HSQLDB – Data Types

HSQLDB – Data Types

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

Exact Numeric Data Types

Data TypeFromTo
decimal-10^38 +110^38 -1
numeric-10^38 +110^38 -1

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 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
charMaximum length of 8,000 characters (Fixed length non-Unicode characters)
varcharMaximum 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)
textVariable-length non-Unicode data with a maximum length of 2,147,483,647 characters

Unicode Character Strings Data Types

Data TypeDescription
ncharMaximum length of 4,000 characters (Fixed length Unicode)
nvarcharMaximum length of 4,000 characters (Variable length Unicode)
nvarchar(max)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
binaryMaximum length of 8,000 bytes (Fixed length binary data)
varbinaryMaximum length of 8,000 bytes (Variable length binary data)
varbinary(max)Maximum length of 231 bytes (SQL Server 2005 only), (Variable length Binary data)
imageMaximum 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, ntext, 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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