Data Types

A data type is a set of values that share processing characteristics. For example, the set of all integers is a data type. Every column, local variable, parameter, and host variable has an associated data type.

Data Types and Value Sets

The data type limits the set of values that can occur in the column, local variable, parameter, or host variable. The data type also determines the operations that can be performed on values in the column, local variable, parameter, or host variable.

You associate a data type with the following:

A column when you define the column
An SQL routine local variable when you define the local variable
An SQL-invoked routine parameter when you define the parameter
A host variable when you declare the host variable

More Information

For more information about defining columns, see CREATE TABLE and ALTER TABLE.
For more information about declaring host variables, see Host Variables.
For more information about declaring local variables, see Local Variables.
For more information about declaring routine-parameters, see Routine Parameters.

Categories of Data Types

CA IDMS supports the following data types:

Category	Data types
Approximate numeric	DOUBLE PRECISION FLOAT REAL
Binary	BINARY
Character string	CHARACTER VARCHAR (or CHAR VARYING)
Date/time	DATE TIME TIMESTAMP
Exact numeric	DECIMAL INTEGER LONGINT (or BIGINT) NUMERIC SMALLINT UNSIGNED DECIMAL UNSIGNED NUMERIC
Graphics character string	GRAPHIC VARGRAPHIC
XML data	XML

More Information

For more information about a description of the XML data type, see XML Data Type and XML Values.
For more information about a description of all the other data types, see Expansion of Data-type.

Determining the Data Type of a Value

The data type of a value in a column, host variable, local variable, or parameter is the data type of the column, host variable, local variable or routine parameter. For example, every value in a column with a data type of INTEGER has a data type INTEGER.

The literal used to represent a value must be appropriate for the data type of the value. For example, 983 represents a numeric value; '983' represents a character value.

Note: For more information about literals, see Literals.

Data Types Effect on Processing

The data type of a value determines:

Columns, local variables, parameters, and host variables to which it can be assigned
Values with which it can be compared
Operations where it can be used
Results of operations where it is combined with values of other data types
Its internal representation and storage requirements

More information:

ALTER TABLE

CREATE TABLE

Local Variables

Expansion of Data-type

Host Variables

Routine Parameters