should be it

external/duckdb/test/sql/alter/struct/add_col_nested_struct.test

@@ -0,0 +1,45 @@
+# name: test/sql/alter/struct/add_col_nested_struct.test
+# description: Test ALTER TABLE ADD COLUMN: add column to a struct nested
+# group: [struct]
+
+statement ok
+CREATE TABLE test(s STRUCT(s2 STRUCT(v1 INT, v2 INT)))
+
+statement ok
+INSERT INTO test VALUES (ROW(ROW(1, 1))), (ROW(ROW(2, 2)))
+
+# add a column to a nested struct
+statement ok
+ALTER TABLE test ADD COLUMN s.s2.k INTEGER
+
+query I
+SELECT * FROM test
+----
+{'s2': {'v1': 1, 'v2': 1, 'k': NULL}}
+{'s2': {'v1': 2, 'v2': 2, 'k': NULL}}
+
+# already exists
+statement error
+ALTER TABLE test ADD COLUMN s.s2.v1 VARCHAR
+----
+field already exists in struct s2
+
+# this just gets ignored
+statement ok
+ALTER TABLE test ADD COLUMN IF NOT EXISTS s.s2.v1 VARCHAR
+
+# we can add columns at all levels
+statement ok
+ALTER TABLE test ADD COLUMN s.i INTEGER DEFAULT 100
+
+query I
+SELECT * FROM test
+----
+{'s2': {'v1': 1, 'v2': 1, 'k': NULL}, 'i': 100}
+{'s2': {'v1': 2, 'v2': 2, 'k': NULL}, 'i': 100}
+
+statement error
+ALTER TABLE test ADD COLUMN s.s2.v1.x INTEGER
+----
+Binder Error: Column 'v1' is not a nested type, ADD COLUMN can only be used on nested types
+

external/duckdb/test/sql/alter/struct/add_col_struct.test

@@ -0,0 +1,79 @@
+# name: test/sql/alter/struct/add_col_struct.test
+# description: Test ALTER TABLE ADD COLUMN: add column to a struct
+# group: [struct]
+
+statement ok
+CREATE TABLE test(s STRUCT(i INTEGER, j INTEGER))
+
+statement ok
+INSERT INTO test VALUES (ROW(1, 1)), (ROW(2, 2))
+
+# add a column to a struct
+statement ok
+ALTER TABLE test ADD COLUMN s.k INTEGER
+
+query I
+SELECT * FROM test
+----
+{'i': 1, 'j': 1, 'k': NULL}
+{'i': 2, 'j': 2, 'k': NULL}
+
+# defaults
+statement ok
+ALTER TABLE test ADD COLUMN s.l INTEGER DEFAULT 42
+
+query I
+SELECT * FROM test
+----
+{'i': 1, 'j': 1, 'k': NULL, 'l': 42}
+{'i': 2, 'j': 2, 'k': NULL, 'l': 42}
+
+# this is transactional
+statement ok
+BEGIN
+
+statement ok
+ALTER TABLE test ADD COLUMN s.m INTEGER DEFAULT 42
+
+query I
+SELECT * FROM test
+----
+{'i': 1, 'j': 1, 'k': NULL, 'l': 42, 'm': 42}
+{'i': 2, 'j': 2, 'k': NULL, 'l': 42, 'm': 42}
+
+statement ok
+ROLLBACK
+
+query I
+SELECT * FROM test
+----
+{'i': 1, 'j': 1, 'k': NULL, 'l': 42}
+{'i': 2, 'j': 2, 'k': NULL, 'l': 42}
+
+# already exists
+statement error
+ALTER TABLE test ADD COLUMN s.i VARCHAR
+----
+field already exists in struct s
+
+# this just gets ignored
+statement ok
+ALTER TABLE test ADD COLUMN IF NOT EXISTS s.i VARCHAR
+
+query I
+SELECT * FROM test
+----
+{'i': 1, 'j': 1, 'k': NULL, 'l': 42}
+{'i': 2, 'j': 2, 'k': NULL, 'l': 42}
+
+# not a struct
+statement error
+ALTER TABLE test ADD COLUMN s.i.a INTEGER
+----
+Binder Error: Column 'i' is not a nested type, ADD COLUMN can only be used on nested types
+
+# nested column does not exist
+statement error
+ALTER TABLE test ADD COLUMN s.x.a INTEGER
+----
+does not exist

external/duckdb/test/sql/alter/struct/drop_col_nested_struct.test

@@ -0,0 +1,39 @@
+# name: test/sql/alter/struct/drop_col_nested_struct.test
+# description: Test ALTER TABLE DROP COLUMN: drop column from a nested struct
+# group: [struct]
+
+statement ok
+CREATE TABLE test(s STRUCT(i INT, s2 STRUCT(v1 INT, v2 INT)))
+
+statement ok
+INSERT INTO test VALUES (ROW(42, ROW(1, 1))), (ROW(84, ROW(2, 2)))
+
+# add a column to a nested struct
+statement ok
+ALTER TABLE test DROP s.s2.v1
+
+query I
+SELECT * FROM test
+----
+{'i': 42, 's2': {'v2': 1}}
+{'i': 84, 's2': {'v2': 2}}
+
+# does not exists
+statement error
+ALTER TABLE test DROP COLUMN s.s2.v1
+----
+does not exist
+
+# this just gets ignored
+statement ok
+ALTER TABLE test DROP COLUMN IF EXISTS s.s2.v1
+
+# we can drop the struct in its entirety
+statement ok
+ALTER TABLE test DROP COLUMN s.s2
+
+query I
+SELECT * FROM test
+----
+{'i': 42}
+{'i': 84}

external/duckdb/test/sql/alter/struct/drop_col_struct.test

@@ -0,0 +1,52 @@
+# name: test/sql/alter/struct/drop_col_struct.test
+# description: Test ALTER TABLE DROP COLUMN: drop column from a struct
+# group: [struct]
+
+statement ok
+CREATE TABLE test(s STRUCT(i INTEGER, j INTEGER))
+
+statement ok
+INSERT INTO test VALUES (ROW(1, 1)), (ROW(2, 2))
+
+# drop a column from a struct
+statement ok
+ALTER TABLE test DROP COLUMN s.i
+
+query I
+SELECT * FROM test
+----
+{'j': 1}
+{'j': 2}
+
+# we cannot drop the last column
+statement error
+ALTER TABLE test DROP COLUMN s.j
+----
+last field
+
+# does not exists
+statement error
+ALTER TABLE test DROP COLUMN s.v
+----
+does not exist
+
+statement ok
+ALTER TABLE test DROP COLUMN IF EXISTS s.v
+
+# not a struct
+statement error
+ALTER TABLE test DROP COLUMN s.j.a
+----
+Catalog Error: Cannot drop field from column "s" - not a nested type
+
+# field does not exist
+statement error
+ALTER TABLE test DROP COLUMN z.j
+----
+does not exist
+
+# nested column does not exist
+statement error
+ALTER TABLE test DROP COLUMN s.v1.a
+----
+does not exist

external/duckdb/test/sql/alter/struct/rename_col_nested_struct.test

@@ -0,0 +1,36 @@
+# name: test/sql/alter/struct/rename_col_nested_struct.test
+# description: Test ALTER TABLE RENAME COLUMN: rename column of a nested struct
+# group: [struct]
+
+statement ok
+CREATE TABLE test(s STRUCT(s2 STRUCT(v1 INT, v2 INT)))
+
+statement ok
+INSERT INTO test VALUES (ROW(ROW(1, 1))), (ROW(ROW(2, 2)))
+
+# rename a column of a nested struct
+statement ok
+ALTER TABLE test RENAME s.s2.v1 TO i
+
+query I
+SELECT * FROM test
+----
+{'s2': {'i': 1, 'v2': 1}}
+{'s2': {'i': 2, 'v2': 2}}
+
+
+# already exists
+statement error
+ALTER TABLE test RENAME COLUMN s.s2.v2 TO i
+----
+already exists
+
+# rename the entire struct
+statement ok
+ALTER TABLE test RENAME COLUMN s.s2 TO x
+
+query I
+SELECT * FROM test
+----
+{'x': {'i': 1, 'v2': 1}}
+{'x': {'i': 2, 'v2': 2}}

external/duckdb/test/sql/alter/struct/rename_col_struct.test

@@ -0,0 +1,60 @@
+# name: test/sql/alter/struct/rename_col_struct.test
+# description: Test ALTER TABLE RENAME COLUMN: rename column of a struct
+# group: [struct]
+
+statement ok
+CREATE TABLE test(s STRUCT(i INTEGER, j INTEGER))
+
+statement ok
+INSERT INTO test VALUES (ROW(1, 1)), (ROW(2, 2))
+
+# add a column to a struct
+statement ok
+ALTER TABLE test RENAME s.i TO v1
+
+query I
+SELECT * FROM test
+----
+{'v1': 1, 'j': 1}
+{'v1': 2, 'j': 2}
+
+statement ok
+BEGIN
+
+statement ok
+ALTER TABLE test RENAME s.j TO v2
+
+query I
+SELECT * FROM test
+----
+{'v1': 1, 'v2': 1}
+{'v1': 2, 'v2': 2}
+
+statement ok
+ROLLBACK
+
+query I
+SELECT * FROM test
+----
+{'v1': 1, 'j': 1}
+{'v1': 2, 'j': 2}
+
+statement error
+ALTER TABLE test RENAME s.j TO v1
+----
+already exists
+
+statement error
+ALTER TABLE test RENAME s.j.x TO v2
+----
+Catalog Error: Cannot rename field from column "s" - not a nested type
+
+statement error
+ALTER TABLE test RENAME s.i TO v2
+----
+does not exist
+
+statement error
+ALTER TABLE test RENAME x.i TO v2
+----
+does not exist