How to detect string truncation

Question

I use jTDS 1.2.6 to connect Adaptive Server Enterprise/15.7.0. When a prepared statement insert rows in a table with a VARCHAR(16) column, the strings are silently truncated. The insertion is successful, no warning and no DataTruncation exception is raised whereas the encoded is string is truncated to 16 octet.

How could I detect the string truncation ?

Answer 1

Adaptive Server truncates entries to the specified column length without warning or error, unless you set string_rtruncation on. See the Reference Manual: Commands.

MSSQL always detect truncation of strings and the option STRING_RTRUNCATION does not exist. Here is an excerpt of jTDS SAfeTest.testDataTruncException()

Statement stmt = con.createStatement();
if (!con.getMetaData().getDatabaseProductName().toLowerCase().startsWith("microsoft")) {
    // By default Sybase will silently truncate strings,
    // set an option to ensure that an exception is thrown.
     stmt.execute("SET STRING_RTRUNCATION ON");
}