Prepared statement with placeholders - the order or the names are important

Question

Hi,
I'll explain my question, using the example from the OCCI documentation.
What if I do something like:
<pre>
// note the order
stmt->setSQL("BEGIN countFruit(:2, :1); END:");
stmt->setString(1, "Apples");
stmt->setString(2, "Oranges");
</pre>
This will become
<pre>
BEGIN countFruit( 'Apples', 'Oranges' ); END
</pre>
or
<pre>
BEGIN countFruit( 'Oranges', 'Apples' ); END
</pre>
So, if the answer is:
* *"the first one is correct"*, then - may I use whatever I want for placeholders (some strings, for example), just starting with ':' ?
* *"the second one is correct"*, then:
* * does this mean, that I can't use strings as placeholders (because setXXX does not take strings as first parameter, but a number - as position)
* * should I use consequent numbers, or I may use whatever I want. I mean, is this valid: "BEGIN countFruit(:13, :666); END:". So, if it is, does this mean, that I should use setXXX( 13, ...) and setXXX( 666, ...), instead of setXXX(1, ...) and setXXX(2, ...) ?
Sorry for the dummy questions, but I didn't see this explained in the doc (at least for 10g). And yes, I can test it, but this doesn't mean anything, it may be undefined behavior or server configuration, or whatever and I just want to be sure :)
Thanks in advance.
Best Regards,
Kiril Kirov

Answer 1

Looks like I have missed that.
I'm not sure I understand the difference, when using SQL and PL/SQL. Here's what I get, please correct me if I'm wrong:
For PL/SQL (for example - SP call), if I have
<pre>
BEGIN stored_procedure( :11, :22, :22, :33 ); END
</pre>
calling
<pre>
stmt->setString(3, "Apples");
</pre>
will set *"the third unique parameter"* - in this example, will replace ':33', right?
If so, will executing
<pre>
stmt->setString(2, "Oranges");
</pre> replace both ':22' placeholders?
And for standard SQL query, it's just the nth position. For example:
<pre>
INSERT INTO table VALUES(:11, :22, :22, :33);
</pre>
calling
<pre>
stmt->setString(3, "Apples");
</pre>
will replace the second ':22', right? It will become something like:
<pre>
INSERT INTO table VALUES(:11, :22, 'Apples', :33);
</pre>
About the summary: that would mean, that
<pre>
stmt->setSQL("BEGIN countFruit(:13, :666); END");
stmt->setString(1, "Apples");
stmt->setString(2, "Oranges");
</pre> is the correct way and it will be "translated" to:
<pre>
BEGIN countFruit( 'Apples', 'Oranges' ); END
</pre>
right?
One more case, sorry..
<pre>
stmt->setSQL("BEGIN countFruit(:1, :2, :3, :3, :2 ); END");
</pre>
How to set the second ':2' ? If ONLY "scanned left to right" is important and it stops on match (does not scan ALL parameters), does this mean, that to set the second ':2', I should use
<pre>
stmt->setString(4, "Apples");
</pre>
? Or it scans all placeholders and replaces the repeatable ones? In that case, I'll have to use
<pre>
stmt->setString(2, "Apples");
</pre>
to replace both ':2' ?
Edited by: Kiril Kirov on Jan 24, 2012 3:36 PM