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

Bob,

Ok, have a look at PreparedStatement

Essentially the same

PreparedStatement pstmt= db.prepareStatement("insert into hello values ?")
pstmt.setInt(1,intVar)
pstmt.execute()

Dave Cramer

dave.cramer(at)credativ(dot)ca
http://www.credativ.ca

On Mon, Jan 28, 2013 at 1:50 PM, Bob Futrelle <bob(dot)futrelle(at)gmail(dot)com>wrote:

> Here's a small, but complete code example - Bob
>
> package 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> 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>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
>>>
>>>
>>
>