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Manipulating Individual ElementsFaraway you have manipulated an entire collection. Within the SQL, to manipulate the individual elements of the collection, and then use the operator TABLE. The operand of TABLE is a subquery which returns a single column value for you to manipulate. That the value is the nested table or the varray.In the illustration below, you add a row to the History Department nested table stored in the column courses:BEGININSERT INTOTABLE(SELECT courses FROM department WHERE name = ’History’)VALUES(3340, ’Modern China’, 4);END;In the next illustration, you revise the number of credits for two courses offered by the Psychology Department:DECLAREadjustment INTEGER DEFAULT 1;BEGINUPDATE TABLE(SELECT courses FROM departmentWHERE name = ’Psychology’)SET credits = credits + adjustmentWHERE course_no IN (2200, 3540);END;In the following illustration, you retrieve the number and the title of a specific course offered by the History Department:DECLAREmy_course_no NUMBER(4);my_title VARCHAR2(35);BEGINSELECT course_no, title INTO my_course_no, my_titleFROM TABLE(SELECT courses FROM departmentWHERE name = ’History’)WHERE course_no = 3105;...END;In the next illustration, you delete all 5-credit courses offered by the English Department:BEGINDELETE TABLE(SELECT courses FROM departmentWHERE name = ’English’)WHERE credits = 5;END;In the following illustration, you recover the title and cost of the Maintenance Department’s fourth project from the varray column projects:DECLAREmy_cost NUMBER(7,2);my_title VARCHAR2(35);BEGINSELECT cost, title INTO my_cost, my_titleFROM TABLE(SELECT projects FROM departmentWHERE dept_id = 50)WHERE project_no = 4;...END;Presently, you cannot reference the individual elements of a varray in an UPDATE, INSERT, or DELETE statement. And hence, you should use the PL/SQL procedural statements. In the illustration below, the stored procedure add_project inserts a new project into the department’s project list at a given position a shown:CREATE PROCEDURE add_project (dept_no IN NUMBER,new_project IN Project,position IN NUMBER) ASmy_projects ProjectList;BEGINSELECT projects INTO my_projects FROM departmentWHERE dept_no = dept_id FOR UPDATE OF projects;my_projects.EXTEND; -- make room for new project/* Move varray elements forward. */FOR i IN REVERSE position..my_projects.LAST - 1 LOOPmy_projects(i + 1) := my_projects(i);END LOOP;my_projects(position) := new_project; -- add new projectUPDATE department SET projects = my_projectsWHERE dept_no = dept_id;END add_project;The stored procedure updates below for a given project is:CREATE PROCEDURE update_project (dept_no IN NUMBER,proj_no IN NUMBER,new_title IN VARCHAR2 DEFAULT NULL,new_cost IN NUMBER DEFAULT NULL) ASmy_projects ProjectList;BEGINSELECT projects INTO my_projects FROM departmentWHERE dept_no = dept_id FOR UPDATE OF projects;/* Find project, update it, then exit loop immediately. */FOR i IN my_projects.FIRST..my_projects.LAST LOOPIF my_projects(i).project_no = proj_no THENIF new_title IS NOT NULL THENmy_projects(i).title := new_title;END IF;IF new_cost IS NOT NULL THENmy_projects(i).cost := new_cost;END IF;EXIT;END IF;END LOOP;UPDATE department SET projects = my_projectsWHERE dept_no = dept_id;END update_project;
Predicate - SQL Consider the declarative sentence-a proposition-that is used to introduce this topic: "Student S1, named Anne, is enrolled on course C1." Recall that th
Truth Tables: However in propositional logic - here we are restricted to expressing sentences and where the propositions are true or false - so we can check where a particular
COSMOZOI C THEORY - Richter (1865) proposed the cosmozoic theory that says that life came by spores (cosmozoa) or other particles from other planets on the earth.
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At times, Brewbean's has changed the id number for existing products. In the past, they have had to add a new product row with the new id to the BB_PRODUCT table, modify all the co
Change Sql file into CSV for product registration on Magento Project Description: I have a set of files that are in Sql format and could like for a developer to help me with
Package STANDARD The package named STANDARD defines the PL/SQL atmosphere. The package specification globally declares the exceptions, types, and subprograms that are available
Authorisations - Privileges As relational theory is silent on the issue of authorisation, it offers nothing with which SQL's vast edifice in support of what it calls privilege
Parameter and Keyword Description: cursor_variable_name: This identifies a cursor variable or the parameter formerly declared within the present scope. host_cursor_va
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