LIKE does not match empty strings when used with a prepared statement

• Key: DERBY-1231
• Type: Bug
• Status: Closed
• Resolution: Fixed
• Priority: Major
• Assignee: Bernt M. Johnsen
• Reporter: Dyre Tjeldvoll
• Component/s: JDBC, SQL
• Affects Version/s: 10.1.2.1, 10.1.3.1, 10.2.1.6, 10.3.1.4
• Fix Version/s: 10.2.2.0, 10.3.1.4

Description

LIKE should give true for two 0-length strings. See SQL 2003 Ch. 8.5
General Rules 3)c)i)

The query SELECT * FROM t WHERE v like ''

appears to give me all rows where v is an empty
string, as expected.

But a prepared statement

SELECT * FROM t WHERE v like ?, with setString(1, "")

always returns an empty result set. See attached repro for the full example.