Oci_bind_by_name

Question

Hi to all,
Can anyone explain how to use of oci_bind_by_name in more detail?
for example oci_bind_by_name(":oracle_parameter",$php_var, $maxlength [, int $type])
how do you specify the maxlength? what criteria to consider
what can you specify in $type? how do you use the $type ( actually i m more confused on this part)
what is the advancetage of using the oci_bind_by_name and how do you use these function
in my case oracle statement of mine is
$stmt = "select column1, column2 from (select column1, column2, row_num rnum from (select column1, column2 from table1) where row_num < :lastrow) where rnum> :firstrow";
$connection= oci_connect('hr', 'hr', 'orcl');
$q =oci_parse($connection, $query);
oci_bind_by_name ($q, ":firstrow" , 1); //is this possible?? because the it is bind to a number
oci_bind_by_name ($q, ":lastrow" , 1000); //??
oci_execute($q);
$q will be the array of your table blah blah.........
if you intend have the same page over and over again but just having row number change how would you use the oci_bind_by_name? do your php_page call the oci_connect again and do the binding for the page like the code above? how do you guys do to save some oracle resources...
by the way, i have also notice that if you perform a "order by" in the oracle query it does take some time...how to reduce this time..any recommendation?
thanks...
Message was edited by:
Jo Ee

Answer 1

Hi,
Best source of info is PHP Manual: http://www.php.net/function.oci_bind_by_name
1. how do you specify the maxlength? what criteria to consider
"Sets the maximum length for the bind. If you set it to -1, this function will use the current length of variable to set the maximum length."
For input parameters you can use -1 (it's easy but can cause problems with scalability, as different values causes to create new child cursor in SGA. It's better to estimate what is your max and set it)
For output variables you have to set buffer length - what is the max length that can be returned from DB.
2.what can you specify in $type?
It can be one of:
#SQLT_FILE - for BFILEs;
#SQLT_CFILE - for CFILEs;
#SQLT_CLOB - for CLOBs;
#SQLT_BLOB - for BLOBs;
#SQLT_RDD - for ROWIDs;
#SQLT_NTY - for named datatypes;
#SQLT_INT - for integers;
#SQLT_CHR - for VARCHARs;
#SQLT_BIN - for RAW columns;
#SQLT_LNG - for LONG columns;
#SQLT_LBI - for LONG RAW columns;
#SQLT_RSET - for Ref cursosr
Default is SQLT_CHR. You should set proper type, otherwise you will have implicit type conversion.
In your case try:
oci_bind_by_name ($q, ":firstrow" , 1, 10, SQLT_INT);
oci_bind_by_name ($q, ":lastrow" , 1000, 10, SQLT_INT);
3. if you intend have the same page over and over again but just having row number change how would you use the oci_bind_by_name? do your php_page call the oci_connect again and do the binding for the page like the code above?
Well, every page is new request. And for every page you have to obtain persistent connection (oci_pconnect) or create new connection (oci_connect). I recommend using persistent connections. (BTW. in Oracle 11g it is even improved by Database Resident Connection Pooling).
If you use persistent connections and cursors with bind variables, then cursors are kept parsed in session, and when you execute oci_parse existing execution plan is reused.
Regards,
Paweł