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BACS 485—Database Management
Advanced SQL
Overview Advanced DDL, DML, and DCL Commands
BACS 485—Database Management
Lecture Objectives Review basic DDL, DML, and DCL SQL
commands used in Oracle Learn advanced SQL commands useful
for DBA’s and database programmers
BACS 485—Database Management
Oracle SQL DDL
Basic Object Manipulation Set Create Table (Alter, Drop) Create View (Alter, Drop) Create Index (Alter, Drop) Create Sequence (Alter, Drop)
BACS 485—Database Management
Create Table CommandsCREATE TABLE name (col-name type [(size)][CONSTRAINT],...);
CONSTRAINT name {PRIMARY KEY | UNIQUE | REFERENCES foreign_table
[(foreignfield)] }
Basic Create Table:
CREATE TABLE STUDENT(STUID CHAR (5) PRIMARY KEY, SSN CHAR (9), LNAME VARCHAR2 (25), FNAME VARCHAR2 (15), MAJOR VARCHAR2 (7), CREDITS NUMBER (1));
BACS 485—Database Management
Create Table CommandsCREATE TABLE scott.emp
(empno NUMBER CONSTRAINT pk_emp PRIMARY KEY, ename VARCHAR2(10) CONSTRAINT nn_ename NOT NULL
CONSTRAINT upper_ename CHECK (ename = UPPER(ename)),job VARCHAR2(9),mgr NUMBER CONSTRAINT fk_mgr REFERENCES scott.emp(empno) on delete cascade,hiredate DATE DEFAULT SYSDATE,sal NUMBER(10,2) CONSTRAINT ck_sal CHECK (sal > 500),comm NUMBER(9,0) DEFAULT NULL,deptno NUMBER(2) CONSTRAINT nn_deptno NOT NULL CONSTRAINT fk_deptno REFERENCES scott.dept(deptno));
BACS 485—Database Management
Alter Table CommandsALTER TABLE emp
ADD (CONSTRAINT sal_com_cc CHECK (sal + comm <= 5000))DISABLE CONSTRAINT sal_com_cc;
ALTER TABLE EMP DROP (SSN) CASCADE CONSTRAINTS;
ALTER TABLE dept ADD CONSTRAINT manager_fk FOREIGN KEY (manager) REFERENCES emp (mgr);
ALTER TABLE empADD (thriftplan NUMBER(7,2),
loancode CHAR(1) NOT NULL);
BACS 485—Database Management
Create View CommandsCREATE VIEW dept20 AS
SELECT ename, sal*12 annual_salaryFROM empWHERE deptno = 20;
CREATE VIEW clerk (id_number, person, department, position) ASSELECT empno, ename, deptno, job
FROM empWHERE job = ’CLERK’WITH READ ONLY;
ALTER VIEW customer_view COMPILE;
DROP VIEW dept20;
BACS 485—Database Management
Index CommandsCREATE INDEX emp_idx ON scott.emp (ename);
CREATE INDEX emp_i ON emp (UPPER(ename));
ALTER INDEX emp_ix REBUILD REVERSE;
DROP INDEX monolith;
BACS 485—Database Management
Sequence CommandCREATE SEQUENCE seq1 INCREMENT BY 10;
CREATE SEQUENCE acct_seqINCREMENT BY 10 START WITH 100 NOMAXVALUENOCYCLE CACHE 10;
ALTER SEQUENCE seq1MAXVALUE 1500;
DROP SEQUENCE elly.seq1;
BACS 485—Database Management
Oracle SQL DML
Select Insert Update Delete
BACS 485—Database Management
Select CommandsSELECT {field-list | * | DISTINCT field}
FROM table-listWHERE expressionGROUP BY group-fields
HAVING group-expressionORDER BY field-list;
Basic Select Example:
Select * From EmpWhere Salary > 45000 and Status = “Full Time”
Order By SSN;
BACS 485—Database Management
More Complex SelectsSELECT deptno, MIN(sal), MAX (sal)
FROM empWHERE job = 'CLERK'GROUP BY deptno
HAVING MIN(sal) < 1000;
Would print:
DEPTNO MIN(SAL) MAX(SAL)---------- ---------- ----------20 800 110030 950 950
BACS 485—Database Management
SQL Aggregate Functions AVG Average of non-null values
NUMBER COU[NT] Count of non-null values
All types MIN[IMUM] Minimum value
NUMBER, CHAR, NCHAR, VARCHAR2 (VARCHAR), NVARCHAR2 (NCHAR VARYING)
MAX[IMUM] Maximum value NUMBER, CHAR, NCHAR, VARCHAR2 (VARCHAR), NVARCHAR2 (NCHAR
VARYING) NUM[BER] Count of rows
All types SUM Sum of non-null values
NUMBER STD Standard deviation of non-null values
NUMBER VAR[IANCE] Variance of non-null values
NUMBER
BACS 485—Database Management
Other Select Operators Logical Operators
And Or Not
Comparison Operator =,<>,<,<=,>,>= IS NULL BETWEEN…AND IN LIKE
BACS 485—Database Management
Multi-Table Joins Data from 2 or more tables can be
combined into a single select by several methods. Use ‘where’ clause to combine all
data Use Suq-query
Equi-join Non-Equi-join Outer Join Self-Join
BACS 485—Database Management
Select Sub-Query Sub-queries allow a component of a simple select to be an
embedded select statement.
SELECT Ename, sal FROM emp WHERE deptno = (SELECT deptno FROM dept WHERE dname = 'ACCOUNTING');
BACS 485—Database Management
Sub-query operators The following operators can be
used to select one or more tuples in a sub-query. Single row queries
=, <>, >,>=,<,<= Multiple row queries
IN – equal to any values in a list ALL – compare to all values in list ANY – compare to each value in list
BACS 485—Database Management
Single Row Sub-QuerySELECT deptno, UPPER(ename), sal
FROM emp xWHERE sal >
(SELECT AVG(sal)FROM empWHERE x.deptno = deptno)
ORDER BY deptno;
BACS 485—Database Management
Multiple Row Query Operators >ALL means more than the maximum value in list <ALL means less than the minimum value in list >ANY means less than the maximum value in list <ANY means more than the minimum value in list
Note, from the diagram below, it is obvious that overlap is possible. The key to understanding is to remember that these operators are used to determine how a specific value relates to a list. Different operators would produce different relations.
10 20
>Any
<Any > All
< All530
14
18
BACS 485—Database Management
Multiple Row Sub-queriesSELECT SSN, Lname FROM student WHERE FacID IN
(SELECT FacID FROM faculty WHERE deptID = 1);
SELECT empno, lname, fname, salaryFROM employeeWHERE salary >ANY
(SELECT salary FROM employee WHERE posID = 2)AND posID <> 2;
SELECT empno, lname, fname, salaryFROM employeeWHERE salary <ALL
(SELECT AVG(salary) FROM employee GROUP BY deptID);
BACS 485—Database Management
Character Functions Upper (col) – changes all to uppercase
Lower (col) – changes all to lowercase
Initcap (col) – first character of each word uppercase
Concat (col1,col2) – joins 1st value to 2nd value
Substr (col, x, y) – returns substring starting at ‘x’ for ‘y’ characters
Instr (col, c) – returns position of 1st ‘c’ character
Trim(‘c’ FROM col) – removes ‘c’ leading and trailing characters
Length (col) – returns length
Lpad(col,n,str) – pads value with ‘str’ to the left to total width of ‘n’
BACS 485—Database Management
Date Manipulation Months_Between (date1,date2) – Number months
between 2 dates Add_Months (date, m) – Add calendar months to a date
Next_Day (date, ‘day’) – Find next day after a date
Last_Day (date) – Find last day of the month
Round (date) – Round to nearest day, month, or year
Trunc (date) – Truncate date to nearest day, month, or year
Date + number – Add days to a date
Date – number – Subtract days from a date
Date + number/24 – Add hours to a date
Date1 – Date 2 – Find number of days between 2 dates
BACS 485—Database Management
Math Manipulation Round (col, n) – Round column to n decimal
places
Trunc (col, n) – Truncate the column to n decimal places
Power (n,p) – returns np
Abs (n) – Absolute value of n
Mod (x,y) – integer remainder of x/y
+, -, *, / - perform basic mathematical operations
BACS 485—Database Management
Complex Select Sub-QueriesSELECT a.deptno "Department",
a.num_emp/b.total_count "%Employees", a.sal_sum/b.total_sal "%Salary"FROM (SELECT deptno, COUNT(*) num_emp, SUM(SAL) sal_sum
FROM scott.empGROUP BY deptno) a,
(SELECT COUNT(*) total_count, SUM(sal) total_salFROM scott.emp) b ;
BACS 485—Database Management
Complex Select Sub-QueriesSELECT Tablespace_Name, Max_Blocks, Block_Count, Total_Blocks_Free, ((Total_Blocks_Free/Total_Allocated_Blocks)*100) AS Pct_Free
FROM (SELECT Tablespace_Name, SUM(Blocks) Total_Allocated_Blocks
FROM DBA_DATA_FILES GROUP BY Tablespace_Name), (SELECT Tablespace_Name Free_Space, MAX(Blocks) AS Max_Blocks,
COUNT(Blocks) AS Count_Blocks, SUM(Blocks) AS Total_Free_Blocks FROM DBA_FREE_SPACE GROUP BY Tablespace_Name)WHERE Tablespace_Name = Free_Space;
BACS 485—Database Management
Complex Select Sub-QueriesFind the top 2 salaries in each department:
SELECT m.ename, m.sal, m.deptnoFROM emp mWHERE m.sal >=
(SELECT DISTINCT o.sal FROM emp 0 WHERE (o.sal, 2) IN (SELECT i.sal, ROWNUM
FROM (SELECT DSTINCT i2.sal r_sal,i2.deptno, i2.sal, i2.ROWIDFROM emp i2) IWHERE I.deptno = m.deptno))
ORDER BY deptno, sal DESC;
ENAME SAL DEPTNO----- --- -----KING 5000 10CLARK 2450 10SCOTT 3000 20FORD 3000 20BLAKE 2850 30
BACS 485—Database Management
Complex Select Sub-QueriesFind top 3 travel agents based on tickets sold:
SELECT id, ticket_price, agent_rankFROM (SELECT agent_id AS id,
SUM(ticket_price) AS ticket_price,RANK() OVER (ORDER BY SUM (ticket_price) DESC) AS agent_rank
FROM invoice GROUP BY agent_id)
WHERE agent_rank < 4;
ID Ticket_Price Agent_rank-- ------------ ----------1234 8141 15675 6708 24434 5140 3
BACS 485—Database Management
Select Self-JoinSELECT e1.ename || ‘ works for ’ || e2.ename
"Employees and their Managers"FROM emp e1, emp e2 WHERE e1.mgr = e2.empno;
Would Print:
Employees and their Managers-------------------------------BLAKE works for KINGCLARK works for KINGJONES works for KINGFORD works for JONESSMITH works for FORDALLEN works for BLAKEWARD works for BLAKE
…
BACS 485—Database Management
Select Outer JoinSELECT ename, job, dept.deptno, dname
FROM emp, deptWHERE emp.deptno (+) = dept.deptno;
SELECT custname, TO_CHAR(orderdate, ’MON-DD-YYYY’) "ORDERDATE", partno, quantity
FROM customers, orders, lineitemsWHERE customers.custno = orders.custno (+)
AND orders.orderno = lineitems.orderno (+);
BACS 485—Database Management
Decode StatementSELECT ename, deptno,
DECODE (deptno, 10, ‘ACCOUNTING’,20, ‘RESEARCH’,30, ‘SALES’,‘NOT INDICATED’)
FROM emp;
ENAME DEPTNO DECODE(DEPTNO----- ------ -------------TURNER 30 SALESALLEN 20 RESEARCHJONES 10 ACCOUNTINGWARD 20 RESEARCH
BACS 485—Database Management
Insert CommandsINSERT INTO deptVALUES (50, ’PRODUCTION’, ’SAN FRANCISCO’);
INSERT INTO emp (empno, ename, job, sal, comm, deptno)VALUES (7890, ’JINKS’, ’CLERK’, 1.2E3, NULL, 40);
INSERT INTO (SELECT ename, deptno FROM emp WHERE deptno < 10)VALUES (’Taylor’, 20);
INSERT INTO bonusSELECT ename, job, sal, comm
FROM empWHERE comm > 0.25 * sal
OR job IN (’PRESIDENT’, ’MANAGER’);
INSERT INTO emp VALUES (empseq.nextval, ’LEWIS’, ’CLERK’,7902, SYSDATE, 1200, NULL, 20);
BACS 485—Database Management
Update CommandsUPDATE emp
SET comm = NULL WHERE job = ’TRAINEE’;
UPDATE empSET job = ’MANAGER’, sal = sal + 1000, deptno = 20
WHERE ename = ’JONES’;
UPDATE empSET sal = sal * 1.1 WHERE empno NOT IN
(SELECT empno FROM bonus);
BACS 485—Database Management
Complex Update CommandUPDATE emp a
SET deptno = (SELECT deptno
FROM dept WHERE loc = ’BOSTON’),(sal, comm) = (SELECT 1.1*AVG(sal), 1.5*AVG(comm)
FROM emp bWHERE a.deptno = b.deptno)
WHERE deptno IN(SELECT deptno FROM dept WHERE loc = ’DALLAS’ OR loc = ’DETROIT’);
BACS 485—Database Management
Delete CommandDELETE FROM temp_assign;
DELETE FROM empWHERE JOB = ’SALESMAN’
AND COMM < 100;
DELETE FROM (select * from emp)WHERE JOB = ’SALESMAN’
AND COMM < 100;
BACS 485—Database Management
Oracle SQL DCL
Commit Rollback
BACS 485—Database Management
CommitINSERT INTO dept VALUES (50, ’MARKETING’, ’TAMPA’);COMMIT;
COMMITCOMMENT ’In-doubt transaction Code 36, Call x1122’;
BACS 485—Database Management
RollbackROLLBACK;
ROLLBACK TO SAVEPOINT sp5;