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mateuszwenus/example.sql

Created April 14, 2014 18:51
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  1. mateuszwenus created this gist Apr 14, 2014.
    81 changes: 81 additions & 0 deletions example.sql
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,81 @@
    create table departments
    (
    dept_id integer primary key,
    dept_name varchar(255)
    );

    create table employees
    (
    emp_id integer primary key,
    emp_name varchar(255),
    dept_id integer,
    constraint emp_dept_fkey foreign key(dept_id) references departments(dept_id)
    );

    create table sales
    (
    sale_id integer primary key,
    sale_value numeric,
    dept_id integer,
    constraint sale_dept_fkey foreign key(dept_id) references departments(dept_id)
    );

    create view v_department_employees as
    select d.dept_id, d.dept_name, count(1) num_employees
    from departments d
    join employees e on d.dept_id = e.dept_id
    group by d.dept_id, d.dept_name;

    create view v_department_sales as
    select d.dept_id, d.dept_name, sum(sale_value) sum_sales
    from departments d
    join sales s on d.dept_id = s.dept_id
    group by d.dept_id, d.dept_name;

    create view v_department_sales_per_employee as
    select de.dept_id, de.dept_name, de.num_employees, ds.sum_sales, ds.sum_sales / de.num_employees sales_per_emp
    from v_department_employees de
    join v_department_sales ds on de.dept_id = ds.dept_id;

    create view v_top_department as
    select dspe.dept_id, dspe.dept_name, dspe.num_employees, dspe.sum_sales, dspe.sales_per_emp
    from v_department_sales_per_employee dspe
    order by sales_per_emp desc
    limit 1;

    insert into departments(dept_id, dept_name) values (1, 'Dept 1');
    insert into departments(dept_id, dept_name) values (2, 'Dept 2');

    insert into employees(emp_id, emp_name, dept_id) values (10, 'Emp 10', 1);
    insert into employees(emp_id, emp_name, dept_id) values (11, 'Emp 11', 1);
    insert into employees(emp_id, emp_name, dept_id) values (20, 'Emp 20', 2);
    insert into employees(emp_id, emp_name, dept_id) values (21, 'Emp 21', 2);
    insert into employees(emp_id, emp_name, dept_id) values (22, 'Emp 22', 2);

    insert into sales(sale_id, sale_value, dept_id) values (1, 1.0, 1);
    insert into sales(sale_id, sale_value, dept_id) values (10, 10.0, 1);
    insert into sales(sale_id, sale_value, dept_id) values (100, 100.0, 1);
    insert into sales(sale_id, sale_value, dept_id) values (2, 2.0, 2);
    insert into sales(sale_id, sale_value, dept_id) values (20, 20.0, 2);

    --
    with recursive view_tree(parent_schema, parent_obj, child_schema, child_obj, ind, ord) as
    (
    select vtu_parent.view_schema, vtu_parent.view_name,
    vtu_parent.table_schema, vtu_parent.table_name,
    '', array[row_number() over (order by view_schema, view_name)]
    from information_schema.view_table_usage vtu_parent
    where vtu_parent.view_schema = 'public' and vtu_parent.view_name = 'v_top_department'
    union all
    select vtu_child.view_schema, vtu_child.view_name,
    vtu_child.table_schema, vtu_child.table_name,
    vtu_parent.ind || ' ',
    vtu_parent.ord || (row_number() over (order by view_schema, view_name))
    from view_tree vtu_parent, information_schema.view_table_usage vtu_child
    where vtu_child.view_schema = vtu_parent.child_schema
    and vtu_child.view_name = vtu_parent.child_obj
    )
    select tree.ind || tree.parent_schema || '.' || tree.parent_obj
    || ' depends on ' || tree.child_schema || '.' || tree.child_obj txt, tree.ord
    from view_tree tree
    order by ord;