关系代数符号：σ π ⋈ ⟗ ⟕ ⟖ × ÷ ∪ ∩ −

显示效果：

对应的代码：

$\sigma_{sno = 1}(Student)$
σ~sno=1~(Student)
$\sigma_{sno = 1 \wedge sage >18 \vee ssex="F"}(Student)$
σ~sno=1∧sage>18∨ssex="F"~ (Student)
$\Pi_{sno,cno}(Student)$
π~sno,cno~ (Student)
$Student \Join SC$
$Student \bowtie SC$
Student⋈SC
$Student \underset{Student.Sno=SC.Sno}\Join  SC$
Student ⟗ SC
Student ⟕ SC
Student ⟖ SC
$Student \times SC$
Student × SC
$SC \div K$
SC ÷ K
$R \cup S$
R∪S
$R \cap S$
R∩S
$R - S$
R−S
$\Pi_{Sname}(\Pi_{sno}(\sigma_{Cpno='5'}(Course)\Join SC)\Join \Pi_{Sno,Sname}(Student))$
π~Sname~ (π~sno~ (σ~Cpno=′5′~(Course) ⋈ SC) ⋈ π ~Sno,Sname~ (Student))