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How to get the insert ID in JDBC?

Posted by: admin November 2, 2017 Leave a comment

Questions:

I want to INSERT a record in a database (which is Microsoft SQL Server in my case) using JDBC in Java. At the same time, I want to obtain the insert ID. How can I achieve this using JDBC API?

Answers:

If it is an auto generated key, then you can use Statement#getGeneratedKeys() for this. You need to call it on the same Statement as the one being used for the INSERT. You first need to create the statement using Statement.RETURN_GENERATED_KEYS to notify the JDBC driver to return the keys.

Here’s a basic example:

public void create(User user) throws SQLException {
    try (
        Connection connection = dataSource.getConnection();
        PreparedStatement statement = connection.prepareStatement(SQL_INSERT,
                                      Statement.RETURN_GENERATED_KEYS);
    ) {
        statement.setString(1, user.getName());
        statement.setString(2, user.getPassword());
        statement.setString(3, user.getEmail());
        // ...

        int affectedRows = statement.executeUpdate();

        if (affectedRows == 0) {
            throw new SQLException("Creating user failed, no rows affected.");
        }

        try (ResultSet generatedKeys = statement.getGeneratedKeys()) {
            if (generatedKeys.next()) {
                user.setId(generatedKeys.getLong(1));
            }
            else {
                throw new SQLException("Creating user failed, no ID obtained.");
            }
        }
    }
}

Note that you’re dependent on the JDBC driver whether it works. Currently, most of the last versions will do, but if I am correct, Oracle JDBC driver is still somewhat troublesome with this. MySQL and DB2 already supported it for ages. PostgreSQL started to support it short ago. No wording about MSSQL as I’ve never used it.

For Oracle, you can invoke a CallableStatement with a RETURNING clause or a SELECT CURRVAL(sequencename) (or whatever DB-specific syntax to do so) directly after the INSERT in the same transaction to obtain the last generated key. See also this answer.

Questions:
Answers:

I’m hitting Microsoft SQL Server 2008 R2 from a single-threaded JDBC-based application and pulling back the last ID without using the RETURN_GENERATED_KEYS property or any PreparedStatement. Looks something like this:

private int insertQueryReturnInt(String SQLQy) {
    ResultSet generatedKeys = null;
    int generatedKey = -1;

    try {
        Statement statement = conn.createStatement();
        statement.execute(SQLQy);
    } catch (Exception e) {
        errorDescription = "Failed to insert SQL query: " + SQLQy + "( " + e.toString() + ")";
        return -1;
    }

    try {
        generatedKey = Integer.parseInt(readOneValue("SELECT @@IDENTITY"));
    } catch (Exception e) {
        errorDescription = "Failed to get ID of just-inserted SQL query: " + SQLQy + "( " + e.toString() + ")";
        return -1;
    }

    return generatedKey;
} 

This blog post nicely isolates three main SQL Server “last ID” options:
http://msjawahar.wordpress.com/2008/01/25/how-to-find-the-last-identity-value-inserted-in-the-sql-server/ – haven’t needed the other two yet.

Questions:
Answers:
  1. Create Generated Column

    String generatedColumns[] = { "ID" };
    
  2. Pass this geneated Column to your statement

    PreparedStatement stmtInsert = conn.prepareStatement(insertSQL, generatedColumns);
    
  3. Use ResultSet object to fetch the GeneratedKeys on Statement

    ResultSet rs = stmtInsert.getGeneratedKeys();
    
    if (rs.next()) {
        long id = rs.getLong(1);
        System.out.println("Inserted ID -" + id); // display inserted record
    }
    
Questions:
Answers:

According to ‘Unsupported feature’ error with using Statement.RETURN_GENERATED_KEYS, Try this:

    String[] returnId = { "BATCHID" };
    String sql = "INSERT INTO BATCH (BATCHNAME) VALUES ('aaaaaaa')";
    PreparedStatement statement = connection
            .prepareStatement(sql, returnId);
    int affectedRows = statement.executeUpdate();

    if (affectedRows == 0) {
        throw new SQLException("Creating user failed, no rows affected.");
    }

    try (ResultSet rs = statement.getGeneratedKeys()) {
        if (rs.next()) {
            System.out.println(rs.getInt(1));
        }
        rs.close();

    }

Where BRANCHID is the auto generated id

Questions:
Answers:

I’m using SQLServer 2008, but I have a development limitation: I cannot use a new driver for it, I have to use “com.microsoft.jdbc.sqlserver.SQLServerDriver” (I cannot use “com.microsoft.sqlserver.jdbc.SQLServerDriver”).

That’s why the solution conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS) threw a java.lang.AbstractMethodError for me.
In this situation, a possible solution I found is the old one suggested by Microsoft:
How To Retrieve @@IDENTITY Value Using JDBC

import java.sql.*; 
import java.io.*; 

public class IdentitySample
{
    public static void main(String args[])
    {
        try
        {
            String URL = "jdbc:microsoft:sqlserver://yourServer:1433;databasename=pubs";
            String userName = "yourUser";
            String password = "yourPassword";

            System.out.println( "Trying to connect to: " + URL); 

            //Register JDBC Driver
            Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();

            //Connect to SQL Server
            Connection con = null;
            con = DriverManager.getConnection(URL,userName,password);
            System.out.println("Successfully connected to server"); 

            //Create statement and Execute using either a stored procecure or batch statement
            CallableStatement callstmt = null;

            callstmt = con.prepareCall("INSERT INTO myIdentTable (col2) VALUES (?);SELECT @@IDENTITY");
            callstmt.setString(1, "testInputBatch");
            System.out.println("Batch statement successfully executed"); 
            callstmt.execute();

            int iUpdCount = callstmt.getUpdateCount();
            boolean bMoreResults = true;
            ResultSet rs = null;
            int myIdentVal = -1; //to store the @@IDENTITY

            //While there are still more results or update counts
            //available, continue processing resultsets
            while (bMoreResults || iUpdCount!=-1)
            {           
                //NOTE: in order for output parameters to be available,
                //all resultsets must be processed

                rs = callstmt.getResultSet();                   

                //if rs is not null, we know we can get the results from the SELECT @@IDENTITY
                if (rs != null)
                {
                    rs.next();
                    myIdentVal = rs.getInt(1);
                }                   

                //Do something with the results here (not shown)

                //get the next resultset, if there is one
                //this call also implicitly closes the previously obtained ResultSet
                bMoreResults = callstmt.getMoreResults();
                iUpdCount = callstmt.getUpdateCount();
            }

            System.out.println( "@@IDENTITY is: " + myIdentVal);        

            //Close statement and connection 
            callstmt.close();
            con.close();
        }
        catch (Exception ex)
        {
            ex.printStackTrace();
        }

        try
        {
            System.out.println("Press any key to quit...");
            System.in.read();
        }
        catch (Exception e)
        {
        }
    }
}

This solution worked for me!

I hope this helps!

Questions:
Answers:
Connection cn = DriverManager.getConnection("Host","user","pass");
Statement st = cn.createStatement("Ur Requet Sql");
int ret  = st.execute();