BigDecimal variable padded with random numbers in JDBC Insert

Question

Consider SQL statement INSERT INTO table (field) VALUES (-0.11111111) with field Oracle type NUMBER.

When the value to be inserted is of type float or double, you get the exact value in field, i.e. -0.11111111.

But when the value to be inserted is of type BigDecimal, you get the value padded with random numbers, i.e. 0.1111111099999999990428634077943570446223.

Why?

Java states that "BigDecimal is an immutable, arbitrary-precision signed decimal numbers."

The code is:

String sql = "INSERT INTO pat_statistics (file_key,test_number,rqw)"
    + " VALUES (3778, 100, " + new BigDecimal(-0.11111111) + ")";
Class.forName(driver);
Connection conn = DriverManager.getConnection(url, user, pwd);
Statement st = conn.createStatement();
int n = st.executeUpdate(sql);

The DB is Oracle.

Answer 1

For a literal value you should always use the BigDecimal constructor taking a string argument. See the documentation of the BigDecimal(double) constructor for details.