UPDATE with prepared parameter does not update rows

Detail name	Value
Changelog Number	29170
Type	Bug
Status	Resolved
Affected Versions	Exasol 7.1.0, Exasol 8.0.0, Exasol 8.29.0, Exasol 2025.1.0, Exasol 2025.2.0
Fix Versions	Exasol 2026.1.0, Exasol 2025.2.1, Exasol 2025.1.10
Resolution Date	2026-02-18

Description

Under specific conditions, an UPDATE statement with prepared parameter may cause an Internal Server Error.
Conditions:

• The statement is an UPDATE statement.
• The statement contains a subquery in the WHERE condition.
• The WHERE condition contains also another predicate with a prepared parameter.
• The client executes the statement with more than one tuple.

Example:

stmt.execute("CREATE OR REPLACE TABLE T(x INT, y int)");
stmt.execute("INSERT INTO T VALUES (1,1), (2,2), (3,3)");

PreparedStatement prepStmt = conn.prepareStatement(
    "UPDATE T
   SET x = (SELECT COUNT(*)+1 FROM DUAL)
   WHERE x = (SELECT COUNT(*) FROM DUAL) AND x = ?;");
prepStmt.setInt(1, 1);
prepStmt.addBatch();
prepStmt.setInt(1, 2);
prepStmt.addBatch();

// Expected: Updated rows
// Observed: Internal Server Error
prepStmt.executeBatch();

Workaround

Execute the query with a single batch/tuple.

Fix

The UPDATE works as intended.