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<title>OTL 4.0, Example 33 (MS SQL Server:
otl_stream::describe_select() and result sets)</title>
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<h1 align="center">OTL 4.0, Example 33<br>
(MS SQL Server: otl_stream::describe_select() and result sets)</h1>
<h1><a name="example1"></a>Example 33 (MS SQL Server:
otl_stream::describe_select()
and result sets)</h1>
<p>This example demonstrates the <a
href="otl3_stream_class.htm#describe_select">otl_stream::describe_select</a>()
with a stored procedure call returning a result set.</p>
<h2>Source Code</h2>
<pre>#include <iostream><br>using namespace std;<br><br>#include <stdio.h></pre>
<pre>#define <a href="otl3_compile.htm#OTL_ODBC_MSSQL_2005">OTL_ODBC_MSSQL_2005</a> // Compile OTL 4/ODBC, MS SQL 2005<br>//#define OTL_ODBC // Compile OTL 4/ODBC. Uncomment this when used with MS SQL 7.0/ 2000<br>#include <otlv4.h> // include the OTL 4.0 header file<br><br><a
href="otl3_connect_class.htm">otl_connect</a> db; // connect object</pre>
<pre>void insert()<br>// insert rows into table<br>{ <br> <a
href="otl3_stream_class.htm">otl_stream</a> o(50, // buffer size<br> "insert into test_tab values(:f1<float>,:f2<char[31]>)", <br> // SQL statement<br> db // connect object<br> );<br> char tmp[32];<br><br> for(int i=1;i<=100;++i){<br> sprintf(tmp,"Name%d",i);<br> o<<(float)i<<tmp;<br> }<br>}<br><br>void select()<br>{ <br> <a
href="otl3_stream_class.htm">otl_stream</a> i(50, // buffer size<br> "{call my_proc(:f1<int>)}", // SELECT statement via stored procedure<br> db, // connect object<br> <a
href="otl3_stream_class.htm#implicit_select">otl_implicit_select</a> // implicit SELECT statement<br> ); <br> // create select stream<br> <br> <a
href="otl3_stream_class.htm#otl_column_desc">otl_column_desc</a>* desc;<br> int desc_len;<br><br> i<<4; // Before the child SELECT statement can be described,<br> // the stored procedure needs to be executed.<br> // Forcing the execution of the stored procedure by entering its input <br> // patameter.<br><br> desc=i.<a
href="otl3_stream_class.htm#describe_select">describe_select</a>(desc_len);<br><br> for(int n=0;n<desc_len;++n){<br> cout<<"========== COLUMN #"<<n+1<<" ==========="<<endl;<br> cout<<"name="<<desc[n].name<<endl;<br> cout<<"dbtype="<<desc[n].dbtype<<endl;<br> cout<<"<a
href="otl3_stream_class.htm#otl_var_dbtype">otl_var_dbtype</a>="<<desc[n].otl_var_dbtype<<endl;<br> cout<<"dbsize="<<desc[n].dbsize<<endl;<br> cout<<"scale="<<desc[n].scale<<endl;<br> cout<<"prec="<<desc[n].prec<<endl;<br> cout<<"nullok="<<desc[n].nullok<<endl;<br> }<br> <br><br>}<br><br>int main()<br>{<br> <a
href="otl3_connect_class.htm">otl_connect::otl_initialize</a>(); // initialize ODBC environment<br> try{<br><br> db.rlogon("uid=scott;pwd=tiger;dsn=mssql"); // connect to ODBC<br><br> <a
href="otl3_const_sql.htm">otl_cursor::direct_exec<br></a> (<br> db,<br> "drop table test_tab",<br> otl_exception::disabled // disable OTL exceptions<br> ); // drop table<br><br> <a
href="otl3_const_sql.htm">otl_cursor::direct_exec<br></a> (<br> db,<br> "create table test_tab(f1 int, f2 varchar(30))"<br> ); // create table<br><br> otl_cursor::direct_exec<br> (<br> db,<br> "CREATE PROCEDURE my_proc "<br> " @F1 int "<br> "AS "<br> "SELECT * FROM test_tab "<br> "WHERE f1>=@F1 AND f1<=@F1*2 "<br> ); // create stored procedure<br><br> insert(); // insert record into table<br> select(); // select records from table<br><br> }<br><br> catch(<a
href="otl3_exception_class.htm">otl_exception</a>& p){ // intercept OTL exceptions<br> cerr<<p.msg<<endl; // print out error message<br> cerr<<p.stm_text<<endl; // print out SQL that caused the error<br> cerr<<p.sqlstate<<endl; // print out SQLSTATE message<br> cerr<<p.var_info<<endl; // print out the variable that caused the error<br> }<br><br> db.logoff(); // disconnect from ODBC<br><br> return 0;<br><br>}<br></pre>
<h2>Output</h2>
<pre>========== COLUMN #1 ===========<br>name=f1<br>dbtype=4<br>otl_var_dbtype=2<br>dbsize=10<br>scale=0<br>prec=10<br>nullok=1<br>========== COLUMN #2 ===========<br>name=f2<br>dbtype=12<br>otl_var_dbtype=1<br>dbsize=30<br>scale=0<br>prec=30<br>nullok=1</pre>
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<p>Copyright © 1996, 2008, Sergei Kuchin, email: <a
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