SIGNED | ZEROFILL] Description ----------- A very small integer. The signed range is -128 to 127. The unsigned range is 0 to 255. For details on the attributes, see Numeric Data Type Overview. INT1 is a synonym for TINYINT. BOOL and BOOLEAN are synonyms for TINYINT(1). Examples -------- CREATE TABLE tinyints (a TINYINT,b TINYINT UNSIGNED,c TINYINT ZEROFILL); With strict_mode set, the default from MariaDB 10.2.4: INSERT INTO tinyints VALUES (-10,-10,-10); ERROR 1264 (22003): Out of range value for column 'b' at row 1 INSERT INTO tinyints VALUES (-10,10,-10); ERROR 1264 (22003): Out of range value for column 'c' at row 1 INSERT INTO tinyints VALUES (-10,10,10); SELECT * FROM tinyints; +------+------+------+ | a | b | c | +------+------+------+ | -10 | 10 | 010 | +------+------+------+ INSERT INTO tinyints VALUES (128,128,128); ERROR 1264 (22003): Out of range value for column 'a' at row 1 INSERT INTO tinyints VALUES (127,128,128); SELECT * FROM tinyints; +------+------+------+ | a | b | c | +------+------+------+ | -10 | 10 | 010 | | 127 | 128 | 128 | +------+------+------+ With strict_mode unset, the default until MariaDB 10.2.3: INSERT INTO tinyints VALUES (-10,-10,-10); Query OK, 1 row affected, 2 warnings (0.08 sec) Warning (Code 1264): Out of range value for column 'b' at row 1 Warning (Code 1264): Out of range value for column 'c' at row 1 INSERT INTO tinyints VALUES (-10,10,-10); Query OK, 1 row affected, 1 warning (0.11 sec) Warning (Code 1264): Out of range value for column 'c' at row 1 INSERT INTO tinyints VALUES (-10,10,10); SELECT * FROM tinyints; +------+------+------+ | a | b | c | +------+------+------+ | -10 | 0 | 000 | | -10 | 10 | 000 | | -10 | 10 | 010 | +------+------+------+ INSERT INTO tinyints VALUES (128,128,128); Query OK, 1 row affected, 1 warning (0.19 sec) Warning (Code 1264): Out of range value for column 'a' at row 1 INSERT INTO tinyints VALUES (127,128,128); SELECT * FROM tinyints; +------+------+------+ | a | b | c | +------+------+------+ | -10 | 0 | 000 | | -10 | 10 | 000 | | -10 | 10 | 010 | | 127 | 128 | 128 | | 127 | 128 | 128 | +------+------+------+ URL: https://mariadb.com/kb/en/tinyint/https://mariadb.com/kb/en/tinyint/