HSQLDB – Data Types

This chapter explains the different data types of HSQLDB. HSQLDB server offers six categories of data types.

Exact Numeric Data Types

Data TypeFromTo
bigint-9,223,372,036,854,775,8089,223,372,036,854,775,807
int-2,147,483,6482,147,483,647
smallint-32,76832,767
tinyint0255
bit01
decimal-10^38 +110^38 -1
numeric-10^38 +110^38 -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 TypeFromTo
float-1.79E + 3081.79E + 308
real-3.40E + 383.40E + 38

Date and Time Data Types

Data TypeFromTo
datetimeJan 1, 1753Dec 31, 9999
smalldatetimeJan 1, 1900Jun 6, 2079
dateStores a date like June 30, 1991
timeStores a time of the 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 TypeDescription
charThe maximum length of 8,000 characters (Fixed length non-Unicode characters)
varcharMaximum of 8,000 characters (Variable-length non-Unicode data)
varchar(max)The maximum length of 231 characters, variable-length non-Unicode data (SQL Server 2005 only)
textVariable-length non-Unicode data with a maximum length of 2,147,483,647 characters

Unicode Character Strings Data Types

Data TypeDescription
ncharThe maximum length of 4,000 characters (Fixed length Unicode)
nvarcharMaximum length of 4,000 characters (Variable length Unicode)
nvarchar(max)The maximum length of 231 characters (SQL Server 2005 only),(Variable-length Unicode)
ntextMaximum length of 1,073,741,823 characters (Variable length Unicode)

Binary Data Types

Data TypeDescription
binaryThe maximum length of 8,000 bytes (Fixed-length binary data)
varbinaryThe maximum length of 8,000 bytes (Variable-length binary data)
varbinary(max)The maximum length of 231 bytes (SQL Server 2005 only), (Variable length Binary data)
imageThe maximum length of 2,147,483,647 bytes (Variable length Binary Data)

Misc Data Types

Data TypeDescription
sql_variantStores values of various SQL Server-supported data types, except text, text, and timestamp
timestampStores a database-wide unique number that gets updated every time a row gets updated
uniqueidentifierStores a globally unique identifier (GUID)
xmlStores XML data. You can store XML instances in a column or a variable (SQL Server 2005 only)
cursorReference to a cursor object
tableStores a result set for later processing

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