About the Examples Used in this Guide v12

The examples in this guide are shown in the type and background illustrated below.

Examples and output from examples are shown in fixed-width, white font on a black background.

The examples use the sample tables, dept, emp, and jobhist, created and loaded when Advanced Server is installed.

The tables and programs in the sample database can be re-created at any time by executing the following script:

/usr/edb/asxx/share/pg-sample.sql

where xx is the Advanced Server version number.

In addition there is a script in the same directory containing the database objects created using syntax compatible with Oracle databases. This script file is edb-sample.sql.

The script:

  • Creates the sample tables and programs in the currently connected database.
  • Grants all permissions on the tables to the PUBLIC group.

The tables and programs will be created in the first schema of the search path in which the current user has permission to create tables and procedures. You can display the search path by issuing the command:

SHOW SEARCH_PATH;

You can use PSQL commands to modify the search path.

Sample Database Description

The sample database represents employees in an organization. It contains three types of records: employees, departments, and historical records of employees.

Each employee has an identification number, name, hire date, salary, and manager. Some employees earn a commission in addition to their salary. All employee-related information is stored in the emp table.

The sample company is regionally diverse, so it tracks the locations of its departments. Each company employee is assigned to a department. Each department is identified by a unique department number and a short name. Each department is associated with one location. All department-related information is stored in the dept table.

The company also tracks information about jobs held by the employees. Some employees have been with the company for a long time and have held different positions, received raises, switched departments, etc. When a change in employee status occurs, the company records the end date of the former position. A new job record is added with the start date and the new job title, department, salary, and the reason for the status change. All employee history is maintained in the jobhist table.

The following is the pg-sample.sql script:

SET datestyle TO 'iso, dmy';

--
--  Script that creates the 'sample' tables, views
--  functions, triggers, etc.
--
--  Start new transaction - commit all or nothing
--
BEGIN;
--
--  Create and load tables used in the documentation examples.
--
--  Create the 'dept' table
--
CREATE TABLE dept (
    deptno          NUMERIC(2) NOT NULL CONSTRAINT dept_pk PRIMARY KEY,
    dname           VARCHAR(14) CONSTRAINT dept_dname_uq UNIQUE,
    loc             VARCHAR(13)
);
--
--  Create the 'emp' table
--
CREATE TABLE emp (
    empno           NUMERIC(4) NOT NULL CONSTRAINT emp_pk PRIMARY KEY,
    ename           VARCHAR(10),
    job             VARCHAR(9),
    mgr             NUMERIC(4),
    hiredate        DATE,
    sal             NUMERIC(7,2) CONSTRAINT emp_sal_ck CHECK (sal > 0),
    comm            NUMERIC(7,2),
    deptno          NUMERIC(2) CONSTRAINT emp_ref_dept_fk
                        REFERENCES dept(deptno)
);
--
--  Create the 'jobhist' table
--
CREATE TABLE jobhist (
    empno           NUMERIC(4) NOT NULL,
    startdate       TIMESTAMP(0) NOT NULL,
    enddate         TIMESTAMP(0),
    job             VARCHAR(9),
    sal             NUMERIC(7,2),
    comm            NUMERIC(7,2),
    deptno          NUMERIC(2),
    chgdesc         VARCHAR(80),
    CONSTRAINT jobhist_pk PRIMARY KEY (empno, startdate),
    CONSTRAINT jobhist_ref_emp_fk FOREIGN KEY (empno)
        REFERENCES emp(empno) ON DELETE CASCADE,
    CONSTRAINT jobhist_ref_dept_fk FOREIGN KEY (deptno)
        REFERENCES dept (deptno) ON DELETE SET NULL,
    CONSTRAINT jobhist_date_chk CHECK (startdate <= enddate)
);
--
--  Create the 'salesemp' view
--
CREATE OR REPLACE VIEW salesemp AS
    SELECT empno, ename, hiredate, sal, comm FROM emp WHERE job = 'SALESMAN';
--
--  Sequence to generate values for function 'new_empno'.
--
CREATE SEQUENCE next_empno START WITH 8000 INCREMENT BY 1;
--
--  Issue PUBLIC grants
--
--GRANT ALL ON emp TO PUBLIC;
--GRANT ALL ON dept TO PUBLIC;
--GRANT ALL ON jobhist TO PUBLIC;
--GRANT ALL ON salesemp TO PUBLIC;
--GRANT ALL ON next_empno TO PUBLIC;
--
--  Load the 'dept' table
--
INSERT INTO dept VALUES (10,'ACCOUNTING','NEW YORK');
INSERT INTO dept VALUES (20,'RESEARCH','DALLAS');
INSERT INTO dept VALUES (30,'SALES','CHICAGO');
INSERT INTO dept VALUES (40,'OPERATIONS','BOSTON');
--
--  Load the 'emp' table
--
INSERT INTO emp VALUES (7369,'SMITH','CLERK',7902,'17-DEC-80',800,NULL,20);
INSERT INTO emp VALUES (7499,'ALLEN','SALESMAN',7698,'20-FEB-81',1600,300,30);
INSERT INTO emp VALUES (7521,'WARD','SALESMAN',7698,'22-FEB-81',1250,500,30);
INSERT INTO emp VALUES (7566,'JONES','MANAGER',7839,'02-APR-81',2975,NULL,20);
INSERT INTO emp VALUES (7654,'MARTIN','SALESMAN',7698,'28-SEP-81',1250,1400,30);
INSERT INTO emp VALUES (7698,'BLAKE','MANAGER',7839,'01-MAY-81',2850,NULL,30);
INSERT INTO emp VALUES (7782,'CLARK','MANAGER',7839,'09-JUN-81',2450,NULL,10);
INSERT INTO emp VALUES (7788,'SCOTT','ANALYST',7566,'19-APR-87',3000,NULL,20);
INSERT INTO emp VALUES (7839,'KING','PRESIDENT',NULL,'17-NOV-81',5000,NULL,10);
INSERT INTO emp VALUES (7844,'TURNER','SALESMAN',7698,'08-SEP-81',1500,0,30);
INSERT INTO emp VALUES (7876,'ADAMS','CLERK',7788,'23-MAY-87',1100,NULL,20);
INSERT INTO emp VALUES (7900,'JAMES','CLERK',7698,'03-DEC-81',950,NULL,30);
INSERT INTO emp VALUES (7902,'FORD','ANALYST',7566,'03-DEC-81',3000,NULL,20);
INSERT INTO emp VALUES (7934,'MILLER','CLERK',7782,'23-JAN-82',1300,NULL,10);
--
--  Load the 'jobhist' table
--
INSERT INTO jobhist VALUES (7369,'17-DEC-80',NULL,'CLERK',800,NULL,20,'New Hire');
INSERT INTO jobhist VALUES (7499,'20-FEB-81',NULL,'SALESMAN',1600,300,30,'New Hire');
INSERT INTO jobhist VALUES (7521,'22-FEB-81',NULL,'SALESMAN',1250,500,30,'New Hire');
INSERT INTO jobhist VALUES (7566,'02-APR-81',NULL,'MANAGER',2975,NULL,20,'New Hire');
INSERT INTO jobhist VALUES (7654,'28-SEP-81',NULL,'SALESMAN',1250,1400,30,'New Hire');
INSERT INTO jobhist VALUES (7698,'01-MAY-81',NULL,'MANAGER',2850,NULL,30,'New Hire');
INSERT INTO jobhist VALUES (7782,'09-JUN-81',NULL,'MANAGER',2450,NULL,10,'New Hire');
INSERT INTO jobhist VALUES (7788,'19-APR-87','12-APR-88','CLERK',1000,NULL,20,'New Hire');
INSERT INTO jobhist VALUES (7788,'13-APR-88','04-MAY-89','CLERK',1040,NULL,20,'Raise');
INSERT INTO jobhist VALUES (7788,'05-MAY-90',NULL,'ANALYST',3000,NULL,20,'Promoted to Analyst');
INSERT INTO jobhist VALUES (7839,'17-NOV-81',NULL,'PRESIDENT',5000,NULL,10,'New Hire');
INSERT INTO jobhist VALUES (7844,'08-SEP-81',NULL,'SALESMAN',1500,0,30,'New Hire');
INSERT INTO jobhist VALUES (7876,'23-MAY-87',NULL,'CLERK',1100,NULL,20,'New Hire');
INSERT INTO jobhist VALUES (7900,'03-DEC-81','14-JAN-83','CLERK',950,NULL,10,'New Hire');
INSERT INTO jobhist VALUES (7900,'15-JAN-83',NULL,'CLERK',950,NULL,30,'Changed to Dept 30');
INSERT INTO jobhist VALUES (7902,'03-DEC-81',NULL,'ANALYST',3000,NULL,20,'New Hire');
INSERT INTO jobhist VALUES (7934,'23-JAN-82',NULL,'CLERK',1300,NULL,10,'New Hire');
--
--  Populate statistics table and view (pg_statistic/pg_stats)
--
ANALYZE dept;
ANALYZE emp;
ANALYZE jobhist;
--
--  Function that lists all employees' numbers and names
--  from the 'emp' table using a cursor.
--
CREATE OR REPLACE FUNCTION list_emp() RETURNS VOID
AS $$
DECLARE
    v_empno             NUMERIC(4);
    v_ename             VARCHAR(10);
    emp_cur CURSOR FOR
        SELECT empno, ename FROM emp ORDER BY empno;
BEGIN
    OPEN emp_cur;
    RAISE INFO 'EMPNO ENAME';
    RAISE INFO '----- -------';
    LOOP
        FETCH emp_cur INTO v_empno, v_ename;
        EXIT WHEN NOT FOUND;
        RAISE INFO '% %', v_empno, v_ename;
    END LOOP;
    CLOSE emp_cur;
    RETURN;
END;
$$ LANGUAGE 'plpgsql';
--
--  Function that selects an employee row given the employee
--  number and displays certain columns.
--
CREATE OR REPLACE FUNCTION select_emp (
    p_empno         NUMERIC
) RETURNS VOID
AS $$
DECLARE
    v_ename         emp.ename%TYPE;
    v_hiredate      emp.hiredate%TYPE;
    v_sal           emp.sal%TYPE;
    v_comm          emp.comm%TYPE;
    v_dname         dept.dname%TYPE;
    v_disp_date     VARCHAR(10);
BEGIN
    SELECT INTO
        v_ename, v_hiredate, v_sal, v_comm, v_dname
        ename, hiredate, sal, COALESCE(comm, 0), dname
        FROM emp e, dept d
        WHERE empno = p_empno
          AND e.deptno = d.deptno;
    IF NOT FOUND THEN
        RAISE INFO 'Employee % not found', p_empno;
        RETURN;
    END IF;
    v_disp_date := TO_CHAR(v_hiredate, 'MM/DD/YYYY');
    RAISE INFO 'Number    : %', p_empno;
    RAISE INFO 'Name      : %', v_ename;
    RAISE INFO 'Hire Date : %', v_disp_date;
    RAISE INFO 'Salary    : %', v_sal;
    RAISE INFO 'Commission: %', v_comm;
    RAISE INFO 'Department: %', v_dname;
    RETURN;
EXCEPTION
    WHEN OTHERS THEN
        RAISE INFO 'The following is SQLERRM : %', SQLERRM;
        RAISE INFO 'The following is SQLSTATE: %', SQLSTATE;
        RETURN;
END;
$$ LANGUAGE 'plpgsql';
--
--  A RECORD type used to format the return value of
--  function, 'emp_query'.
--
CREATE TYPE emp_query_type AS (
    empno           NUMERIC,
    ename           VARCHAR(10),
    job             VARCHAR(9),
    hiredate        DATE,
    sal             NUMERIC
);
--
--  Function that queries the 'emp' table based on
--  department number and employee number or name. Returns
--  employee number and name as INOUT parameters and job,
--  hire date, and salary as OUT parameters. These are
--  returned in the form of a record defined by
--  RECORD type, 'emp_query_type'.
--
CREATE OR REPLACE FUNCTION emp_query (
    IN p_deptno         NUMERIC,
    INOUT p_empno       NUMERIC,
    INOUT p_ename       VARCHAR,
    OUT p_job           VARCHAR,
    OUT p_hiredate      DATE,
    OUT p_sal           NUMERIC
)
AS $$
BEGIN
    SELECT INTO
        p_empno, p_ename, p_job, p_hiredate, p_sal
        empno, ename, job, hiredate, sal
        FROM emp
        WHERE deptno = p_deptno
          AND (empno = p_empno
           OR ename = UPPER(p_ename));
END;
$$ LANGUAGE 'plpgsql';
--
--  Function to call 'emp_query_caller' with IN and INOUT
--  parameters. Displays the results received from INOUT and
--  OUT parameters.
--
CREATE OR REPLACE FUNCTION emp_query_caller() RETURNS VOID
AS $$
DECLARE
    v_deptno       NUMERIC;
    v_empno        NUMERIC;
    v_ename        VARCHAR;
    v_rows         INTEGER;
    r_emp_query    EMP_QUERY_TYPE;
BEGIN
    v_deptno := 30;
    v_empno := 0;
    v_ename := 'Martin';
    r_emp_query := emp_query(v_deptno, v_empno, v_ename);
    RAISE INFO 'Department : %', v_deptno;
    RAISE INFO 'Employee No: %', (r_emp_query).empno;
    RAISE INFO 'Name       : %', (r_emp_query).ename;
    RAISE INFO 'Job        : %', (r_emp_query).job;
    RAISE INFO 'Hire Date  : %', (r_emp_query).hiredate;
    RAISE INFO 'Salary     : %', (r_emp_query).sal;
    RETURN;
EXCEPTION
    WHEN OTHERS THEN
        RAISE INFO 'The following is SQLERRM : %', SQLERRM;
        RAISE INFO 'The following is SQLSTATE: %', SQLSTATE;
        RETURN;
END;
$$ LANGUAGE 'plpgsql';
--
--  Function to compute yearly compensation based on semimonthly
--  salary.
--
CREATE OR REPLACE FUNCTION emp_comp (
    p_sal          NUMERIC,
    p_comm         NUMERIC
) RETURNS NUMERIC
AS $$
BEGIN
    RETURN (p_sal + COALESCE(p_comm, 0)) * 24;
END;
$$ LANGUAGE 'plpgsql';
--
--  Function that gets the next number from sequence, 'next_empno',
--  and ensures it is not already in use as an employee number.
--
CREATE OR REPLACE FUNCTION new_empno() RETURNS INTEGER
AS $$
DECLARE
    v_cnt           INTEGER := 1;
    v_new_empno     INTEGER;
BEGIN
    WHILE v_cnt > 0 LOOP
        SELECT INTO v_new_empno nextval('next_empno');
        SELECT INTO v_cnt COUNT(*) FROM emp WHERE empno = v_new_empno;
    END LOOP;
    RETURN v_new_empno;
END;
$$ LANGUAGE 'plpgsql';
--
--  Function that adds a new clerk to table 'emp'.
--
CREATE OR REPLACE FUNCTION hire_clerk (
    p_ename        VARCHAR,
    p_deptno       NUMERIC
) RETURNS NUMERIC
AS $$
DECLARE
    v_empno        NUMERIC(4);
    v_ename        VARCHAR(10);
    v_job          VARCHAR(9);
    v_mgr          NUMERIC(4);
    v_hiredate     DATE;
    v_sal          NUMERIC(7,2);
    v_comm         NUMERIC(7,2);
    v_deptno       NUMERIC(2);
BEGIN
    v_empno := new_empno();
    INSERT INTO emp VALUES (v_empno, p_ename, 'CLERK', 7782,
        CURRENT_DATE, 950.00, NULL, p_deptno);
    SELECT INTO
        v_empno, v_ename, v_job, v_mgr, v_hiredate, v_sal, v_comm, v_deptno
        empno, ename, job, mgr, hiredate, sal, comm, deptno
        FROM emp WHERE empno = v_empno;
    RAISE INFO 'Department : %', v_deptno;
    RAISE INFO 'Employee No: %', v_empno;
    RAISE INFO 'Name       : %', v_ename;
    RAISE INFO 'Job        : %', v_job;
    RAISE INFO 'Manager    : %', v_mgr;
    RAISE INFO 'Hire Date  : %', v_hiredate;
    RAISE INFO 'Salary     : %', v_sal;
    RAISE INFO 'Commission : %', v_comm;
    RETURN v_empno;
EXCEPTION
    WHEN OTHERS THEN
        RAISE INFO 'The following is SQLERRM : %', SQLERRM;
        RAISE INFO 'The following is SQLSTATE: %', SQLSTATE;
        RETURN -1;
END;
$$ LANGUAGE 'plpgsql';
--
--  Function that adds a new salesman to table 'emp'.
--
CREATE OR REPLACE FUNCTION hire_salesman (
    p_ename        VARCHAR,
    p_sal          NUMERIC,
    p_comm         NUMERIC
) RETURNS NUMERIC
AS $$
DECLARE
    v_empno        NUMERIC(4);
    v_ename        VARCHAR(10);
    v_job          VARCHAR(9);
    v_mgr          NUMERIC(4);
    v_hiredate     DATE;
    v_sal          NUMERIC(7,2);
    v_comm         NUMERIC(7,2);
    v_deptno       NUMERIC(2);
BEGIN
    v_empno := new_empno();
    INSERT INTO emp VALUES (v_empno, p_ename, 'SALESMAN', 7698,
        CURRENT_DATE, p_sal, p_comm, 30);
    SELECT INTO
        v_empno, v_ename, v_job, v_mgr, v_hiredate, v_sal, v_comm, v_deptno
        empno, ename, job, mgr, hiredate, sal, comm, deptno
        FROM emp WHERE empno = v_empno;
    RAISE INFO 'Department : %', v_deptno;
    RAISE INFO 'Employee No: %', v_empno;
    RAISE INFO 'Name       : %', v_ename;
    RAISE INFO 'Job        : %', v_job;
    RAISE INFO 'Manager    : %', v_mgr;
    RAISE INFO 'Hire Date  : %', v_hiredate;
    RAISE INFO 'Salary     : %', v_sal;
    RAISE INFO 'Commission : %', v_comm;
    RETURN v_empno;
EXCEPTION
    WHEN OTHERS THEN
        RAISE INFO 'The following is SQLERRM : %', SQLERRM;
        RAISE INFO 'The following is SQLSTATE: %', SQLSTATE;
        RETURN -1;
END;
$$ LANGUAGE 'plpgsql';
--
--  Rule to INSERT into view 'salesemp'
--
CREATE OR REPLACE RULE salesemp_i AS ON INSERT TO salesemp
DO INSTEAD
    INSERT INTO emp VALUES (NEW.empno, NEW.ename, 'SALESMAN', 7698,
        NEW.hiredate, NEW.sal, NEW.comm, 30);
--
--  Rule to UPDATE view 'salesemp'
--
CREATE OR REPLACE RULE salesemp_u AS ON UPDATE TO salesemp
DO INSTEAD
    UPDATE emp SET empno    = NEW.empno,
                   ename    = NEW.ename,
                   hiredate = NEW.hiredate,
                   sal      = NEW.sal,
                   comm     = NEW.comm
        WHERE empno = OLD.empno;
--
--  Rule to DELETE from view 'salesemp'
--
CREATE OR REPLACE RULE salesemp_d AS ON DELETE TO salesemp
DO INSTEAD
    DELETE FROM emp WHERE empno = OLD.empno;
--
--  After statement-level trigger that displays a message after
--  an insert, update, or deletion to the 'emp' table. One message
--  per SQL command is displayed.
--
CREATE OR REPLACE FUNCTION user_audit_trig() RETURNS TRIGGER
AS $$
DECLARE
    v_action       VARCHAR(24);
    v_text         TEXT;
BEGIN
    IF TG_OP = 'INSERT' THEN
        v_action := ' added employee(s) on ';
    ELSIF TG_OP = 'UPDATE' THEN
        v_action := ' updated employee(s) on ';
    ELSIF TG_OP = 'DELETE' THEN
        v_action := ' deleted employee(s) on ';
    END IF;
    v_text := 'User ' || USER || v_action || CURRENT_DATE;
    RAISE INFO ' %', v_text;
    RETURN NULL;
END;
$$ LANGUAGE 'plpgsql';
CREATE TRIGGER user_audit_trig
    AFTER INSERT OR UPDATE OR DELETE ON emp
    FOR EACH STATEMENT EXECUTE PROCEDURE user_audit_trig();
--
--  Before row-level trigger that displays employee number and
--  salary of an employee that is about to be added, updated,
--  or deleted in the 'emp' table.
--
CREATE OR REPLACE FUNCTION emp_sal_trig() RETURNS TRIGGER
AS $$
DECLARE
    sal_diff        NUMERIC(7,2);
BEGIN
    IF TG_OP = 'INSERT' THEN
        RAISE INFO 'Inserting employee %', NEW.empno;
        RAISE INFO '..New salary: %', NEW.sal;
        RETURN NEW;
    END IF;
    IF TG_OP = 'UPDATE' THEN
        sal_diff := NEW.sal - OLD.sal;
        RAISE INFO 'Updating employee %', OLD.empno;
        RAISE INFO '..Old salary: %', OLD.sal;
        RAISE INFO '..New salary: %', NEW.sal;
        RAISE INFO '..Raise : %', sal_diff;
        RETURN NEW;
    END IF;
    IF TG_OP = 'DELETE' THEN
        RAISE INFO 'Deleting employee %', OLD.empno;
        RAISE INFO '..Old salary: %', OLD.sal;
        RETURN OLD;
    END IF;
END;
$$ LANGUAGE 'plpgsql';
CREATE TRIGGER emp_sal_trig
    BEFORE DELETE OR INSERT OR UPDATE ON emp
    FOR EACH ROW EXECUTE PROCEDURE emp_sal_trig();
COMMIT;