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ABAP CDS - General Syntax Rules

The general syntax rules for the CDS DDL and CDS DCL for defining CDS objects in ABAP CDS are as follows:

• Keywords

• Keywords must be all uppercase, all lowercase, or in lowercase with an uppercase initial letter. Other mixes of uppercase and lowercase are not allowed.

• Names

• Names are not case-sensitive.

• A name must contain at least 2 characters but no more than 30 characters.

• A name can consist of letters, numbers, underscores (_), and slashes (/).

• A name must start with a letter, slash character, or underscore. Underscores are recommended as the naming convention for CDS associations.

• The separator for names with multiple parts is a period (.). Names with multiple parts can be paths, columns with a prefixed data source, and structured annotations.

• The following CDS keywords cannot be used as names:
  
  ALL, AND, AS, ASSOCIATION, AVG, CASE, CAST, COUNT, CROSS, DISTINCT, EXISTS, EXTEND, EXTENSION, FROM, FULL, GROUP, HAVING, INNER, JOIN, KEY, LEFT, MAX, MIN, NOT, NULL, ON, OR, ORDER, RIGHT, SELECT, SUM, UNION, VIEW, WHEN, WHERE

• Literals

• Numeric literals must always be specified in full and a decimal point (.) used as a decimal separator if necessary.

• Character literals are enclosed in single quotation marks (').

• Comments

• Two forward slashes (//) introduce a comment, which continues until the end of the line.

• Comments within lines or that span multiple lines are enclosed by the characters /* and */.

• Separators

• Statements can be closed using a semicolon (;). Sometimes this is mandatory.

• Protected words

• Certain keywords are protected and cannot be used as self-defined names. The reserved names that cannot be used are specified in the database table TRESE.

Other versions: 7.31 | 7.40 | 7.54

Notes

• The closing semicolon after a statement is sometimes optional because one piece of CDS source code can currently only contain a single statement.

• In DDL source code for CDS data definitions and DCL source code for CDS roles, as well as two slashes, two dashes (--) can also be used to introduce a comment. Slashes (//), however, are the recommended method. Two dashes are not allowed in DDLA source code for annotation definitions and in DDLX source code for metadata extensions.

Examples

• SELECT, select, and Select are all valid ways of specifying a keyword. seLect and SeLect, on the other hand, produce syntax errors.

• MYVIEW, myview, and myView all identify the same operand.

• 0.5 is a valid numeric literal, but .5 is not.