Introduction to Process Language › Data Types

Data Types

A data type is the internal representation of data. Data referenced by CA ADS process statements must be predefined in the data dictionary using IDD alone or IDD and the DDL compiler. The data types supported by CA ADS are described below. Examples of each data type are outlined later in this chapter.

Note: CA ADS does not support edited data numeric fields. Therefore, PICTURE clauses on elements in records used in CA ADS dialogs cannot include edit characters such as $, Z, period, comma, or +.

For more information about the correlation between CA ADS data types and SQL data types, see the CA IDMS SQL Reference Guide and the CA IDMS SQL Programming Guide.

Binary

Binary data fields are 1- to 18-digit signed integer data fields. The left-most bit in a binary field is zero for a positive integer and one for a negative integer. The remainder of the binary field contains the numeric value. A negative value is stored in twos complement form.

The following table describes the characteristics of binary data fields and shows how each type of binary field is defined in the data dictionary.

EBCDIC

EBCDIC data fields are data fields containing any value in the EBCDIC collating sequence (hexadecimal '00' through 'FF').

The following table describes the characteristics of EBCDIC data field and shows how it is defined in the data dictionary.

Floating Point

A floating point data field is a numeric data field whose value is expressed as a mantissa, which represents the number, and an exponent (characteristic), which determines the actual decimal position of the number. The value of a floating point data field is the product of the mantissa, and ten raised to the power of the characteristic. A 1- to 16-digit mantissa can be used.

The following table describes the characteristics of floating point data fields and shows how each field is defined in the data dictionary.

Notes:

• 1 To display data field values on a map, assign them to a floating point display data field, or, if small enough, to a decimal or binary field.
• 2 The left-most byte contains the sign of the mantissa and the characteristic. The last 3 or 7 bytes contain the binary representation of the mantissa. Either 7 or 17 decimal digits are allowed.
• 3 Display floating point data fields are in a displayable format. When used in calculations, display floating point fields are converted to equivalent internal floating point values.

Group

Group data fields, including record names, contain subordinate data fields. A group data field references the storage of all subordinate data fields without consideration of their data types. A group data field has no PICTURE or USAGE clauses.

Multibit Binary

Multibit data fields are binary data fields. At runtime, the data fields contain either a 0 or 1 for each character.

The following table describes the characteristics of a multibit binary field and shows how the field is defined in the data dictionary.

Packed Decimal

Packed decimal numeric data fields occupy a half byte of storage per digit. The sign of the number (hexadecimal C, for positive, D for negative, and F for no sign) is stored in the four low-order bits of the rightmost byte. S is used only when the field is signed.

If a packed decimal field is defined with an even number of digits, the field is considered to have one extra digit to the left of the decimal point. For example, a packed decimal field with a picture of 9(4)V99 is considered to have a picture of 9(5)V99.

A packed decimal field with a picture of 9(4)V99 or S9(4)V99 occupies a half byte for the sign and a half byte for each digit, totaling 3.5 bytes. Four bytes are reserved for this field, adding an extra digit to the left of the decimal point.

The following table describes the characteristics of a packed decimal data field and shows how the field is defined in the data dictionary.

Zoned Decimal

Zoned decimal numeric data fields occupy one byte of storage per digit. The sign of the number (hexadecimal C for positive, D for negative, F for unsigned positive) is stored in the four high-order bits of the rightmost digit. S is used only when the field is signed.

The following table describes the characteristics of a zoned decimal data field and how the field is defined in the data dictionary.

Examples of Data Types

The following table illustrates the definition, use, and internal representation of the different data types.

Note:

¹ If no USAGE clause is provided, the default usage is DISPLAY.

² A blank space = a blank (X'40') in internal representations.