An internal table consists of lines that have the same data type. The line of an internal table is a structure. The reference types describe reference variables that refer to instances of classes, interfaces, and runtime data objects.
ABAP has three main data types: elementary types. Elementary types The elementary type is further divided into the fixed-length type and variable-length type. These types consist of: Numeric types: I , F , P. Character types: C , D , N , T. Hexadecimal types: X When you declare a data object that has a fixed-length type, you must specify its length in the variable declaration. Structure types A structure is a group of related data objects. Internal Tables An internal table consists of lines that have the same data type.
Typically, you use an internal table to process tabular data in ABAP programs. An internal table is characterized by: The line type. A table key that uniquely identifies table rows. The table key can be unique or non-unique. The table type e. The components of the local structure dtype have the same names as those of the structure in ABAP Dictionary. We can refer to this structure in ABAP:. You can address the components using the component names from the original structure.
The row type can be any data type from ABAP Dictionary, that is, a data element, a structure, a table type, or the type of a database table. You can also enter a predefined dictionary type directly as the row type, in the same way that you can with a domain. The semantic attributes of the data elements are used for the corresponding components of the internal table in the program.
We can refer to the table type in ABAP:. Before Release 4. It was only possible to refer to flat structures. Structures in programs corresponded to the structures of database tables or structures in ABAP Dictionary. It was, however, possible to refer to individual components of the dictionary type. Complex local data types such as internal tables or deep structures had no equivalent in the ABAP Dictionary.
The solution to this from Release 3. Type groups were based on the include technique, and allowed you to store any type definitions globally in the dictionary by defining them using TYPES statements.
The first statement for the type group pool is always:. This statement allows you to use all the data types and constants defined in the type group pool in your program. You can use multiple type groups in the same program. From Release 6. The data types defined in the type group are used to declare data objects with the DATA statement and the value of the constant is, as the output shows, known in the program.
The following input fields there are relevant to data types: There are three groups on the initial screen: Database Tables and Views. You may refer to the whole structure or to individual components TYPE dbtab TYPE dbtab-comp Note: From Release 6. The output is: 1,23 11 The data types defined in the type group are used to declare data objects with the DATA statement and the value of the constant is, as the output shows, known in the program.
Single-byte integer. Internal only. Two-byte integer. Four-byte integer. Currency field. Currency key. Obsolete data type. Floating point number. Numeric text. Long Character. String of variable length. Byte string of variable length.
Byte string. Long byte string.
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