I have created a set of SQL queries that modify a database, and now I want to test them.
How can I create a local and temporary PostgreSQL database to test my queries. I'm working in Java.
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2FWIW, I wouldn't do that part in Java. The tutorial discusses creating a DB, tables, etc.Dave Newton– Dave Newton2011-10-30 13:49:34 +00:00Commented Oct 30, 2011 at 13:49
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1And after setting up the database I'm sure you want to know how to connect to that database inn Java. The PostgreSQL JDBC Docs will tell you.A.H.– A.H.2011-10-30 14:20:49 +00:00Commented Oct 30, 2011 at 14:20
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4 Answers
You CAN create and drop PostgreSQL db's via Java using the Statement object.
Example:
Connection c = DriverManager.getConnection("jdbc:postgresql://localhost:5432/", "username", "password");
Statement statement = c.createStatement();
statement.executeUpdate("DROP DATABASE mydb");
See the following link for a good starting point:
http://www.jvmhost.com/articles/create-drop-databases-dynamically-java-jsp-code
2 Comments
Bằng Rikimaru
This one does not work as Java JDBC throws exception right after DriverManager.getConnection(...) because if database name is not specified it will use the username as default database. jdbc.postgresql.org/documentation/head/connect.html
Yuri
This is clearly wrong since it requires a database named
user to exist.Creating a database is simple enough once your database cluster is in place.
Connect to the maintenance database postgres (installed by default) and issue
CREATE DATABASE testdb;
The database will be created and you can connect to it now. Of course you need to have the necessary privileges to create a database.
answered Oct 30, 2011 at 14:24
Erwin Brandstetter
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You can see her how to create database Hope this help
- What you do is connect to localhost
- create an sql "create database your_db"
- execute
http://www.tutorialspoint.com/jdbc/jdbc-create-database.htm
You must connect first to the localhost
//STEP 1. Import required packages
import java.sql.*;
public class JDBCExample {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/";
// Database credentials
static final String USER = "username";
static final String PASS = "password";
public static void main(String[] args) {
Connection conn = null;
Statement stmt = null;
try{
//STEP 2: Register JDBC driver
Class.forName("com.mysql.jdbc.Driver");
//STEP 3: Open a connection
System.out.println("Connecting to database...");
conn = DriverManager.getConnection(DB_URL, USER, PASS);
//STEP 4: Execute a query
System.out.println("Creating database...");
stmt = conn.createStatement();
String sql = "CREATE DATABASE STUDENTS";
stmt.executeUpdate(sql);
System.out.println("Database created successfully...");
}catch(SQLException se){
//Handle errors for JDBC
se.printStackTrace();
}catch(Exception e){
//Handle errors for Class.forName
e.printStackTrace();
}finally{
//finally block used to close resources
try{
if(stmt!=null)
stmt.close();
}catch(SQLException se2){
}// nothing we can do
try{
if(conn!=null)
conn.close();
}catch(SQLException se){
se.printStackTrace();
}//end finally try
}//end try
System.out.println("Goodbye!");
}//end main
}//end JDBCExample
Your question is little bit wrong,with Java code you cannot create a database,you can just connect to a database.
First of all you need to create a database in PgAdminIII.
Here is the code which will help you to create table in postgresql database through JAVA
package database;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Level;
import java.util.logging.Logger;
public class Database {
public static void main(String args[]) {
try {
Connection c = null;
Statement stmt = null;
try {
Class.forName("org.postgresql.Driver");
c = DriverManager.getConnection("jdbc:postgresql://localhost:5432/kanwar","postgres", "osm");
} catch (Exception e) {
e.printStackTrace();
System.err.println(e.getClass().getName()+": "+e.getMessage());
System.exit(0);
}
System.out.println("Opened database successfully");
try {
stmt = c.createStatement();
} catch (SQLException ex) {
Logger.getLogger(Database.class.getName()).log(Level.SEVERE, null, ex);
}
String sql = "CREATE TABLE MY_TABLE "+
"(ID INT NOT NULL,"
+ "NAME TEXT NOT NULL,"
+ "AGE INT NOT NULL)";
stmt.executeUpdate(sql);
stmt.close();
c.close();
} catch (SQLException ex) {
Logger.getLogger(Database.class.getName()).log(Level.SEVERE, null, ex);
}
catch(Exception e)
{
System.err.println( e.getClass().getName()+": "+ e.getMessage() );
System.exit(0);
}
System.out.println("Table Created Successfully");
}
}
For complete reference:http://kodingpoint.blogspot.in/2014/01/java-postgresql-connectivity-example.html
