文件名称：SQL:连接的类型-复杂查询技术-连接
文件大小：671KB
文件格式：PPT
更新时间：2024-05-15 15:58:11
sql
SQL:1999连接的类型 Cross joins Natural joins JOIN table USING column_name JOIN table ON table1.column_name = table2.column_name LEFT/RIGHT/FULL OUTER 从两个表中返回笛卡尔乘积 基于相同的列名连接两个表 执行一个基于列名的等值连接 执行一个基于在 ON 子句中的条件的等值连接 * Types of Joins The Oracle9i database offers join syntax that is SQL: 1999 compliant. Prior to the 9i release, the join syntax was different from the ANSI standards. The new SQL: 1999 compliant join syntax does not offer any performance benefits over the Oracle proprietary join syntax that existed in prior releases. Instructor Note Do not get into details of all the types of joins now. Explain each join one by one, as is done in the following slides.