Getting Started

https://www.sqlflow.cn/gudu-sqlflow-introduction

Let's analyze the following SQL statements to see how to get the data dependencies between tables/views.

Tips:

  • You need to have basic SQL knowledge to understand this doc.

  • No data lineage knowledge is required before you start this doc. You can simply consider data lineage as the data relationship between tables in database.

INSERT INTO deptsal
            (dept_no,
             dept_name,
             salary)
SELECT d.deptno,
       d.dname,
       SUM(e.sal + Nvl(e.comm, 0)) AS sal
FROM   dept d
       left join (SELECT *
                  FROM   emp
                  WHERE  hiredate > DATE '1980-01-01') e
              ON e.deptno = d.deptno
GROUP  BY d.deptno,
          d.dname;

Data of the table deptsal come from the table dept and the table emp. More specifically, following data lineage relationship can be deduced:

  • deptsal.dept_no field comes from dept.deptno

  • deptsal.dept_name field comes from dept.name

  • deptsal.salary field comes from emp.sal and emp.comm

Through Gudu SQLFlow, we can visualize the above data lineage as:

What's next?

PreviousArchitecture OverviewNextSign up a new account

Last updated