CREATE TABLE t (c1 INT PRIMARY KEY, c2 INT NOT NULL, c3 INT) ENGINE=InnoDB;
INSERT INTO t VALUES (1,2,3),(4,5,6),(7,8,9);
ALTER TABLE t CHANGE c1 c1 INT NULL FIRST, ALGORITHM=INPLACE;
affected rows: 0
info: Records: 0  Duplicates: 0  Warnings: 0
set @old_sql_mode = @@sql_mode;
set @@sql_mode = 'STRICT_TRANS_TABLES';
ALTER TABLE t MODIFY c3 INT NOT NULL, ALGORITHM=INPLACE;
affected rows: 0
info: Records: 0  Duplicates: 0  Warnings: 0
set @@sql_mode = @old_sql_mode;
ALTER TABLE t CHANGE c2 c2 INT, CHANGE c2 c2 INT NOT NULL;
ERROR 42S22: Unknown column 'c2' in 't'
ALTER TABLE t MODIFY c2 INT, MODIFY c2 INT NOT NULL;
ERROR 42S22: Unknown column 'c2' in 't'
ALTER TABLE t MODIFY c2 INT UNSIGNED, MODIFY c2 INT;
ERROR 42S22: Unknown column 'c2' in 't'
ALTER TABLE t MODIFY c2 CHAR(1) NOT NULL, MODIFY c2 INT NOT NULL;
ERROR 42S22: Unknown column 'c2' in 't'
ALTER TABLE t CHANGE c2 c2 INT NOT NULL;
affected rows: 0
info: Records: 0  Duplicates: 0  Warnings: 0
ALTER TABLE t MODIFY c2 INT NOT NULL;
affected rows: 0
info: Records: 0  Duplicates: 0  Warnings: 0
connect  con1,localhost,root,,;
connection con1;
SET SQL_MODE='STRICT_ALL_TABLES';
UPDATE t SET c2=NULL;
ERROR 23000: Column 'c2' cannot be null
SELECT * FROM t;
c1	c2	c3
1	2	3
4	5	6
7	8	9
connection default;
ALTER TABLE t MODIFY c2 INT, ALGORITHM=INPLACE;
connection con1;
BEGIN;
UPDATE t SET c2=NULL;
SELECT * FROM t;
c1	c2	c3
1	NULL	3
4	NULL	6
7	NULL	9
ROLLBACK;
SELECT * FROM t;
c1	c2	c3
1	2	3
4	5	6
7	8	9
disconnect con1;
connection default;
ALTER TABLE t MODIFY c2 INT NULL, ALGORITHM=INPLACE;
SELECT * FROM INFORMATION_SCHEMA.INNODB_SYS_TABLES
WHERE NAME='test/t';
TABLE_ID	NAME	FLAG	N_COLS	SPACE	ROW_FORMAT	ZIP_PAGE_SIZE	SPACE_TYPE
#	test/t	33	6	#	Dynamic	0	Single
DROP TABLE t;