBC. Uncomment this when used with MS SQL 7.0/ 2000
#include <otlv4.h> // include the OTL 4.0 header file

otl_connect db; // connect object

void insert()
// insert rows into table
{
otl_stream o(10, // buffer size
"insert into test_tab values(:f1<int>,:f2<char[31]>)",
// SQL statement
db // connect object
);

o.set_commit(0); // set stream's auto-commit to OFF.

try{
o<<1<<"Line1"; // Enter one row into the stream
o.flush(); // flush the strem buffer, i.e. force
// the stream to execute
#if defined(OTL_ANSI_CPP_11_VARIADIC_TEMPLATES)
otl_write_row(o,1,"Line1");
#else
// when variadic template functions are not supported by the C++
// compiler, OTL provides nonvariadic versions of the same template
// functions in the range of [1..15] parameters
otl_write_row(o,1,"Line1");


// the old way (operators >>() / <<()) is available as always:
// o<<1<<"Line1"; // Enter the same data into the stream
// and cause a "duplicate key" error.
#endif
o.flush();
}catch(otl_exception& p){
if(p.code==2601){
// ... duplicate key ...
cout<<"STREAM ERROR STATE="<<o.get_error_state()<<endl;
o.clean(1); // clean up the stream's buffer
// and clean up the stream's internal
// error flag as well. By doing this,
// it's possible to recover from
// a database error without closing
// the stream. Remember, the number of
// situtation when it's possible is
// limited and the recovery procedure should
// be carefully designed.
}else
throw; // re-throw the exception to the outer catch block.
}


o<<2<<"Line2"; // Enter one more row of data after
// recovering from the "duplicate key"
// error
o.flush();

db.commit(); // commit transaction

}

void select()
{
otl_stream i(10, // buffer size
"select * from test_tab",
// SELECT statement
db // connect object
);
// create select stream

int f1;
char f2[31];

#if (defined(_MSC_VER) && _MSC_VER>=1600) || defined(OTL_CPP_11_ON)
// C++11 (or higher) compiler
for(auto& it : i){
#if defined(OTL_ANSI_CPP_11_VARIADIC_TEMPLATES)
otl_read_row(it,f1,f2);
#else
// when variadic template functions are not supported by the C++
// compiler, OTL provides nonvariadic versions of the same template
// functions in the range of [1..15] parameters
otl_read_row(it,f1,f2);

// the old way (operators >>() / <<()) is available as always:
// it>>f1>>f2;
#endif
cout<<"f1="<<f1<<", f2="<<f2<<endl;
}
#else
// C++98/03 compiler
while(!i.eof()){ // while not end-of-data
i>>f1>>f2;
cout<<"f1="<<f1<<", f2="<<f2<<endl;
}
#endif

}

int main()
{
otl_connect::otl_initialize(); // initialize ODBC environment
try{

db.rlogon("scott/tiger@mssql2008"); // connect to the database

otl_cursor::direct_exec
(
db,
"drop table test_tab",
otl_exception::disabled // disable OTL exceptions
); // drop table

otl_cursor::direct_exec
(
db,
"create table test_tab(f1 int, f2 varchar(30))"
); // create table

otl_cursor::direct_exec
(
db,
"create unique index ind001 on test_tab(f1)"
); // create unique index

insert(); // insert records into table
select(); // select records from table

}

catch(otl_exception& p){ // intercept OTL exceptions
cerr<<p.code<<endl; // print out error code
cerr<<p.sqlstate<<endl; // print out error SQLSTATE
cerr<<p.msg<<endl; // print out error message
cerr<<p.stm_text<<endl; // print out SQL that caused the error
cerr<<p.var_info<<endl; // print out the variable that caused the error
}

db.logoff(); // disconnect from the database

return 0;

}

Output

STREAM ERROR STATE=1
f1=1, f2=Line1
f1=2, f2=Line2

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Copyrigh1 1996-2012, Sergei Kuchin, email: skuchin@gmail.com, skuchin@gmail.com.

Permission to use, copy, modify and redistribute this document for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.