should be it

external/duckdb/test/sql/constraints/unique/test_unique.test

@@ -0,0 +1,90 @@
+# name: test/sql/constraints/unique/test_unique.test
+# description: Single UNIQUE constraint
+# group: [unique]
+
+statement ok
+SET default_null_order='nulls_first';
+
+statement ok
+CREATE TABLE integers(i INTEGER UNIQUE, j INTEGER)
+
+# insert unique values
+statement ok
+INSERT INTO integers VALUES (3, 4), (2, 5)
+
+query II
+SELECT * FROM integers
+----
+3	4
+2	5
+
+# insert a duplicate value as part of a chain of values, this should fail
+statement error
+INSERT INTO integers VALUES (6, 6), (3, 4);
+----
+
+statement ok
+INSERT INTO integers VALUES (NULL, 6), (NULL, 7)
+
+# but if we try to replace them like this it's going to fail
+statement error
+UPDATE integers SET i=77 WHERE i IS NULL
+----
+
+query II
+SELECT * FROM integers ORDER BY i, j
+----
+NULL	6
+NULL	7
+2	5
+3	4
+
+# we can replace them like this though
+statement ok
+UPDATE integers SET i=77 WHERE i IS NULL AND j=6
+
+query II
+SELECT * FROM integers ORDER BY i, j
+----
+NULL	7
+2	5
+3	4
+77	6
+
+statement ok
+INSERT INTO integers VALUES (NULL, 6), (NULL, 7)
+
+statement ok
+INSERT INTO integers VALUES (NULL, 6), (NULL, 7)
+
+statement ok
+INSERT INTO integers VALUES (NULL, 6), (NULL, 7)
+
+statement ok
+INSERT INTO integers VALUES (NULL, 6), (NULL, 7)
+
+statement ok
+INSERT INTO integers VALUES (NULL, 6), (NULL, 7)
+
+statement ok
+INSERT INTO integers VALUES (NULL, 6), (NULL, 7)
+
+statement ok
+INSERT INTO integers VALUES (NULL, 6), (NULL, 7)
+
+statement ok
+INSERT INTO integers VALUES (NULL, 6), (NULL, 7)
+
+statement ok
+INSERT INTO integers VALUES (NULL, 6), (NULL, 7)
+
+statement ok
+INSERT INTO integers VALUES (NULL, 6), (NULL, 7)
+
+statement error
+INSERT INTO integers VALUES (NULL, 6), (3, 7)
+----
+
+statement ok
+DROP TABLE integers
+