The derived relational algebra operators are widely used in the relational database query languages.
关系代数的派生算子在关系数据库查询语言中得到了广泛应用。
Traditional relational database query language SQL is designed for relational tables, and not suitable for XML or GML semistructured data;
传统的关系数据库查询语言SQL是针对平面的二维关系数据而设计的，并不适合XML/GML半结构化数据的查询；
Based on this model, this paper constructs two different kinds of medium relational database query languages: medium relational calculus and medium relational algebra.
给出了中介关系数据模型，在此基础上构造了两类不同的中介关系数据库查询语言：中介关系演算和中介关系代数。
Select Relational Database Query (SQL) under the enterprise section (as shown in following Figure 3), then click on the Next button to proceed
选择enterprise部分下面的Relational Database Query (SQL)（见图3），然后单击Next按钮继续
Select Relational Database Query (SQL) under the enterprise section (as shown in following Figure 3), then click on the Next button to proceed
选择enterprise部分下面的Relational Database Query (SQL)（见图3），然后单击Next按钮继续
应用推荐