DECIMAL or DEC

The DECIMAL function returns a decimal representation.

Numeric to Decimal

Read syntax diagramSkip visual syntax diagramDECIMALDEC( numeric-expression ,precision,scale )

String to Decimal

Read syntax diagramSkip visual syntax diagramDECIMALDEC( string-expression ,precision,scale,decimal-character )

Datetime to Decimal

Read syntax diagramSkip visual syntax diagramDECIMALDEC( datetime-expression ,precision,scale )

The DECIMAL function returns a decimal representation of:

  • A number
  • A character or graphic string representation of a decimal number
  • A character or graphic string representation of an integer
  • A character or graphic string representation of a floating-point number
  • A character or graphic string representation of a decimal floating-point number
  • A date
  • A time
  • A timestamp

Numeric to Decimal

numeric-expression
An expression that returns a value of any built-in numeric data type.
precision
An integer constant with a value greater than or equal to 1 and less than or equal to 63.

The default for precision depends on the data type of the numeric-expression:

  • 5 for small integer
  • 11 for large integer
  • 19 for big integer
  • 15 for floating point, decimal, numeric, or nonzero scale binary
  • 31 for decimal floating point
scale
An integer constant that is greater than or equal to 0 and less than or equal to precision. If not specified, the default is 0.

The result is the same number that would occur if the first argument were assigned to a decimal column or variable with a precision of precision and a scale of scale. An error is returned if the number of significant decimal digits required to represent the whole part of the number is greater than precision-scale. If the first argument can be null, the result can be null; if the first argument is null, the result is the null value.

String to Decimal

string-expression
An expression that returns a character-string or graphic-string representation of a number. Leading and trailing blanks are eliminated and the resulting string must conform to the rules for forming a floating-point, decimal floating-point, integer, or decimal constant.
precision
An integer constant that is greater than or equal to 1 and less than or equal to 63. If not specified, the default is 15.
scale
An integer constant that is greater than or equal to 0 and less than or equal to precision. If not specified, the default is 0.
decimal-character
Specifies the single-byte character constant that is used to delimit the decimal digits in string-expression from the whole part of the number. The character must be a period or comma. If decimal-character is not specified, the decimal point is the default decimal separator character. For more information, see Decimal point.

Digits are truncated from the end if the number of digits to the right of the decimal-character is greater than the scale s. An error is returned if the number of significant digits to the left of the decimal-character (the whole part of the number) in string-expression is greater than precision-scale. The default decimal separator character is not valid in the substring if the decimal-character argument is specified.

Datetime to Decimal

datetime-expression
An expression that returns a value of type DATE, TIME, or TIMESTAMP
precision
An integer constant that is greater than or equal to 1 and less than or equal to 63 that specifies the precision of the result. If not specified, the default for the precision and scale depends on the data type of datetime-expression as follows:
  • Precision is 8 and scale is 0 for DATE. The result is a DECIMAL(8,0) value representing the date as yyyymmdd.
  • Precision is 6 and scale is 0 for a TIME. The result is a DECIMAL(6,0) value representing the time as hhmmss.
  • Precision is 14+tp and scale is tp for a TIMESTAMP(tp). The result is a DECIMAL(14+tp,tp) value representing the timestamp as yyyymmddhhmmss.nnnnnnnnnnnn.
scale
An integer constant that is greater than or equal to 0 and less than or equal to precision. If not specified, the default is 0.

The result is the same number that would result from CAST(datetime-expression AS DECIMAL(precision,scale)). Digits are truncated from the end if the number of digits to the right of the decimal separator character is greater than scale. An error is returned if the number of significant digits to the left of the decimal separator character (the whole part of the number) in datetime-expression is greater than precision - scale.

The result of the function is a decimal number with precision of precision and scale of scale. If the first argument can be null, the result can be null; if the first argument is null, the result is the null value.

Note

Syntax alternatives: The CAST specification should be used to increase the portability of applications when precision is specified. For more information, see CAST specification.

Examples

  • Use the DECIMAL function in order to force a DECIMAL data type (with a precision of 5 and a scale of 2) to be returned in a select-list for the EDLEVEL column (data type = SMALLINT) in the EMPLOYEE table. The EMPNO column should also appear in the select list. 
      SELECT EMPNO, DECIMAL(EDLEVEL,5,2)
    FROM EMPLOYEE
  • Using the PROJECT table, select all of the starting dates (PRSTDATE) that have been incremented by a duration that is specified in a host variable. Assume the host variable PERIOD is of type INTEGER. Then, in order to use its value as a date duration it must be “cast” as DECIMAL(8,0). 
      SELECT PRSTDATE + DECIMAL(:PERIOD,8)
    FROM PROJECT
  • Assume that updates to the SALARY column are input through a window as a character string using comma as a decimal character (for example, the user inputs 21400,50). Once validated by the application, it is assigned to the host variable newsalary which is defined as CHAR(10). 
      UPDATE STAFF
    SET SALARY = DECIMAL(:newsalary, 9, 2, ',')
    WHERE ID = :empid
    The value of SALARY becomes 21400.50.