| Type |
Description |
| String data types |
| CHAR(size) |
A FIXED length string (can contain letters, numbers, and special characters). The size parameter specifies the column length in characters - can be from 0 to 255. Default is 1 |
| VARCHAR(size) |
A VARIABLE length string (can contain letters, numbers, and special characters). The size parameter specifies the maximum column length in characters - can be from 0 to 65535 |
| BINARY(size) |
Equal to CHAR(), but stores binary byte strings. The size parameter specifies the column length in bytes. Default is 1 |
| VARBINARY(size) |
Equal to VARCHAR(), but stores binary byte strings. The size parameter specifies the maximum column length in bytes. |
| TINYBLOB |
For BLOBs (Binary Large OBjects). Max length: 255 bytes |
| TINYTEXT |
Holds a string with a maximum length of 255 characters |
| TEXT(size) |
Holds a string with a maximum length of 65,535 bytes |
| BLOB(size) |
For BLOBs (Binary Large OBjects). Holds up to 65,535 bytes of data |
| MEDIUMTEXT |
Holds a string with a maximum length of 16,777,215 characters |
| MEDIUMBLOB |
For BLOBs (Binary Large OBjects). Holds up to 16,777,215 bytes of data |
| LONGTEXT |
Holds a string with a maximum length of 4,294,967,295 characters |
| ENUM(val1, val2, val3, ...) |
A string object that can have only one value, chosen from a list of possible values. You can list up to 65535 values in an ENUM list. If a value is inserted that is not in the list, a blank value will be inserted. The values are sorted in the order you enter them |
| SET(val1, val2, val3, ...) |
A string object that can have 0 or more values, chosen from a list of possible values. You can list up to 64 values in a SET list |
| Numeric data types |
| BIT(size) |
A bit-value type. The number of bits per value is specified in size. The size parameter can hold a value from 1 to 64. The default value for size is 1. |
| TINYINT(size) |
A very small integer. Signed range is from -128 to 127. Unsigned range is from 0 to 255. The size parameter specifies the maximum display width (which is 255) |
| BOOL |
Zero is considered as false, nonzero values are considered as true. |
| BOOLEAN |
Equal to BOOL |
| SMALLINT(size) |
A small integer. Signed range is from -32768 to 32767. Unsigned range is from 0 to 65535. The size parameter specifies the maximum display width (which is 255) |
| MEDIUMINT(size) |
A medium integer. Signed range is from -8388608 to 8388607. Unsigned range is from 0 to 16777215. The size parameter specifies the maximum display width (which is 255) |
| INT(size) |
A medium integer. Signed range is from -2147483648 to 2147483647. Unsigned range is from 0 to 4294967295. The size parameter specifies the maximum display width (which is 255) |
| INTEGER(size) |
Equal to INT(size) |
| BIGINT(size) |
A large integer. Signed range is from -9223372036854775808 to 9223372036854775807. Unsigned range is from 0 to 18446744073709551615. The size parameter specifies the maximum display width (which is 255) |
| FLOAT(size, d) |
A floating point number. The total number of digits is specified in size. The number of digits after the decimal point is specified in the d parameter. This syntax is deprecated in MySQL 8.0.17, and it will be removed in future MySQL versions |
| FLOAT(p) |
A floating point number. MySQL uses the p value to determine whether to use FLOAT or DOUBLE for the resulting data type. If p is from 0 to 24, the data type becomes FLOAT(). If p is from 25 to 53, the data type becomes DOUBLE() |
| DOUBLE(size, d) |
A normal-size floating point number. The total number of digits is specified in size. The number of digits after the decimal point is specified in the d parameter |
| DOUBLE PRECISION(size, d) |
A normal-size floating point number. The total number of digits is specified in size. The number of digits after the decimal point is specified in the d parameter |
| DECIMAL(size, d) |
An exact fixed-point number. The total number of digits is specified in size. The number of digits after the decimal point is specified in the d parameter. The maximum number for size is 65. The maximum number for d is 30. The default value for size is 10. The default value for d is 0. |
| DEC(size, d) |
Equal to DECIMAL(size,d) |
| Date and Time data types |
| DATE |
A date. Format: YYYY-MM-DD. The supported range is from '1000-01-01' to '9999-12-31' |
| DATETIME(fsp) |
A date and time combination. Format: YYYY-MM-DD hh:mm:ss. The supported range is from '1000-01-01 00:00:00' to '9999-12-31 23:59:59'. Adding DEFAULT and ON UPDATE in the column definition to get automatic initialization and updating to the current date and time |
| TIMESTAMP(fsp) |
A timestamp. TIMESTAMP values are stored as the number of seconds since the Unix epoch ('1970-01-01 00:00:00' UTC). Format: YYYY-MM-DD hh:mm:ss. The supported range is from '1970-01-01 00:00:01' UTC to '2038-01-09 03:14:07' UTC. Automatic initialization and updating to the current date and time can be specified using DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP in the column definition |
| TIME(fsp) |
A time. Format: hh:mm:ss. The supported range is from '-838:59:59' to '838:59:59' |
| YEAR |
A year in four-digit format. Values allowed in four-digit format: 1901 to 2155, and 0000.
MySQL 8.0 does not support year in two-digit format. |
| Type |
Description |
Max size |
Storage |
| String data types |
| CHAR(size) |
Fixed width character string |
8,000 characters |
Defined width |
| varchar(n) |
Variable width character string |
8,000 characters |
2 bytes + number of chars |
| varchar(max) |
Variable width character string |
1,073,741,824 characters |
2 bytes + number of chars |
| text |
Variable width character string |
2GB of text data |
4 bytes + number of chars |
| nchar |
Fixed width Unicode string |
4,000 characters |
Defined width x 2 |
| nvarchar |
Variable width Unicode string |
4,000 characters |
|
| nvarchar(max) |
Variable width Unicode string |
536,870,912 characters |
|
| ntext |
Variable width Unicode string |
2GB of text data |
|
| binary(n) |
Fixed width binary string |
8,000 bytes |
|
| varbinary |
Variable width binary string |
8,000 bytes |
|
| varbinary(max) |
Variable width binary string |
2GB |
|
| image |
Variable width binary string |
2GB |
|
| Numeric data types |
| bit |
Integer that can be 0, 1, or NULL |
|
| tinyint |
Allows whole numbers from 0 to 255 |
1 byte |
| smallint |
Allows whole numbers between -32,768 and 32,767 |
2 bytes |
| int |
Allows whole numbers between -2,147,483,648 and 2,147,483,647 |
4 bytes |
| bigint |
Allows whole numbers between -9,223,372,036,854,775,808 and 9,223,372,036,854,775,807 |
8 bytes |
| decimal(p,s) |
Fixed precision and scale numbers.
Allows numbers from -10^38 +1 to 10^38 –1.
The p parameter indicates the maximum total number of digits that can be stored (both to the left and to the right of the decimal point). p must be a value from 1 to 38. Default is 18.
The s parameter indicates the maximum number of digits stored to the right of the decimal point. s must be a value from 0 to p. Default value is 0 |
5-17 bytes |
| numeric(p,s) |
Fixed precision and scale numbers.
Allows numbers from -10^38 +1 to 10^38 –1.
The p parameter indicates the maximum total number of digits that can be stored (both to the left and to the right of the decimal point). p must be a value from 1 to 38. Default is 18.
The s parameter indicates the maximum number of digits stored to the right of the decimal point. s must be a value from 0 to p. Default value is 0 |
5-17 bytes |
| smallmoney |
Monetary data from -214,748.3648 to 214,748.3647 |
4 bytes |
| float(n) |
Floating precision number data from -1.79E + 308 to 1.79E + 308.
The n parameter indicates whether the field should hold 4 or 8 bytes. float(24) holds a 4-byte field and float(53) holds an 8-byte field. Default value of n is 53. |
4 or 8 bytes |
| real |
Floating precision number data from -3.40E + 38 to 3.40E + 38 |
4 bytes |
| Date and Time data types |
| datetime |
From January 1, 1753 to December 31, 9999 with an accuracy of 3.33 milliseconds |
8 bytes |
| datetime2 |
From January 1, 0001 to December 31, 9999 with an accuracy of 100 nanoseconds |
6-8 bytes |
| smalldatetime |
From January 1, 1900 to June 6, 2079 with an accuracy of 1 minute |
4 bytes |
| date |
Store a date only. From January 1, 0001 to December 31, 9999 |
3 bytes |
| time |
Store a time only to an accuracy of 100 nanoseconds |
3-5 bytes |
| datetimeoffset |
The same as datetime2 with the addition of a time zone offset |
8-10 bytes |
| timestamp |
Stores a unique number that gets updated every time a row gets created or modified. The timestamp value is based upon an internal clock and does not correspond to real time. Each table may have only one timestamp variable |
|
| Other data types |
| sql_variant |
Stores up to 8,000 bytes of data of various data types, except text, ntext, and timestamp |
| uniqueidentifier |
Stores a globally unique identifier (GUID) |
| xml |
Stores XML formatted data. Maximum 2GB |
| cursor |
Stores a reference to a cursor used for database operations |
| table |
Stores a result-set for later processing |
| Type |
Max size |
Description |
| Character Datatypes |
| char(size) |
Maximum size of 2000 bytes. |
Where size is the number of characters to store. Fixed-length strings. Space padded. |
| nchar(size) |
Maximum size of 2000 bytes. |
Where size is the number of characters to store. Fixed-length NLS string Space padded. |
| nvarchar2(size) |
Maximum size of 4000 bytes. |
Where size is the number of characters to store. Variable-length NLS string. |
| varchar2(size) |
Maximum size of 4000 bytes.
Maximum size of 32KB in PLSQL. |
Where size is the number of characters to store. Variable-length string. |
| long |
Maximum size of 2GB. |
Variable-length strings. (backward compatible) |
| raw |
Maximum size of 2000 bytes. |
Variable-length binary strings |
| long raw |
Maximum size of 2GB. |
Variable-length binary strings. (backward compatible) |
| Numeric Datatypes |
| number(p,s) |
Precision can range from 1 to 38.
Scale can range from -84 to 127.
|
Where p is the precision and s is the scale.
For example, number(7,2) is a number that has 5 digits before the decimal and 2 digits after the decimal.
|
| numeric(p,s) |
Precision can range from 1 to 38.
|
Where p is the precision and s is the scale.
For example, numeric(7,2) is a number that has 5 digits before the decimal and 2 digits after the decimal.
|
| dec(p,s) |
Precision can range from 1 to 38.
|
Where p is the precision and s is the scale.
For example, dec(3,1) is a number that has 2 digits before the decimal and 1 digit after the decimal. |
| decimal(p,s) |
Precision can range from 1 to 38.
|
Where p is the precision and s is the scale. For example, decimal(3,1) is a number that has 2 digits before the decimal and 1 digit after the decimal. |
| integer |
|
|
| int |
|
|
| smallint |
|
|
| real |
|
|
| double precision |
|
|
| Date/Time Datatypes |
| date |
A date between Jan 1, 4712 BC and Dec 31, 9999 AD.
|
|
| timestamp (fractional seconds precision) |
fractional seconds precision must be a number between 0 and 9. (default is 6)
|
Includes year, month, day, hour, minute, and seconds.
For example:
timestamp(6)
|
| timestamp (fractional seconds precision) with local time zone |
fractional seconds precision must be a number between 0 and 9. (default is 6)
|
Includes year, month, day, hour, minute, and seconds; with a time zone expressed as the session time zone.
For example:
timestamp(4) with local time zone
|
| interval year
(year precision)
to month |
year precision is the number of digits in the year. (default is 2)
|
Time period stored in years and months.
For example:
interval year(4) to month
|
| interval year(year precision)to month |
day precision must be a number between 0 and 9. (default is 2)fractional seconds precision must be a number between 0 and 9. (default is 6)
|
Time period stored in days, hours, minutes, and seconds.For example: interval day(2) to second(6)
|
| Large Object (LOB) Datatypes |
| bfile |
Maximum file size of 264-1 bytes.
|
File locators that point to a binary file on the server file system (outside the database).
|
| blob |
Store up to (4 gigabytes -1) * (the value of the CHUNK parameter of LOB storage).
|
Stores unstructured binary large objects.
|
| clob |
Store up to (4 gigabytes -1) * (the value of the CHUNK parameter of LOB storage) of character data.
|
Stores single-byte and multi-byte character data.
|
| nclob |
Store up to (4 gigabytes -1) * (the value of the CHUNK parameter of LOB storage) of character text data.
|
Stores Unicode data.
|
| Rowid Datatypes |
| rowid |
The format of the rowid is: BBBBBBB.RRRR.FFFFF
Where BBBBBBB is the block in the database file;
RRRR is the row in the block;
FFFFF is the database file.
|
Fixed-length binary data. Every record in the database has a physical address or rowid.
|
| Type |
Max size |
Description |
| Double |
|
The double data type is used to store floating point values |
| String |
|
This is the most commonly used MongoDB data types, BSON strings are UTF-8. Drivers for each programming language convert from the string format of the language to UTF-8 while serializing and de-serializing BSON. This makes possible to easily store most international characters in BSON strings. The string must be valid to be saved |
| Object |
|
Object data type stores embedded documents. If a document contains another document in the form of the key-value pair then such type of document is known as an embedded document. |
| Array |
|
These MongoDB data types stores array. A set of values are represented as an array. This data type can store multiples of values and data types |
| Binary Data |
|
These MongoDB data types store the binary data in it. |
| Undefined |
|
This MongoDB data type stores the undefined values. |
| ObjectId |
|
This data type in MongoDB stores the unique key Id of documents stored. There is an_id field in MongoDB for each document. The data which is stored in Id is in hexadecimal format. The size of ObjectId is 12 bytes which are divided into four parts as follows. |
| Boolean |
|
Boolean data type stores Boolean values i.e. true/false. |
| Date |
|
Date data type stores current date or time. There are various methods to return date. It can be either as a string or as a date object. In the below table, we have discussed the methods for the date. |
| Null |
|
This MongoDB data types stores a null value in it |
| Regular Expression |
|
These MongoDB data types stores regular expressions in MongoDB. It maps directly to JavaScript RegExp. |
| JavaScript |
|
These MongoDB data types store the JavaScript data without a scope. There is another data type to store data with a scope |
| Symbol |
|
These MongoDB data types similar to the string data type. It is not supported by a shell. But if the shell gets a symbol from the database, it is converted into strings. |
| JavaScript with Scope |
|
These MongoDB data types store JavaScript data with a scope |
| Integer |
|
These MongoDB data types used to store an integer value. There are two forms available for this data type, 32 bits, and 64 bits. |
| Timestamp |
|
This data type is used to store a timestamp. Also, this is useful when we modify our data to keep a record. This is 64-bit value data type. |
| Min & Max key |
|
Min key compares the value of the lowest BSON element. Max key compares the value against the highest BSON element. Both are internal data types. |
Not all data types are supported by every relational database vendors. For example, Oracle database doesn’t support DATETIME and MySQL doesn’t support CLOB data type. So while designing database schema and writing sql queries, make sure to check if the data types are supported or not.
Data types listed here doesn’t include all the data types, these are the most popularly used data types. Some relational database vendors have their own data types that might be not listed here. For example, Microsoft SQL Server has money and smallmoney data types but since it’s not supported by other popular database vendors, it’s not listed here.
Every relational database vendor has it’s own maximum size limit for different data types, you don’t need to remember the limit. Idea is to have the knowledge of what data type to be used in a specific scenario.
