Multiple Insert Query in Oracle - java

I had requirement to perform two insert queries in two different tables.
I am using Oracle/Java Combination.
What are the options available in this case?


If you're trying to insert the same data into two separate tables you can use a multitable insert like this:
insert all
into table1(a, b)
into table2(a, b)
select 1 a, 2 b from dual;


The most straightforward method is to do two inserts sequentially using the same connection. Assuming that part of your point is that you want the two inserts to occur in the same transaction, then make sure you have disabled autocommit on the connection, and explicitly commit after the second insert.
Another option would be to write an Oracle stored procedure that does the inserts, and call it from Java with a PreparedStatement.


Sample from devdaily.
package com.devdaily.sqlprocessortests;
import java.sql.*;
public class BasicJDBCDemo
{
Connection conn;
public static void main(String[] args)
{
new BasicJDBCDemo();
}
public BasicJDBCDemo()
{
try
{
Class.forName("com.mysql.jdbc.Driver").newInstance();
String url = "jdbc:mysql://localhost/coffeebreak";
conn = DriverManager.getConnection(url, "username", "password");
doTests();
conn.close();
}
catch (ClassNotFoundException ex) {System.err.println(ex.getMessage());}
catch (IllegalAccessException ex) {System.err.println(ex.getMessage());}
catch (InstantiationException ex) {System.err.println(ex.getMessage());}
catch (SQLException ex) {System.err.println(ex.getMessage());}
}
private void doTests()
{
doSelectTest();
doInsertTest(); doSelectTest();
doUpdateTest(); doSelectTest();
doDeleteTest(); doSelectTest();
}
private void doSelectTest()
{
System.out.println("[OUTPUT FROM SELECT]");
String query = "SELECT COF_NAME, PRICE FROM COFFEES";
try
{
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery(query);
while (rs.next())
{
String s = rs.getString("COF_NAME");
float n = rs.getFloat("PRICE");
System.out.println(s + " " + n);
}
}
catch (SQLException ex)
{
System.err.println(ex.getMessage());
}
}
private void doInsertTest()
{
System.out.print("\n[Performing INSERT] ... ");
try
{
Statement st = conn.createStatement();
st.executeUpdate("INSERT INTO COFFEES " +
"VALUES ('BREAKFAST BLEND', 200, 7.99, 0, 0)");
}
catch (SQLException ex)
{
System.err.println(ex.getMessage());
}
}
private void doUpdateTest()
{
System.out.print("\n[Performing UPDATE] ... ");
try
{
Statement st = conn.createStatement();
st.executeUpdate("UPDATE COFFEES SET PRICE=4.99 WHERE COF_NAME='BREAKFAST BLEND'");
}
catch (SQLException ex)
{
System.err.println(ex.getMessage());
}
}
private void doDeleteTest()
{
System.out.print("\n[Performing DELETE] ... ");
try
{
Statement st = conn.createStatement();
st.executeUpdate("DELETE FROM COFFEES WHERE COF_NAME='BREAKFAST BLEND'");
}
catch (SQLException ex)
{
System.err.println(ex.getMessage());
}
}
}


You can check with StoredProcedures and execute with PreparedStatement in JDBC api. That intern will return you two resultSets , which you can get with a method getMoreResults(). You can then process the resultsets separately.

Related

How to Close Statements and Connection in This Method

How to Close Statements and Connection in This Method
public static ResultSet getData (String query){
try {
Connection con = ConnectionProvider.connect();
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(query);
return rs;
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e);
System.out.println(e);
return null;
}

You need to close connections in finally block:
try {
...
}
catch {
...
}
finally {
try { st.close(); } catch (Exception e) { /* Ignored */ }
try { con.close(); } catch (Exception e) { /* Ignored */ }
}
In Java 7 and higher you can define all your connections and statements as a part of try block:
try(Connection con = ConnectionProvider.connect();
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(query);
) {
// Statements
}
catch(....){}

One should use try-with-resources to automatically close all.
Then there is the p
public static void processData (String query, Consumer<ResultSet> processor){
try (Connection con = ConnectionProvider.connect();
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(query)) {
processor.accept(rs);
} catch (SQLException e) {
JOptionPane.showMessageDialog(null, e);
System.getLogger(getClass().getName()).log(Level.Error, e);
}
}
processData("SELECT * FROM USERS", rs -> System.out.println(rs.getString("NAME")));
Or
public static <T> List<T> getData (String query, UnaryOperator<ResultSet, T> convert){
try (Connection con = ConnectionProvider.connect();
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(query)) {
List<T> result = new ArrayList<>();
while (rs.next()) {
result.add(convert.apply(rs));
}
return result;
} catch (SQLException e) {
System.getLogger(getClass().getName()).log(Level.Error, e);
throw new IllegalArgumentException("Error in " + query, e);
}
}
Then there is the danger with this function, that users will compose query strings like:
String query = "SELECT * FROM USERS WHERE NAME = '" + name + "'";
Which does not escape the apostrophes like in d'Alembert. It opens the gates to SQL injection, a large security breach. One needs a PreparedStatement, and then can use type-safe parameters.
As with try-with-resources the code already is reduced (no explicit closes), you should drop this kind of function. But almost most programmers make this mistake.

SQL query in Java does not work, no error is appearing but the data isn't appearung in DB

I try to insert a row to the database, but it doesn't appear in the table after running:
This is the main class:
public class Tester {
public static void main(String[] args) {
CouponsDbDao coupDbDao = new CouponsDbDao();
Coupon coupon = new Coupon(1, 0, Category.Food, null, null, null, null, 25, 0, null);
coupDbDao.addCoupon(coupon);
}
}
And this is the method:
public class CouponsDbDao {
public void addCoupon(Coupon coupon) {
try {
Connection connection = JdbcUtils.getConnection();
String sqlStatement = "insert into coupons (COMPANY_ID,CATEGORY_ID,TITLE,DESCRIPTION,START_DATE,END_DATE,AMOUNT,PRICE,IMAGE) values(?,?,?,?,?,?,?,?,?)";
PreparedStatement statement = connection.prepareStatement(sqlStatement);
statement.setInt(1, coupon.getCompanyId());
statement.setObject(2, coupon.getCategory());
statement.setString(3, coupon.getTitle());
statement.setString(4, coupon.getDescription());
statement.setDate(5, coupon.getStartDate());
statement.setDate(6, coupon.getEndDate());
statement.setInt(7, coupon.getAmount());
statement.setDouble(8, coupon.getPrice());
statement.setString(9, coupon.getImage());
} catch (Exception e) {
e.printStackTrace();
}
}

You need to execute the statement after setting values. Additionally, you need to close the connection created, the preparedstatement etc in a finally block.
public class CouponsDbDao {
Connection connection = null;
PreparedStatement statement = null;
public void addCoupon(Coupon coupon) {
try {
connection= JdbcUtils.getConnection();
String sqlStatement = "insert into coupons (COMPANY_ID,CATEGORY_ID,TITLE,DESCRIPTION,START_DATE,END_DATE,AMOUNT,PRICE,IMAGE) values(?,?,?,?,?,?,?,?,?)";
statement = connection.prepareStatement(sqlStatement);
statement.setInt(1, coupon.getCompanyId());
statement.setObject(2, coupon.getCategory());
statement.setString(3, coupon.getTitle());
statement.setString(4, coupon.getDescription());
statement.setDate(5, coupon.getStartDate());
statement.setDate(6, coupon.getEndDate());
statement.setInt(7, coupon.getAmount());
statement.setDouble(8, coupon.getPrice());
statement.setString(9, coupon.getImage());
statement.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
}
finally{
if (statement != null) {
try {
statement.close();
} catch (SQLException e) { /* print here */}
}
if (connection != null) {
try {
connection.close();
} catch (SQLException e) { /* print here */}
}
}
}

As told by others you need to call executeUpdate to really perform the query:
Executes the SQL statement in this PreparedStatement object, which must be an SQL Data Manipulation Language (DML) statement, such as INSERT, UPDATE or DELETE
I suggest you also to use the try with resources:
The try-with-resources statement is a try statement that declares one or more resources. A resource is an object that must be closed after the program is finished with it. The try-with-resources statement ensures that each resource is closed at the end of the statement. Any object that implements java.lang.AutoCloseable, which includes all objects which implement java.io.Closeable, can be used as a resource.
This has been introduced in java 7 and let you eliminate the finally boiler plate code as follow:
// ORIGINAL CODE
Connection connection = ...
try {
connection = JdbcUtils.getConnection();
...
statement.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
} finally {
if (statement != null) {
try {
statement.close();
} catch (SQLException e) { /* print here */}
}
if (connection != null) {
try {
connection.close();
} catch (SQLException e) { /* print here */}
}
}
becomes:
// USING try with resources
try (Connection connection = JdbcUtils.getConnection()) {
...
statement.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
} // NO need of the finally block because connection is AutoCloseable

You need to execute update for statement, like:
statement.executeUpdate();

NetBeans and SQLite table communication issue?

Hi I’m trying to connect to and SQLite table in java and it only outputs data from one method in the compiler output window code is below working method it commented to show which one is printing out the data please could you help.
//working methord which outputs data
#Override
public String getReplyTimestamp(int RPLYID) {
try {
Class.forName("org.sqlite.JDBC");
Connection conn = DriverManager.getConnection("jdbc:sqlite:C:\\Users\\Matt\\Documents\\message.sqlite");
Statement stmt = conn.createStatement();
String query = "SELECT * FROM MSG"; //Change message to relevent declaration
ResultSet rs = stmt.executeQuery(query);
while (rs.next()) {
System.out.println(rs.getString("MSG")+" "+rs.getString("URL"));
}
conn.close();
} catch (SQLException ex) {
Logger.getLogger(DBAccessImpl.class.getName()).log(Level.SEVERE, null, ex);
} catch (ClassNotFoundException ex) {
Logger.getLogger(DBAccessImpl.class.getName()).log(Level.SEVERE, null, ex);
}
return "getReplyTimestamp";
}
//Methoed which does not print
#Override
public String getReply(int RPLYID) {
try {
Class.forName("org.sqlite.JDBC");
Connection conn = DriverManager.getConnection("jdbc:sqlite:C:\\Users\\Matt\\Documents\\message.sqlite");
Statement stmt = conn.createStatement();
String query = "SELECT * FROM RPLY"; //Change message to relevent declaration
ResultSet rs = stmt.executeQuery(query);
while (rs.next()) {
System.out.println(rs.getString("RPLY")+" "+rs.getString("TSTAMP"));
}
conn.close();
} catch (SQLException ex) {
Logger.getLogger(DBAccessImpl.class.getName()).log(Level.SEVERE, null, ex);
} catch (ClassNotFoundException ex) {
Logger.getLogger(DBAccessImpl.class.getName()).log(Level.SEVERE, null, ex);
}
return "getReply";
}

combination of Oracle database and in-memory database in java program

I am going to enhance the performance of my program. For this purpose I am going to implement some parts of my program to be done in memory instead of database. I dont know which one is better in this regards, in-memory database or normal java data structure.For in-memory database I considered Tentimes from oracle and H2. So another question would be which solution is better for around 100 million records of data on single machine for single user? Also another question would be is the old way of database connection works fine in this way? Here is the connection that I used for oracle, What is the appropriate Driver for this purpose.
public static Connection getConnection(){
//If instance has not been created yet, create it
if(DatabaseManager.connection == null){
initConnection();
}
return DatabaseManager.connection;
}
//Gets JDBC connection instance
private static void initConnection(){
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
String connectionUrl = "jdbc:oracle:thin:#localhost:1521:" + dbName;
DatabaseManager.connection =
DriverManager.getConnection(connectionUrl,"****","****");
}
catch (ClassNotFoundException e){
System.out.println("Oracle driver is not loaded!");
System.exit(0);
}
catch (SQLException e){
System.out.println(e.getMessage());
System.exit(0);
}
catch (Exception e){
}
}
public static ResultSet executeQuery(String SQL) throws SQLException
{
CachedRowSetImpl crs = new CachedRowSetImpl();
ResultSet rset = null ;
Statement st = null;
try {
st = DatabaseManager.getConnection().createStatement();
rset = st.executeQuery(SQL);
crs.populate(rset);
}
catch (SQLException e) {
System.out.println(e.getMessage());
System.exit(0);
}finally{
rset.close();
st.close();
}
return crs;
}
public static void executeUpdate(String SQL)
{
try {
Statement st = DatabaseManager.getConnection().createStatement();
st.executeUpdate(SQL);
// st.close();
}
catch (SQLException e) {
System.out.println(e.getMessage());
System.exit(0);
}
}
Regards.

unable to drop table in HSQLDB

I am unable to drop table with default user SA(or any user for that matter) in HSQLDB even though I can create table and read them without problem, please see my code below, what's wrong?
On the other hand, If I use a third party SQL client(eg. squirrel), I can login and drop table without problem even when user is empty.
public static void main(String[]args){
try {
DBManager.executeUpdate("drop table mytable");
} catch (SQLException ex) {
ex.printStackTrace();
}
}
public static Connection getConnection(){
Connection c =null;
try {
c = DriverManager.getConnection("jdbc:hsqldb:file:e:\\xxx_db\\xxx", "SA", "");
} catch (SQLException ex) {
ex.printStackTrace();
}
return c;
}
public static int executeUpdate(String s) throws SQLException {
Connection con = getConnection();
try{
return con.createStatement().executeUpdate(s);
}
finally{
if(con!=null)try {
con.close();
} catch (SQLException ex) {
Logger.getLogger(DBManager.class.getName()).log(Level.SEVERE, null, ex);
}
}
}

It turns out I need to do an explicit shutdown aftwards
DBManager.executeUpdate("shutdown");

Try committing after executing the DDL.

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