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Rules for using NEXTVAL and CURRVAL You can use NEXTVAL and CURRVAL in the following contexts:The SELECT list of a SELECT statement that is not part of a subqueryThe SELECT list of a subquery in an INSERT statementThe VALUES clause of an INSERT statementThe SET clause of an UPDATE statement You cannot use NEXTVAL and CURRVAL in the following context: The SELECT list of a viewA SELECT statement w..

Rules for using NEXTVAL and CURRVAL You can use NEXTVAL and CURRVAL in the following contexts:The SELECT list of a SELECT statement that is not part of a subqueryThe SELECT list of a subquery in an INSERT statementThe VALUES clause of an INSERT statementThe SET clause of an UPDATE statement You cannot use NEXTVAL and CURRVAL in the following context: The SELECT list of a viewA SELECT statement w..

Can automatically generate unique numbers Is a sharable object Can be used to create a primary key value Replaces application code Speeds up the efficiency of accessing sequence values when cached in memeory SyntaxCREATE SEQUENCE sequence [INCREMENT BY n] [START WITH n] [{MAXVALUE n | NOMAXVALUE}] [{MINVALUE n | NOMAXVALUE}] [{CYCLE | NOCYCLE}] [{CACHE n | NOCACHE}]; default increment value : 1 ..

Can automatically generate unique numbers Is a sharable object Can be used to create a primary key value Replaces application code Speeds up the efficiency of accessing sequence values when cached in memeory SyntaxCREATE SEQUENCE sequence [INCREMENT BY n] [START WITH n] [{MAXVALUE n | NOMAXVALUE}] [{MINVALUE n | NOMAXVALUE}] [{CYCLE | NOCYCLE}] [{CACHE n | NOCACHE}]; default increment value : 1 ..

CREATE OR REPLACE VIEW empvu10 (employee_number, employee_name, job_title) AS SELECT employee_id, last_name,job_id FROM employees WHERE department_id = 10 WITH READ ONLY; DROP VIEW view_name;

CREATE OR REPLACE VIEW empvu10 (employee_number, employee_name, job_title) AS SELECT employee_id, last_name,job_id FROM employees WHERE department_id = 10 WITH READ ONLY; DROP VIEW view_name;

CREATE OR REPLACE VIEW empvu20 AS SELECT * FROM employees WHERE department_id = 20 WITH CHECK OPTION CONSTRAINT empvu20_ck;No rows are updated because if the department number were to change to 10, the view would no longer be able to see that employee. With the WITH CHECK OPTION clause, therefore, the view can see only employees in department 20 and doesn't allow the department number for those ..

CREATE OR REPLACE VIEW empvu20 AS SELECT * FROM employees WHERE department_id = 20 WITH CHECK OPTION CONSTRAINT empvu20_ck;No rows are updated because if the department number were to change to 10, the view would no longer be able to see that employee. With the WITH CHECK OPTION clause, therefore, the view can see only employees in department 20 and doesn't allow the department number for those ..

DML operation on simple viewCannot remove or modify a row if the view contains the following: - Group function - A GROUP BY clause - The DISTINCT keyword - The pseudocolumn ROWNUM keyword - columns defined by expressions (only modify) Cannot add data through a view if the view includes - Group function - A GROUP BY clause - The DISTINCT keyword - The pseudocolumn ROWNUM keyword - columns defined..

DML operation on simple viewCannot remove or modify a row if the view contains the following: - Group function - A GROUP BY clause - The DISTINCT keyword - The pseudocolumn ROWNUM keyword - columns defined by expressions (only modify) Cannot add data through a view if the view includes - Group function - A GROUP BY clause - The DISTINCT keyword - The pseudocolumn ROWNUM keyword - columns defined..