this chapter explains the different datatypes of hsqldb. hsqldb server offers six categories of data types.
exact numeric data types
| data type |
from |
to |
| bigint |
-9,223,372,036,854,775,808 |
9,223,372,036,854,775,807 |
| int |
-2,147,483,648 |
2,147,483,647 |
| smallint |
-32,768 |
32,767 |
| tinyint |
0 |
255 |
| bit |
0 |
1 |
| decimal |
-10^38 +1 |
10^38 -1 |
| numeric |
-10^38 +1 |
10^38 -1 |
| money |
-922,337,203,685,477.5808 |
+922,337,203,685,477.5807 |
| smallmoney |
-214,748.3648 |
+214,748.3647 |
approximate numeric data types
| data type |
from |
to |
| float |
-1.79e + 308 |
1.79e + 308 |
| real |
-3.40e + 38 |
3.40e + 38 |
date and time data types
| data type |
from |
to |
| datetime |
jan 1, 1753 |
dec 31, 9999 |
| smalldatetime |
jan 1, 1900 |
jun 6, 2079 |
| date |
stores a date like june 30, 1991 |
| time |
stores a time of day like 12:30 p.m. |
note − here, datetime has 3.33 milliseconds accuracy whereas small datetime has 1- minute accuracy.
character strings data types
| data type |
description |
| char |
maximum length of 8,000 characters (fixed length non-unicode characters) |
| varchar |
maximum of 8,000 characters (variable-length non-unicode data) |
| varchar(max) |
maximum length of 231 characters, variable-length non-unicode data (sql server 2005 only) |
| text |
variable-length non-unicode data with a maximum length of 2,147,483,647 characters |
unicode character strings data types
| data type |
description |
| nchar |
maximum length of 4,000 characters (fixed length unicode) |
| nvarchar |
maximum length of 4,000 characters (variable length unicode) |
| nvarchar(max) |
maximum length of 231 characters (sql server 2005 only),(variable length unicode) |
| ntext |
maximum length of 1,073,741,823 characters (variable length unicode) |
binary data types
| data type |
description |
| binary |
maximum length of 8,000 bytes (fixed length binary data) |
| varbinary |
maximum length of 8,000 bytes (variable length binary data) |
| varbinary(max) |
maximum length of 231 bytes (sql server 2005 only), (variable length binary data) |
| image |
maximum length of 2,147,483,647 bytes (variable length binary data) |
misc data types
| data type |
description |
| sql_variant |
stores values of various sql server-supported data types, except text, ntext, and timestamp |
| timestamp |
stores a database-wide unique number that gets updated every time a row gets updated |
| uniqueidentifier |
stores a globally unique identifier (guid) |
| xml |
stores xml data. you can store xml instances in a column or a variable (sql server 2005 only) |
| cursor |
reference to a cursor object |
| table |
stores a result set for later processing |
