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<title>OTL 4.0, Example 183 (Simple Unicode Insert/Select with NCLOB,
and LOB streams)</title>
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<h1>OTL 4.0, Example 183 (Simple Unicode Insert/Select with NCLOB, and
LOB
streams)</h1>
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<h1>
Example 183 (Simple Unicode Insert/Select with NCLOB, and LOB streams)</h1>
This example demonstrates simple Unicode INSERT, SELECT, and constant
SQL
statements with NCLOB columns, and <a href="otl3_lob_stream.htm">LOB
streams</a>
<h2>Source Code</h2>
<pre>#include <iostream><br>using namespace std;<br><br>#include <stdio.h></pre>
<pre>#define OTL_ORA8I // Compile OTL 4.0/OCI8i<br>#define <a
href="otl3_compile.htm#OTL_UNICODE">OTL_UNICODE</a> // Enable Unicode OTL for OCI8i<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<br><br>void insert()<br>// insert rows into table<br>{ <br> <a
href="otl3_long_string.htm#otl_long_unicode_string">otl_long_unicode_string</a> f2(6000); // define long unicode string variable<br><br> <a
href="otl3_stream_class.htm">otl_stream</a> o(1, // buffer size has to be set to 1 for operations with CLOBs<br> "insert into test_tab values(:f1<int>,empty_clob()) "<br> "returning f2 into :f2<<a
href="otl3_bind_variables.htm#clob">clob</a>>",<br> // SQL statement<br> db // connect object<br> );<br><br> o.<a
href="otl3_stream_class.htm#set_commit">set_commit</a>(0); // setting stream "auto-commit" to "off". It is required<br> // when LOB stream mode is used.</pre>
<pre> <a href="otl3_lob_stream.htm">otl_lob_stream</a> lob; // LOB stream for reading/writing unlimited number<br> // of bytes regardless of the buffer size.<br><br> int i,j;<br><br> for(i=1;i<=20;++i){<br> o<<i;<br> o<<lob; // Initialize otl_lob_stream by writing it<br> // into otl_stream.<br><br> for(j=0;j<5000;++j)<br> f2[j]=(unsigned short) '*'; // ASCII to Unicode.<br> f2[5000]= (unsigned short) '?'; // ASCII to Unicode<br> f2.<a
href="otl3_long_string.htm#set_len">set_len</a>(5001);<br><br> lob.<a
href="otl3_lob_stream.htm#set_len">set_len</a>(5001+2123); // setting the total size of<br> // the CLOB to be written.<br> <br> lob<<f2; // writing first chunk of the CLOB into lob<br><br> f2[2122]= (unsigned short) '?';<br> f2.set_len(2123); // setting the size of the second chunk<br><br> lob<<f2; // writing the second chunk of the CLOB into lob<br> lob.<a
href="otl3_lob_stream.htm">close</a>(); // closing the otl_lob_stream<br><br> }<br><br> db.commit(); // committing transaction.<br><br>}<br><br>void select()<br>{ <br> <a
href="otl3_long_string.htmotl_long_unicode_string">otl_long_unicode_string</a> f2(6000); // define Unicode long string variable<br><br> <a
href="otl3_stream_class.htm">otl_stream</a> i(10, // buffer size <br> "select * from test_tab where f1>=:f<int> and f1<=:f*2",<br> // SELECT statement<br> db // connect object<br> ); <br> // create select stream<br> <br> <br> float f1;<br> <a
href="otl3_lob_stream.htm">otl_lob_stream</a> lob; // Stream for reading CLOB<br><br> i<<4; // assigning :f = 4<br> // SELECT automatically executes when all input variables are<br> // assigned. First portion of output rows is fetched to the buffer<br><br> while(!i.eof()){ // while not end-of-data<br> i>>f1;<br> cout<<"f1="<<f1<<endl;<br> i>>lob; // initializing CLOB stream by reading the CLOB reference <br> // into the otl_lob_stream from the otl_stream.<br> int n=0;<br> while(!lob.<a
href="otl3_lob_stream.htm#eof">eof</a>()){ // read while not "end-of-file" -- end of CLOB<br> ++n;<br> lob>>f2; // reading a chunk of CLOB<br> cout<<" chunk #"<<n;<br> cout<<", f2="<br> <<(char)f2[0] // Unicode to ASCII<br> <<(char)f2[f2.len()-1]<<", len="<<f2.len()<<endl;<br> }<br> lob.<a
href="otl3_lob_stream.htm#close">close</a>(); // closing the otl_lob_stream. This step may be skipped. <br> }<br>}</pre>
<pre>int main()<br>{<br> <a href="otl3_connect_class.htm">otl_connect::otl_initialize</a>(); // initialize OCI environment<br> try{<br><br> db.rlogon("scott/tiger"); // connect to Oracle<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 number, f2 nclob)"<br> ); // create table<br><br> db.<a
href="otl3_connect_class.htm#set_character_set">set_character_set</a>(SQLCS_NCHAR);<br><br> insert(); // insert records 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.var_info<<endl; // print out the variable that caused the error<br> }<br><br> db.logoff(); // disconnect from Oracle<br><br> return 0;<br><br>}</pre>
<h2>
Output</h2>
<pre>f1=4<br> chunk #1, f2=**, len=6000<br> chunk #2, f2=*?, len=1124<br>f1=5<br> chunk #1, f2=**, len=6000<br> chunk #2, f2=*?, len=1124<br>f1=6<br> chunk #1, f2=**, len=6000<br> chunk #2, f2=*?, len=1124<br>f1=7<br> chunk #1, f2=**, len=6000<br> chunk #2, f2=*?, len=1124<br>f1=8<br> chunk #1, f2=**, len=6000<br> chunk #2, f2=*?, len=1124<br><br><br><br><hr
width="100%"></pre>
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