Data update

Task/Copy-a-string/DuckDB/copy-a-string.duckdb

@@ -0,0 +1,40 @@
+D create or replace table t as (select 'This is a string' as s);
+
+D from t;
+┌──────────────────┐
+│        s         │
+│     varchar      │
+├──────────────────┤
+│ This is a string │
+└──────────────────┘
+
+# Now make two copies.
+D create or replace table tt as (select s as s1, s as s2 from t);
+
+D from tt;
+┌──────────────────┬──────────────────┐
+│        s1        │        s2        │
+│     varchar      │     varchar      │
+├──────────────────┼──────────────────┤
+│ This is a string │ This is a string │
+└──────────────────┴──────────────────┘
+
+# Change s2 and then verify that s1 is unaltered
+D UPDATE tt SET s2 = s2[1];
+
+D from tt;
+┌──────────────────┬─────────┐
+│        s1        │   s2    │
+│     varchar      │ varchar │
+├──────────────────┼─────────┤
+│ This is a string │ T       │
+└──────────────────┴─────────┘
+
+# Check that s and s1 are also still equal
+D select s = s1 from t positional join tt;
+┌──────────┐
+│ (s = s1) │
+│ boolean  │
+├──────────┤
+│ true     │
+└──────────┘