| Server IP : 103.119.228.120 / Your IP : 13.58.38.184 Web Server : Apache System : Linux v8.techscape8.com 3.10.0-1160.119.1.el7.tuxcare.els2.x86_64 #1 SMP Mon Jul 15 12:09:18 UTC 2024 x86_64 User : nobody ( 99) PHP Version : 5.6.40 Disable Function : shell_exec,symlink,system,exec,proc_get_status,proc_nice,proc_terminate,define_syslog_variables,syslog,openlog,closelog,escapeshellcmd,passthru,ocinum cols,ini_alter,leak,listen,chgrp,apache_note,apache_setenv,debugger_on,debugger_off,ftp_exec,dl,dll,myshellexec,proc_open,socket_bind,proc_close,escapeshellarg,parse_ini_filepopen,fpassthru,exec,passthru,escapeshellarg,escapeshellcmd,proc_close,proc_open,ini_alter,popen,show_source,proc_nice,proc_terminate,proc_get_status,proc_close,pfsockopen,leak,apache_child_terminate,posix_kill,posix_mkfifo,posix_setpgid,posix_setsid,posix_setuid,dl,symlink,shell_exec,system,dl,passthru,escapeshellarg,escapeshellcmd,myshellexec,c99_buff_prepare,c99_sess_put,fpassthru,getdisfunc,fx29exec,fx29exec2,is_windows,disp_freespace,fx29sh_getupdate,fx29_buff_prepare,fx29_sess_put,fx29shexit,fx29fsearch,fx29ftpbrutecheck,fx29sh_tools,fx29sh_about,milw0rm,imagez,sh_name,myshellexec,checkproxyhost,dosyayicek,c99_buff_prepare,c99_sess_put,c99getsource,c99sh_getupdate,c99fsearch,c99shexit,view_perms,posix_getpwuid,posix_getgrgid,posix_kill,parse_perms,parsesort,view_perms_color,set_encoder_input,ls_setcheckboxall,ls_reverse_all,rsg_read,rsg_glob,selfURL,dispsecinfo,unix2DosTime,addFile,system,get_users,view_size,DirFiles,DirFilesWide,DirPrintHTMLHeaders,GetFilesTotal,GetTitles,GetTimeTotal,GetMatchesCount,GetFileMatchesCount,GetResultFiles,fs_copy_dir,fs_copy_obj,fs_move_dir,fs_move_obj,fs_rmdir,SearchText,getmicrotime MySQL : ON | cURL : ON | WGET : ON | Perl : ON | Python : ON | Sudo : ON | Pkexec : ON Directory : /usr/local/ssl/share/doc/unixODBC-2.3.1/doc/ProgrammerManual/Tutorial/ |
Upload File : |
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" content="text/html; charset=iso-8859-1">
<TITLE>Fetching Data</TITLE>
<LINK REL="StyleSheet" Href="odbc.css">
</HEAD>
<BODY bgcolor="white">
<table width="90%" cols="3" border="0">
<TR>
<TD colspan="3" class="big">Fetching data from a result set</TD>
</TR>
<TR>
<TD colspan="3"><P>If the execution of the statement went fine you are now able to fetch
the data <A Href="gloss.html#col">column</A> by column. May be you would first like to know
how many columns there are in the result set (if you use a <CODE> SELECT * FROM tkeyuser</CODE>
you wouldn't know in your program). A call to <a href="gloss.html#ccol"><CODE>SQLNumResultCols</CODE></A>.
This function takes the statement handle and a pointer to an integer variable which will yield the
number of columns after the call.</P>
Knowing that much we can add this to our program:
<CODE><PRE>
<FONT COLOR="green">// At the beginning add:</FONT>
SQLSMALLINT V_OD_colanz; <FONT COLOR="green">// Num of columns</FONT>
<FONT COLOR="green">// At the end add:</FONT>
V_OD_erg=SQLNumResultCols(V_OD_hstmt,&V_OD_colanz);
if ((V_OD_erg != SQL_SUCCESS) &&
(V_OD_erg != SQL_SUCCESS_WITH_INFO))
{
printf("Fehler im ResultCols %d\n",V_OD_erg);
SQLFreeHandle(SQL_HANDLE_STMT,V_OD_hstmt);
SQLFreeHandle(SQL_HANDLE_DBC,V_OD_hdbc);
SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
exit(0);
}
printf("Number of Columns %d\n",V_OD_colanz);
</PRE></CODE>
<P>
The next thing you need to know is how many <A href="gloss.html#row">rows</A> have
been returned by the query. A call to <A HREF="gloss.html#crow"><CODE>SQLRowCount</CODE></A> should
quench your thirst for knowledge.
</P>
<P>
The last thing to do is to fetch the data itself from the result set. You should call <A HREF="gloss.html#fetc"><CODE>SQLFetch</CODE></A>
with a statement handle (which has been allocated and <CODE>SQLBind</CODE> has been called for all columns).
<CODE>SQLFetch</CODE> returns <CODE>SQL_NO_DATA</CODE> if there is no more data in the result set.
</P>
<P>So here is the complete source code. Real C-programmers will moan in disgust
how inefficient the program is coded, but I prefer it that way (doesn't it look a little bit like PASCAL?).
Take it as a starting point for your own endeavors with ODBC.</P>
<CODE class="list"><PRE>
/* odbc.c
testing unixODBC
*/
#include <stdlib.h>
#include <stdio.h>
#include <odbc/sql.h>
#include <odbc/sqlext.h>
#include <odbc/sqltypes.h>
SQLHENV V_OD_Env; <FONT COLOR="green">// Handle ODBC environment</FONT>
long V_OD_erg; <FONT COLOR="green">// result of functions</FONT>
SQLHDBC V_OD_hdbc; <FONT COLOR="green">// Handle connection</FONT>
char V_OD_stat[10]; <FONT COLOR="green">// Status SQL</FONT>
SQLINTEGER V_OD_err,V_OD_rowanz,V_OD_id;
SQLSMALLINT V_OD_mlen,V_OD_colanz;
char V_OD_msg[200],V_OD_buffer[200];
int main(int argc,char *argv[])
{
<FONT COLOR="green">// 1. allocate Environment handle and register version </FONT>
V_OD_erg=SQLAllocHandle(SQL_HANDLE_ENV,SQL_NULL_HANDLE,&V_OD_Env);
if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
{
printf("Error AllocHandle\n");
exit(0);
}
V_OD_erg=SQLSetEnvAttr(V_OD_Env, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);
if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
{
printf("Error SetEnv\n");
SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
exit(0);
}
<FONT COLOR="green">// 2. allocate connection handle, set timeout</FONT>
V_OD_erg = SQLAllocHandle(SQL_HANDLE_DBC, V_OD_Env, &V_OD_hdbc);
if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
{
printf("Error AllocHDB %d\n",V_OD_erg);
SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
exit(0);
}
SQLSetConnectAttr(V_OD_hdbc, SQL_LOGIN_TIMEOUT, (SQLPOINTER *)5, 0);
<FONT COLOR="green">// 3. Connect to the datasource "web" </FONT>
V_OD_erg = SQLConnect(V_OD_hdbc, (SQLCHAR*) "web", SQL_NTS,
(SQLCHAR*) "christa", SQL_NTS,
(SQLCHAR*) "", SQL_NTS);
if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
{
printf("Error SQLConnect %d\n",V_OD_erg);
SQLGetDiagRec(SQL_HANDLE_DBC, V_OD_hdbc,1,
V_OD_stat, &V_OD_err,V_OD_msg,100,&V_OD_mlen);
printf("%s (%d)\n",V_OD_msg,V_OD_err);
SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
exit(0);
}
printf("Connected !\n");
V_OD_erg=SQLAllocHandle(SQL_HANDLE_STMT, V_OD_hdbc, &V_OD_hstmt);
if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
{
printf("Fehler im AllocStatement %d\n",V_OD_erg);
SQLGetDiagRec(SQL_HANDLE_DBC, V_OD_hdbc,1, V_OD_stat,&V_OD_err,V_OD_msg,100,&V_OD_mlen);
printf("%s (%d)\n",V_OD_msg,V_OD_err);
SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
exit(0);
}
SQLBindCol(V_OD_hstmt,1,SQL_C_CHAR, &V_OD_buffer,150,&V_OD_err);
SQLBindCol(V_OD_hstmt,2,SQL_C_ULONG,&V_OD_id,150,&V_OD_err);
V_OD_erg=SQLExecDirect(V_OD_hstmt,"SELECT dtname,iduser FROM tkeyuser order by iduser",SQL_NTS);
if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
{
printf("Error in Select %d\n",V_OD_erg);
SQLGetDiagRec(SQL_HANDLE_DBC, V_OD_hdbc,1, V_OD_stat,&V_OD_err,V_OD_msg,100,&V_OD_mlen);
printf("%s (%d)\n",V_OD_msg,V_OD_err);
SQLFreeHandle(SQL_HANDLE_STMT,V_OD_hstmt);
SQLFreeHandle(SQL_HANDLE_DBC,V_OD_hdbc);
SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
exit(0);
}
V_OD_erg=SQLNumResultCols(V_OD_hstmt,&V_OD_colanz);
if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
{
SQLFreeHandle(SQL_HANDLE_STMT,V_OD_hstmt);
SQLDisconnect(V_OD_hdbc);
SQLFreeHandle(SQL_HANDLE_DBC,V_OD_hdbc);
SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
exit(0);
}
printf("Number of Columns %d\n",V_OD_colanz);
V_OD_erg=SQLRowCount(V_OD_hstmt,&V_OD_rowanz);
if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))
{
printf("Number ofRowCount %d\n",V_OD_erg);
SQLFreeHandle(SQL_HANDLE_STMT,V_OD_hstmt);
SQLDisconnect(V_OD_hdbc);
SQLFreeHandle(SQL_HANDLE_DBC,V_OD_hdbc);
SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
exit(0);
}
printf("Number of Rows %d\n",V_OD_rowanz);
V_OD_erg=SQLFetch(V_OD_hstmt);
while(V_OD_erg != SQL_NO_DATA)
{
printf("Result: %d %s\n",V_OD_id,V_OD_buffer);
V_OD_erg=SQLFetch(V_OD_hstmt);
} ;
SQLFreeHandle(SQL_HANDLE_STMT,V_OD_hstmt);
SQLDisconnect(V_OD_hdbc);
SQLFreeHandle(SQL_HANDLE_DBC,V_OD_hdbc);
SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);
return(0);
}
</PRE>
</CODE>
If I find some more time I will add something about diagnostics, cursor positioning updating and and and...
</TD>
</TR>
</TABLE>
</BODY>
</HTML>