Character Data Types

The character data types enable the database server to store text strings.

(1)
Character Data Type

1 
2.1 CHAR
2.1 CHARACTER
2.1 1 NCHAR
2.1!  (  1  )
2.1  ( size )
1 
2.1 1 NVARCHAR
2.1 VARCHAR
2.1 CHARACTER VARYING
1 (max
2.1!  , 0
2.1?  , reserve
1 )
1  LVARCHAR
2.1!  ( 2048 )
2.1  ( max )
Notes:
  • 1 Localized Collation
Element Description Restrictions Syntax
max Maximum size in bytes. For VARCHAR and NVARCHAR, this is required. LVARCHAR default is 2048 VARCHAR and NVARCHAR: Integer; 1 < max < 255 (or 1 < max < 254, if indexed) LVARCHAR: 1 < max < 32,739 Literal Number
reserve Bytes reserved. Default is 0. Integer; 0 < reserve < max Literal Number
size Size in bytes. Default is 1. Integer; 1 < size < 32,767 Literal Number

The database server issues an error if the data type declaration includes empty parentheses, such as LVARCHAR( ). To declare a CHAR or LVARCHAR data type of the default length, simply omit any (size) or (max) specification. The CREATE TABLE statement of HCL OneDB™ accepts VARCHAR and NVARCHAR column declarations that have no (max) nor (max, reserve) specifications, using ( 1, 0 ) as the (max, reserve) default values for the column.

The following table summarizes the built-in character data types.
Data Type Description
CHAR Stores single-byte or multibyte text strings of fixed length (up to 32,767 bytes); supports code-set order in collation of text data. Default size is 1 byte.
CHARACTER Synonym for CHAR
CHARACTER VARYING ANSI-compliant synonym for VARCHAR
LVARCHAR Stores single-byte or multibyte text strings of varying length (up to 32,739 bytes). The size of other columns in the same table can further reduce this upper limit. Default size is 2,048 bytes.
NCHAR Stores single-byte or multibyte text strings of fixed length (up to 32,767 bytes); supports localized collation of text data.
NVARCHAR Stores single-byte or multibyte text strings of varying length (up to 255 bytes); supports localized collation of text data.
VARCHAR Stores single-byte or multibyte text strings of varying length (up to 255 bytes); supports code-set order collation of text data.