Обсуждение: Ver. 12.1 successfully installed on Win 10 but having trouble withjdbc jar

Hi,

I have postgresql-12.1-3-windows-x64 installed and apparently working, but I'm then I'm trying a simple Java connection example as follows:

import java.sql.*;

public class CreateTable {
    public static void main(String args[]) {
        Connection c = null;
        Statement stmt = null;
        String CreateSql = null;

        try {
            Class.forName("org.postgresql.Driver");
            c = DriverManager.getConnection("jdbc:postgresql://localhost:5432/procedure_demo", "postgres", "adminedb");
            System.out.println("Database Connected ..");
            stmt = c.createStatement();   
            CreateSql = "Create Table Test(id int primary key, name varchar, address text) ";
            stmt.executeUpdate(CreateSql);
            stmt.close();
            c.close();
        }

        catch (Exception e) {
            System.err.println( e.getClass().getName()+": "+ e.getMessage() );
            System.exit(0);
        }

        System.out.println("Table Created successfully");
    }
}

...which compiled successfully but when I go to run it, with postgresql-42.2.9.jar stored in path C:\PostgreSQL\libs, like as follows:

java -cp C:\PostgreSQL\libs . CreateTable

...the command line returns:

Error: Could not find or load main class .

Some of this is my limited knowledge of Java.  My question then is, Where should the jdbc jar be located in order to run, and then how do I run all this at the command line?  Thank you for any help.

On Sun, 2020-01-19 at 19:24 -0500, CR20 wrote:
> ...which compiled successfully but when I go to run it, with postgresql-42.2.9.jar stored in path C:\PostgreSQL\libs,
likeas follows:
 
> 
> java -cp C:\PostgreSQL\libs . CreateTable
> 
> ...the command line returns:
> 
> Error: Could not find or load main class .
> 
> Some of this is my limited knowledge of Java.

Indeed.  You have to treat the JAR file as if it were a directory,
that is, put the file itself on the class path:

  java -cp C:\PostgreSQL\libs\postgresql-42.2.9.jar;. CreateTable

Yours,
Laurenz Albe
-- 
Cybertec | https://www.cybertec-postgresql.com