PLSQL JDBC: How to get last row ID?

Question

What's PLSQL (Oracle) equivalent of this SQL server snippet?

BEGIN TRAN
INSERT INTO mytable(content) VALUES ("test") -- assume there's an ID column that is autoincrement
SELECT @@IDENTITY
COMMIT TRAN

In C#, you can call myCommand.ExecuteScalar() to retrieve the ID of the new row.

How can I insert a new row in Oracle, and have JDBC get a copy of the new id?

EDIT: BalusC provided a very good starting point. For some reason JDBC doesn't like named parameter binding. This gives "Incorrectly set or registered parameters" SQLException. Why is this happening?

        OracleConnection conn = getAppConnection();
        String q = "BEGIN INSERT INTO tb (id) values (claim_seq.nextval) returning id into :newId; end;" ;
        CallableStatement cs = (OracleCallableStatement) conn.prepareCall(q);
        cs.registerOutParameter("newId", OracleTypes.NUMBER);
        cs.execute();
        int newId = cs.getInt("newId");

Solution 1

Normally you would use Statement#getGeneratedKeys() for this (see also this answer for an example), but this is as far (still) not supported by the Oracle JDBC driver.

Your best bet is to either make use of CallableStatement with a RETURNING clause:

String sql = "BEGIN INSERT INTO mytable(id, content) VALUES (seq_mytable.NEXTVAL(), ?) RETURNING id INTO ?; END;";

Connection connection = null;
CallableStatement statement = null;

try {
    connection = database.getConnection();
    statement = connection.prepareCall(sql);
    statement.setString(1, "test");
    statement.registerOutParameter(2, Types.NUMERIC);
    statement.execute();
    int id = statement.getInt(2);
    // ...

Or fire SELECT sequencename.CURRVAL after INSERT in the same transaction:

String sql_insert = "INSERT INTO mytable(content) VALUES (?)";
String sql_currval = "SELECT seq_mytable.CURRVAL FROM dual";

Connection connection = null;
PreparedStatement statement = null;
Statement currvalStatement = null;
ResultSet currvalResultSet = null;

try {
    connection = database.getConnection();
    connection.setAutoCommit(false);
    statement = connection.prepareStatement(sql_insert);
    statement.setString(1, "test");
    statement.executeUpdate();
    currvalStatement = connection.createStatement();
    currvalResultSet = currvalStatement.executeQuery(sql_currval);
    if (currvalResultSet.next()) {
        int id = currvalResultSet.getInt(1);
    }
    connection.commit();
    // ...

Solution 2

You can use Oracle's returning clause.

insert into mytable(content) values ('test') returning your_id into :var;

Check out this link for a code sample. You need Oracle 10g or later, and a new version of JDBC driver.

Solution 3

You can use getGeneratedKeys(), By explicitly selecting key field. Here is a snippet:

    // change the string to your connection string
    Connection connection = DriverManager.getConnection("connection string");

    // assume that the field "id" is PK, and PK-trigger exists 
    String sql = "insert into my_table(id) values (default)";
    // you can select key field by field index
    int[] colIdxes = { 1 };
    // or by field name
    String[] colNames = { "id" };

    // Java 1.7 syntax; try-finally for older versions
    try (PreparedStatement preparedStatement = connection.prepareStatement(sql, colNames))
    {
        // note: oracle JDBC driver do not support auto-generated key feature with batch update
        //          // insert 5 rows
        //          for (int i = 0; i < 5; i++)
        //          {
        //              preparedStatement.addBatch();
        //          }
        //          
        //          int[] batch = preparedStatement.executeBatch();
        preparedStatement.executeUpdate();

        // get generated keys
        try (ResultSet resultSet = preparedStatement.getGeneratedKeys())
        {
            while (resultSet.next())
            {
                // assume that the key's type is BIGINT
                long id = resultSet.getLong(1);
                assertTrue(id != 0);

                System.out.println(id);
            }
        }
    }

refer for details: http://docs.oracle.com/cd/E16655_01/java.121/e17657/jdbcvers.htm#CHDEGDHJ

Comments

[Patrick Marchand]

Do you mean "SELECT seq_mytable.CURRVAL from dual" instead of "SELECT CURRVAL(seq_mytable)"?

[BalusC]

@Patrick: Oh drat, I had PostgreSQL SQL syntax in mind, I'll update (previously, PostgreSQL used to have the same problem of not supporting Statement#getGeneratedKeys() so that the same "workaround" was necessary, but since about a year ago they finally fixed their JDBC driver to support it).

[Karthik Rao]

Hi BalusC, thanks for the help. Can you take a look at my edit see if you can solve that other mystery?

[BalusC]

You need to specify the placeholder index, not the column name. Replace "newId" by 2 in registerOutParameter().

[Karthik Rao]

In practice, I have a long insert statement with 15-some parameters, which I prefer having named binding if I could. JDBC will complain about having mixed binding if I use question mark. Do I must go with ordinal binding when out-parameter is used?

[BalusC]

For named binding, use an ORM like Hibernate/JPA. Basic JDBC doesn't support it.

[Subramanian]

I believe there is nothing incorrect with the JDBC specification from Oracle Driver's perspective. The prepareStatement call needs to be told to return auto-generated keys like this. conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);

[BalusC]

@Subramanian: So it has changed recently? So the example in the linked answer works for Oracle now? Note that both answers are posted 2 years ago.

[Ach J]

This works as long as the insert statement has up to 7 parameters, when there are more than 7 parameters an ArrayIndexOutofBound exception is thrown. Looks like a fault with the oracle jdbc driver. #Oracle_11g_R2. Answer from BalusC is better because of this reason.