Re: JDBC - Need to declare variables for values in insert statement

I would recommend the reading of the excellent The Java Tutorial, that
has a very well explained section about JDBC:
http://docs.oracle.com/javase/tutorial/jdbc/index.html

and the chapter about PreparedStatements:
http://docs.oracle.com/javase/tutorial/jdbc/basics/prepared.html

Regards,

Edson Richter

Em 28/01/2013 17:09, Bob Futrelle escreveu:
> Thanks to Edson and Dave for lightning responses.
> I'm confident that your answers will do the job.
> I'll follow up on the advice AFTER I get my coffee ;-)
>
> I'm really focused on the NLP content of my research,
> but I need a DB infrastructure to do it right.
> (Not a bunch of files as in ancient times.)
>
> --- Bob
>
>
>
> On Mon, Jan 28, 2013 at 1:59 PM, Edson Richter
> <edsonrichter(at)hotmail(dot)com <mailto:edsonrichter(at)hotmail(dot)com>> wrote:
>
> You have two options:
>
> st.execute("insert into hello values ('bKey', "+f1()+")");
>
> or
>
> PreparedStatement st = db.prepareStatement("insert into hello
> values ('bKey', ?)");
> st.setInteger(1, f1());
>
>
> where 1 is the first parameter, 2 is the second parameter, and so on.
>
>
> Regards,
>
> Edson Richter
>
>
>
> Em 28/01/2013 16:50, Bob Futrelle escreveu:
>> Here's a small, but complete code example - Bob
>>
>> package us.tsos.dbs.pg <http://us.tsos.dbs.pg>;
>>
>> import java.sql.*;
>>
>> /**
>> * This is an effort to get a computed value from a Java function
>> * (or data object) included properly in the VALUES entries.
>> * So, how can I declare an SQL variable and set its value to
>> some Java value?
>> * Results viewed in pgAdmin3 with query 'select * from
>> public.hello'.
>> *
>> * Jar in classpath is postgresql-9.2-1002.jdbc4.jar
>> *
>> * @version 0.1 Mon Jan 28 EST 2013
>> * @author Bob Futrelle
>> */
>>
>> public class JDBCVariableTest {
>>
>> Connection db;
>> Statement st;
>> Boolean boo;
>>
>> public static void main(String[] args) throws SQLException {
>>
>> JDBCVariableTest testIt = new JDBCVariableTest();
>> testIt.helloVariables();
>> }
>>
>> public int f1() { return 3;}
>>
>> public void helloVariables() throws SQLException {
>>
>> int intVar = f1(); // OK in Java, but SQL/JDBC?
>>
>> try {
>> db = DriverManager.getConnection("jdbc:postgresql:Articles",
>> "robertfutrelle", "<my pw>");
>> st = db.createStatement();
>> boo = st.execute("CREATE TABLE IF NOT EXISTS hello ( Name
>> VARCHAR NOT NULL PRIMARY KEY, value int)");
>>
>> // Declare .... ??
>> // INSTEAD OF THE LITERAL 4 VALUE (which works)
>> // how do I declare a variable and assign the f1() return value to it
>> // and then include it so the value 3 appears in the inserted record?
>> //st.execute("insert into hello values('aKey',4)");
>> st.execute("insert into hello values('bKey',4)");
>> } catch (SQLException e) {
>> // TODO Auto-generated catch block
>> e.printStackTrace();
>> }
>> }
>> }
>>
>>
>>
>> On Mon, Jan 28, 2013 at 8:39 AM, Dave Cramer <pg(at)fastcrypt(dot)com
>> <mailto:pg(at)fastcrypt(dot)com>> wrote:
>>
>> Bob,
>>
>> Can you provide a snippet of code so I can understand what
>> you mean by declare ?
>>
>>
>> Dave Cramer
>>
>> dave.cramer(at)credativ(dot)ca
>> http://www.credativ.ca
>>
>>
>> On Mon, Jan 28, 2013 at 7:11 AM, Bob Futrelle
>> <bob(dot)futrelle(at)gmail(dot)com <mailto:bob(dot)futrelle(at)gmail(dot)com>> wrote:
>>
>> Do the declare statements and insert all have to be done
>> in one statement execute()?
>> That is, what is the scope of variables I declare?
>> I see a variety of syntax examples, some for older versions?
>> I'm using pg 9.2.2, so what are the rules/syntax for
>> declaring and using variables?
>>
>> Use case: I collect metadata from XML articles such as
>> title, journalName, volume, year. For each article I
>> need to create a pg table record and insert the values
>> for the various metadata items in the article.
>>
>> This is my first post to this list.
>>
>> Thanks,
>>
>> - Bob
>>
>>
>>
>
>