This chapter describes the Data Manipulation Language (DML). The Elementary Data Language discussed in Chap. 2 provides a useful repertoire of operations on network structure. Like an assembly language, however, it is tedious to write queries in the Elementary Data Language. To provide a user with a higher-level language facility, we have designed a DML on top of the Elementary Data Language. The DML defines rules for composition of Elementary Data Operations. The design goals of DML are summarized as:
— Easy to write queries.
— Aid the user to construct efficient queries.
— Precise definition of each DML statement.
KeywordsRecord Statement Link Statement Link Operator Link Type Record Type
Unable to display preview. Download preview PDF.
© Springer-Verlag Tokyo 1990