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
<edsonrich...@hotmail.com <mailto:edsonrich...@hotmail.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 <p...@fastcrypt.com
<mailto:p...@fastcrypt.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.futre...@gmail.com <mailto:bob.futre...@gmail.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
