信息技术.数据库语言.SQL.第2部分:基本原则(SQL/基本原则)

[中文适用范围]： 本部分ISO/IEC 9075定义了SQL数据的数据结构和基本操作。它提供了创建、访问、维护、控制和保护SQL数据的功能能力。 本部分ISO/IEC 9075规定了数据库语言的语法和语义： — 用于指定和修改SQL数据的结构和完整性约束。 — 用于声明和调用SQL数据和游标的操作。 — 用于声明数据库语言过程。 — 用于将SQL语句嵌入到其他编程语言（宿主语言）编写的编译单元中。 — 用于在宿主语言中派生等效的编译单元。在该等效编译单元中，每个嵌入的SQL语句被替换为宿主语言中的一个或多个语句，其中一些调用SQL外部调用过程，执行时具有与执行SQL语句相同的效果。 — 用于直接调用SQL语句。 — 支持动态准备和执行SQL语句。 本部分ISO/IEC 9075为SQL实现之间的数据定义和编译单元的可移植性提供了工具。 本部分ISO/IEC 9075为SQL实现之间的互连提供了工具。 本部分ISO/IEC 9075的实现可以存在于支持应用编程语言、终端用户查询语言、报表生成系统、数据字典系统、程序库系统、分布式通信系统以及各种数据库设计、数据管理和性能优化工具的环境中。 [外文原描述]： ISO/IEC 9075-2:2016 defines the data structures and basic operations on SQL-data. It provides functional capabilities for creating, accessing, maintaining, controlling, and protecting SQL-data. ISO/IEC 9075-2:2016 specifies the syntax and semantics of a database language: - For specifying and modifying the structure and the integrity constraints of SQL-data. - For declaring and invoking operations on SQL-data and cursors. - For declaring database language procedures. - For embedding SQL-statements in a compilation unit that is otherwise written in a particular programming language (host language). - For deriving an equivalent compilation unit in the host language. In that equivalent compilation unit, each which invoke an SQL externally-invoked procedure that, when executed, has an effect equivalent to exe-cuting the SQL-statement. - For direct invocation of SQL-statements. - To support dynamic preparation and execution of SQL-statements. ISO/IEC 9075-2:2016 provides a vehicle for portability of data definitions and compilation units between SQL-implementations. ISO/IEC 9075-2:2016 provides a vehicle for interconnection of SQL-implementations. Implementations of this ISO/IEC 9075-2:2016 can exist in environments that also support application program-ming languages, end-user query languages, report generator systems, data dictionary systems, program library systems, and distributed communication systems, as well as various tools for database design, data administration, and performance optimization.