OTL 4.0, Example 239 (OTL/ODBC, accessing the system data dictionary via ODBC functions, MS SQL Server)

This example demonstrates how to access the database system data dictionary via ODBC functions, OTL/ODBC, MS SQL Server. In theory, any ODBC driver that implements the necessary ODBC functions can be used with OTL/ODBC.

Source Code

#include <iostream>
#include <stdio.h>
using namespace std;

#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 select()

 otl_stream s;

 s.set_all_column_types(otl_all_num2str|otl_all_date2str); 
    // map all numeric and date/time output columns to strings for simplicity.

 s.open(100, // buffer size
         "$SQLColumns $1:'dms' $2:'dbo' $3:'test_tab'",
         // get a list of all columns of table
// "test_tab" that belongs to schema "dbo",
// catalog "DMS"
         db // connect object
        ); 

 otl_column_desc* desc;
 int desc_len;
 desc=s.describe_select(desc_len); 
    // describe the structure of the output columns of the result set.

 int rpc=0;
 while(!s.eof()){
   ++rpc;
   char str[512];
   cout<<"ROW#"<<rpc<<" ";
   for(int col_num=0;col_num<desc_len;++col_num){
     s>>str;
     if(s.is_null())
       cout<<desc[col_num].name<<"=NULL ";
     else
       cout<<desc[col_num].name<<"="<<str<<" ";
   }
   cout<<endl;
 }

}

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

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

  select(); // query the system data dictionary via ODBC functions.

 }

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

 db.logoff(); // disconnect from ODBC

 return 0;

}

Output

ROW#1 TABLE_CAT=dms TABLE_SCHEM=dbo TABLE_NAME=test_tab COLUMN_NAME=f1 DATA_TYPE=4 TYPE_NAME=int COLUMN_SIZE=10 BUFFER_LENGTH=4 DECIMAL_DIGITS=0 NUM_PREC_RADIX=10 NULLABLE=1 REMARKS=NULL COLUMN_DEF=NULL SQL_DATA_TYPE=4 SQL_DATETIME_SUB=NULL CHAR_OCTET_LENGTH=NULL ORDINAL_POSITION=1 IS_NULLABLE=YES SS_DATA_TYPE=38 
ROW#2 TABLE_CAT=dms TABLE_SCHEM=dbo TABLE_NAME=test_tab COLUMN_NAME=f2 DATA_TYPE=12 TYPE_NAME=varchar COLUMN_SIZE=30 BUFFER_LENGTH=30 DECIMAL_DIGITS=NULL NUM_PREC_RADIX=NULL NULLABLE=1 REMARKS=NULL COLUMN_DEF=NULL SQL_DATA_TYPE=12 SQL_DATETIME_SUB=NULL CHAR_OCTET_LENGTH=30 ORDINAL_POSITION=2 IS_NULLABLE=YES SS_DATA_TYPE=39


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Copyright © 1996-2017, Sergei Kuchin, email: skuchin@gmail.com, skuchin@gmail.com .

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