Difference between TinyInt / SmallInt / MediumInt / Int / BigInt in MySQL data type ?
I want to use an [unsigned] integer field with 11 length, what should i use ?
[I'm using PHPMyAdmin]
Type Range
TINYINT -128 to 127<br>
SMALLINT -32768 to 32767<br>
MEDIUMINT -8388608 to 8388607<br>
INT -2147483648 to 2147483647<br>
BIGINT -9223372036854775808 to 9223372036854775807
You should use BIGINT.
Check the official documentation:
http://dev.mysql.com/doc/refman/5.0/en/numeric-types.html
Related
I was wondering if I can set a max value in column definition of MySQL, just like we set a default value during column definition. If it can be done, how can it be achieved ? Example format:
int(5) not null default 1 <Something to set max value> ??
In table definition, you can only specify maximum number of characters, for example, when you specify a column as int(5), you are limiting the field to 5 bits.
Please refer to the documentation.
To make sure the column will not accept an integer greather that 50 for exeample, you will need to use triggers for example:
CREATE TRIGGER check_trigger
BEFORE INSERT
ON table
FOR EACH ROW
BEGIN
IF NEW.age<0 OR NEW.age>50 THEN
CALL `Error: Wrong values for age`; -- this trick will throw an error
END IF;
END
You can only control the max values of a column by changing the type.
If your minimum value desired is -128 and your max required is 127, then you can go with a TINYINT(). If you need between -32768 and 32767, then you need a SMALLINT(), and so on.
Source: MySQL Docs: Integer Types (Exact Value) - INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT
Presuming you are dealing with "max" and "min" integers, for instance...
TINYINT : 1 byte, -128 to 127 signed, 0 to 255 unsigned
SMALLINT : 2 bytes, -32768 to 32767 signed, 0 to 65535 unsigned
MEDIUMINT : 3 bytes, -8388608 to 8388607 signed, 0 to 16777215 unsigned
INT : 4 bytes, -2147483648 to 2147483647 signed, 0 to 4294967295 unsigned
BIGINT : 8 bytes, -2^63 to 2^63-1 signed, 0 to 2^64-1 unsigned
I have a mysql database in which i am using auto_increment(integer), can you tell me till what integer it can incremented. How we can increase the limit of auto_increment?
The limit of an auto_increment column is the size of the column:
Use a large enough integer data type for the AUTO_INCREMENT column to hold the maximum sequence value you will need. When the column reaches the upper limit of the data type, the next attempt to generate a sequence number fails. For example, if you use TINYINT, the maximum permissible sequence number is 127. For TINYINT UNSIGNED, the maximum is 255.
The limits of the integer types are:
TINYINT - 127
UNSIGNED TINYINT - 255
SMALLINT - 32767
UNSIGNED SMALLINT - 65535
MEDIUMINT - 8388607
UNSIGNED MEDIUMINT - 16777215
INT - 2147483647
UNSIGNED INT - 4294967295
BIGINT - 9223372036854775807
UNSIGNED BIGINT - 18446744073709551615
Integer can go as high as 2147483647. If unsigned it can be 4294967295.
See this chart for all of the integer values.
I'm under the assumption that INT(1) is the exact same thing as TINYINT(1) but I really have no idea. Whenever I've had values that can only be a single integer (e.g. a value 0-9), I've always just used INT(1) to say it's an integer and it will only be one character, which I assume means that it could only be a value 0 through 9 (please explain this to me if I'm wrong). I've always just ignored the other types of INT that you can cast the number as. I'm no MySQL savvy and tend to avoid the more complicated things you can do with it.
So my question, is there any difference between the various integer types INT, TINYINT, SMALLINT, MEDIUMINT, and BIGINT if you define a length of 1 for each type;? If not, should I use them anyways (I can see using them for more semantic meaning, TINYINT being more specific than just INT)? If so, could I easily (and/or should I) just go through my database and change all my INT(1) fields to TINYINT(1) fields?
Here you'll understand it in a better way!
tinyint: 1 byte, -128 to +127 / 0 to 255 (unsigned)
smallint: 2 bytes, -32,768 to +32,767 / 0 to 65,535 (unsigned)
mediumint: 3 bytes, -8,388,608 to 8,388,607 / 0 to 16,777,215 (unsigned)
int/integer: 4 bytes, -2,147,483,648 to +2,147,483,647 / 0 to 4,294,967,295 (unsigned)
bigint: 8 bytes, -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 / 0 to 18,446,744,073,709,551,615 (unsigned)
The number in parentheses for integer column types is the "display width". This does not effect the storage requirements as they are pre-defined.
Further reading
http://dev.mysql.com/doc/refman/5.0/en/data-types.html
http://dev.mysql.com/doc/refman/5.0/en/numeric-types.html
To summarize the accepted answered :
The number in parentheses indicates the *number of characters to display that field*, **not** the storage size of the field.
But if you want to know the storage size, you should check the MySQL source documents.
Source: MySQL Docs: Integer Types (Exact Value) - INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT
Direct quote from source documentation :
TINYINT : 1 byte, -128 to 127 signed, 0 to 255 unsigned
SMALLINT : 2 bytes, -32768 to 32767 signed, 0 to 65535 unsigned
MEDIUMINT : 3 bytes, -8388608 to 8388607 signed, 0 to 16777215 unsigned
INT : 4 bytes, -2147483648 to 2147483647 signed, 0 to 4294967295 unsigned
BIGINT : 8 bytes, -2^63 to 2^63-1 signed, 0 to 2^64-1 unsigned
How do I represent this data in mysql?
16 bit unsigned integer -----Range: 0x0000 - 0xFFF7
64 bit unsigned int. Depicted as xx:xx:xx:xx:xx:xx:xx:xx -----Range: 0x0000 - 0xFFFFFFFFFFFFFFFF
2 bits ----- 00 - None, 01 - Residential Security, 10 - High Security
32 bit unsigned int
Should I convert everything to string and convert it at application layer?
According to MySQL's Overview of Numeric Types:
UNSIGNED SMALLINT: range is 0 to 65535. This would be sufficient for 16-bit unsigned ints.
UNSIGNED TINYINT: range is 0 to 255. Sufficient for 2-bit unsigned int. It appears you would need to preserve leading zeroes, so use ZEROFILL too. To keep the value to just two characters wide, you can specify UNSIGNED ZEROFILL TINYINT(2).
UNSIGNED INT: range is 0 to 4294967295. Sufficient for 32-bit unsigned int.
UNSIGNED BIGINT: range is 0 to 18446744073709551615. See below:
The last one, the 64-bit unsigned int, has a couple of caveats, from the above linked page:
All arithmetic is done using signed BIGINT or DOUBLE values, so you should not use unsigned big integers larger than 9223372036854775807 (63 bits) except with bit functions! If you do that, some of the last digits in the result may be wrong because of rounding errors when converting a BIGINT value to a DOUBLE.
You can always store an exact integer value in a BIGINT column by storing it using a string. In this case, MySQL performs a string-to-number conversion that involves no intermediate double-precision representation.
The -, +, and * operators use BIGINT arithmetic when both operands are integer values. This means that if you multiply two big integers (or results from functions that return integers), you may get unexpected results when the result is larger than 9223372036854775807.
MySQL support several data types. See MySQL Data Types
UNSIGNED BIGINT : 8-byte (64-bit) integer
UNSIGNED INT : 4-byte (32-bit) integer
UNSIGNED SMALLINT : 2-byte (16-bit) integer
For the 2-bit type, you may use the TINYINT (8-bit) or the ENUM datatype.
What's the difference in int(11) and int(11) UNSIGNED ?
An UNSIGNED type cannot be negative, but on the other hand it has twice as large a range for the positive integers. The types TINYINT, SMALLINT, MEDIUMINT,
INT and BIGINT all have signed and unsigned versions.
For INT the ranges are defined as follows:
Type Storage Min Max
INT 4 -2147483648 2147483647
INT UNSIGNED 4 0 4294967295
The signed and unsigned types take the same storage space (4 bytes for INT).
See the documentation for more details.
INT goes from -2147483648 to +2147483647
UNSIGNED INT goes from 0 to 4294967295
the 11 between the braces has no effect on the number, just how it's displayed.
UNSIGNED means that it can hold only nonnegative values, i.e. it can't hold for example -20
UNSIGNED is exactly that, its all positive (no sign) numbers. The size of bytes is the same, but if your data is never negative you can get larger positive numbers out of it. The 11 is the default of how many characters it will fetch and display. For the exact size, do a search for the DBMS you are using and the type.
All integer types can have an optional (nonstandard) attribute UNSIGNED. Unsigned type can be used to permit only nonnegative numbers in a column or when you need a larger upper numeric range for the column. For example, if an INT column is UNSIGNED, the size of the column's range is the same but its endpoints shift from -2147483648 and 2147483647 up to 0 and 4294967295.
see here: http://dev.mysql.com/doc/refman/5.0/en/numeric-types.html
The unsigned one can't hold negative numbers.
An unsigned integer can handle values from 0 to 2^(size in bits of the integer field). A signed integer can handle values from -2^(size of the integer field-1) to 2^(size of the integer field-1)-1.
I think you may want to know the difference between int and int(10).
Let's give an example for int(10) one with zerofill keyword, one not, the table likes that:
create table tb_test_int_type(
int_10 int(10),
int_10_with_zf int(10) zerofill,
unit int unsigned
);
Let's insert some data:
insert into tb_test_int_type(int_10, int_10_with_zf, unit)
values (123456, 123456,3147483647), (123456, 4294967291,3147483647)
;
Then
select * from tb_test_int_type;
# int_10, int_10_with_zf, unit
'123456', '0000123456', '3147483647'
'123456', '4294967291', '3147483647'
We can see that
with keyword zerofill, num less than 10 will fill 0, but without zerofill it won't
Secondly with keyword zerofill, int_10_with_zf becomes unsigned int type, if you insert a minus you will get error Out of range value for column...... But you can insert minus to int_10. Also if you insert 4294967291 to int_10 you will get error Out of range value for column.....
Conclusion:
int(X) without keyword zerofill, is equal to int range -2147483648~2147483647
int(X) with keyword zerofill, the field is equal to unsigned int range 0~4294967295, if num's length is less than X it will fill 0 to the left