CHAR(size)

The CHAR data type is a fixed-length character string data type.

Syntax

CHAR[ACTER] [ (size) ]

size defines the maximum length of the character string, in byte or char units (depending on the character length semantics)
The maximum size of a CHAR type is 65534.
If no size is specified, it defaults to 1.

Usage

The CHAR type is typically used to store fixed-length character strings such as short codes (XB124), phone numbers (650-23-2345), vehicle identification numbers.

CHAR and CHARACTER are synonyms.

The size can be expressed in bytes or characters, depending on the length semantics used in programs. For more details about character length semantics, see Length semantics settings.

When size is not specified, the default length is 1.

CHAR variables are initialized to NULL in functions, modules and globals.

Text literals can be assigned to character string variables:

MAIN
  DEFINE c CHAR(10)
  LET c = "abcdef"
END MAIN

When assigning a non-NULL value, CHAR variables are always blank-padded:

MAIN
  DEFINE c CHAR(10)
  LET c = "abcdef"
  DISPLAY "[", c ,"]"   -- displays [abcdef    ]
END MAIN

Trailing blanks of a CHAR value are not significant in comparisons:

MAIN
  DEFINE c CHAR(5)
  LET c = "abc"
  IF c == "abc" THEN    -- evaluates to TRUE
     DISPLAY "equals"
  END IF
END MAIN

Numeric and date-time values can be directly assigned the character strings:

MAIN
  DEFINE c CHAR(50), da DATE, dec DECIMAL(10,2)
  LET da = TODAY
  LET dec = 345.12
  LET c = da, " : ", dec
END MAIN

When you insert character data from CHAR variables into CHAR columns in a database table, the column-value is blank-padded to the size of the column. Likewise, when you fetch CHAR column values into CHAR variables, the program variable is blank-padded to the size of the variable.

MAIN
  DEFINE c CHAR(10)
  DATABASE test1
  CREATE TABLE table1 ( k INT, x CHAR(10) )
  LET c = "abc"
  INSERT INTO table1 VALUES ( 1, c )
  SELECT x INTO c FROM table1 WHERE k = 1
  DISPLAY "[", vc ,"]"     -- displays [abc  ]
END MAIN

In SQL statements, the behavior of the comparison operators when using CHAR values may vary from one database to the other. However, most database engines ignore trailing blanks when compating CHAR values. For more details, see SQL portability.