mysql Tinyint como no firmado

Question

Intenté escribir t = t | 128 pero obtuve un error de fuera de rango. Sospecho que tinyint está firmado. Sin embargo, http://dev.mysql.com/doc/refman/5.5/en/numeric-types.html dice que puede estar sin firmar (abajo). Pero no dice cómo hacerlo sin firmar. ¿Cómo puedo?

Type  Storage Minimum Value  Maximum Value 
     (Bytes) (Signed/Unsigned) (Signed/Unsigned) 
TINYINT  1   -128     127 
          0      255 
SMALLINT 2   -32768     32767 
          0      65535 
MEDIUMINT 3   -8388608    8388607 
          0     16777215 
INT   4   -2147483648   2147483647 
          0     4294967295 
BIGINT  8  -9223372036854775808 9223372036854775807 
          0    18446744073709551615 

Answer 1

UNSIGNED es un atributo que se puede agregar a muchos tipos. Desde el documentation:

data_type:

BIT[(length)] 
    | TINYINT[(length)] [UNSIGNED] [ZEROFILL] 
    | SMALLINT[(length)] [UNSIGNED] [ZEROFILL] 
    | MEDIUMINT[(length)] [UNSIGNED] [ZEROFILL] 
    | INT[(length)] [UNSIGNED] [ZEROFILL] 
    | INTEGER[(length)] [UNSIGNED] [ZEROFILL] 
    | BIGINT[(length)] [UNSIGNED] [ZEROFILL] 
    | REAL[(length,decimals)] [UNSIGNED] [ZEROFILL] 
    | DOUBLE[(length,decimals)] [UNSIGNED] [ZEROFILL] 
    | FLOAT[(length,decimals)] [UNSIGNED] [ZEROFILL] 
    | DECIMAL[(length[,decimals])] [UNSIGNED] [ZEROFILL] 
    | NUMERIC[(length[,decimals])] [UNSIGNED] [ZEROFILL] 
    | DATE 
    | TIME 
    | TIMESTAMP 
    | DATETIME 
    | YEAR 
    | CHAR[(length)] 
     [CHARACTER SET charset_name] [COLLATE collation_name] 
    | VARCHAR(length) 
     [CHARACTER SET charset_name] [COLLATE collation_name] 
    | BINARY[(length)] 
    | VARBINARY(length) 
    | TINYBLOB 
    | BLOB 
    | MEDIUMBLOB 
    | LONGBLOB 
    | TINYTEXT [BINARY] 
     [CHARACTER SET charset_name] [COLLATE collation_name] 
    | TEXT [BINARY] 
     [CHARACTER SET charset_name] [COLLATE collation_name] 
    | MEDIUMTEXT [BINARY] 
     [CHARACTER SET charset_name] [COLLATE collation_name] 
    | LONGTEXT [BINARY] 
     [CHARACTER SET charset_name] [COLLATE collation_name] 
    | ENUM(value1,value2,value3,...) 
     [CHARACTER SET charset_name] [COLLATE collation_name] 
    | SET(value1,value2,value3,...) 
     [CHARACTER SET charset_name] [COLLATE collation_name] 
    | spatial_type 

Answer 2

Se marca el signo con la palabra clave unsigned. Por lo tanto, al hacer una mesa para un ejemplo:

CREATE TABLE `example_table` (
    `example_col` tinyint(3) unsigned NOT NULL 
); 

Ver Create Table vez más, o la Alter table.

Answer 3

En primer lugar, debe hacer algo con valores negativos, de lo contrario ALTER TABLE...UNSIGNED arrojará un error. Por ejemplo, puede aumentar todos los valores:

UPDATE table SET tiny_field = tiny_field + 128; 

Luego use ALTER TABLE para cambiar el tipo de campo/opción.