Data types
IMS™ supports data types from SQL.
The smallest unit of data that can be manipulated in SQL is called a value. How values are interpreted depends on the data type of their source. The sources of values are:
- Columns
- Constants
- Expressions
- Variables (such as host variables and parameter markers)
The following image shows the built-in data types that IMS supports.
Figure 1. Built-in
data types supported by IMS
Important:
- XML, CLOB, BOOLEAN, FLOAT, DOUBLE, and fixed-length binary data types are supported only for Java™ application programs.
- Fixed-length binary data type is supported for COBOL and .NET applications for retrieval and parameter marker use only.
- Nulls
All data types include the null value. Distinct from all non-null values, the null value is a special value that denotes the absence of a (non-null) value. - Numbers
The numeric data types are categorized as exact numerics: binary integer and decimal; and approximate numerics: floating-point - Character strings
A character string is a sequence of bytes. The length of the string is the number of bytes in the sequence. If the length is zero, the value is called the empty string. The empty string should not be confused with the null value. - Datetime values
Datetime values are neither strings nor numbers. Nevertheless, datetime values can be used in certain arithmetic and string operations and are compatible with certain strings.
Related concepts: