O R A C L E A C A D E M Y

Transcription

1 Kenneth Mix Oracle SQL and PL/SQL notes : Passaic County Technical Institute Computer Science and Web Design National Academy Foundation Academy of Information Technology Kenneth Mix PCTI 2015 / 2016 SQL - and PL/SQL O R A C L E A C A D E M Y 1

2 Data - Data Model - ENTITY - Instance - Attribute - Relationship - Collection of facts. Identify and Organize data How data relates Conceptual Model- Idea -- blueprint Physical Model Implementation -- actual entity A named thing with known data Entities have Instances Entities have Attributes An occurrence of an Entity Describe an Entity # UNIQUE * Required Optional Association between Entities Types of Databases - Heirarchial Network Relational Business Rule - Structural Rule - Historical data - Specific Behavior of the business Types of data and their relationships Data over time Audit Trail Attributes may change UID Unique Identifier - the value that enables the user to identify an entity Simple ID - 1 Attribute Dept #code *name Artificial ID - Not real world Just to keep entities unique Social Security Number Composite ID - Made up of several parts #id #name Secondary ID - In addition to UID Allows alternative access #... # (#).. (#1). (#2). 2

3 Mutually Exclusive - Exclusive XOR If one, then NOT the other A or B, NOT BOTH One advertisement at a time. ARC EVEN T HOME Public Volatile - Mandatory - NULL - May change Required optional SORTING ASC ascending DESC descending ORDER BY Numeric Date Char NULL NULL, char, date, numeric Must be LAST clause! Can sort by ALIAS or # 3

4 Entity Relationship Diagram Capture Information NO redundant data NO derivable data ENTITY Optionality Cardinality (how many) MUST BE MAY BE ONE ONE or MORE relationship ATTRIBUTES # Unique * Required optional ERDISH EACH ENTITY A Optionality Relationship Name Cardinality ENTITY B Relationships : 1:1 Rare Common Common 1:M Rare Rare Common Common M:M Rare Common Must Resolve Common 4

5 INTERSECTION ENTITY Eliminates M:M Keep original relationships! Borrowed attribute No attribute required Hierarchical Relationship Organizational chart Family tree EMPLOYER MANAGER #emp_id #mgr_id #dir_id #mgr_id #dir_id DIRECTOR #dir_id Recursive Relationship - Between the Entity and itself EMPLOYEE #number *name *job salary bonus NOT USED OFTEN except for EMPLOYEE managed by manager of Transferability -- Cannot change! 5

6 NORMALIZATION - remove redundant data and gain efficiency 1NF 2NF 3NF eliminates repeating groups place each in a new table with a 1:M relationship. NO multi-valued attributes. eliminates dependencies on a partial key place in another table Put data in best place. eliminates dependencies on non-key fields place in another table (All non-key fields are now dependent on the key!) 2NF - TAPE MOVIE #t_num #m_id VIOLATION of 2NF! *format *title *rating *category TAPE MOVIE #t_num #m-id 2NF OK #m_id *title *format *category The m_id is borrowed *rating from MOVIE 3NF CITY #c_id *name *size *pop CITY STATE *mayor #c_id #s_id *state *name *name *flower *size *flower *pop *mayor Now in 3NF!! All attributes are now dependent on the whole key. 6

7 SDLC System Development Life Cycle Process of developing system from start to finish Relational Databases Tables can be related by a common field More than 1 table Table - Column - Primary Key - Foreign Key - Row - Field - basic storage structure with rows and columns one kind of data in a table UID for each row column that refers to a primary-key column in another table data for one table instance intersection of row and column 6 Properties : 1- entries in columns are single valued 2- entries in columns are same kind 3- each row is unique 4- column sequences is insignificant 5- row sequence is insignificant 6- each column has own names RDBMS relational data base management system Organizing data into row and columns SQL structured query language used to access data SQL Database Request processed 7

8 DML Data Manipulation Language Change the contents of a table Insert - add new row INSERT INTO table1(c1, c2, c3, c4) VALUES(123, abc,sysdate, ); Update - modify existing row UPDATE table1 SET a = b WHERE c = d if no WHERE then ALL rows updated Delete - remove existing row DELETE FROM table1 WHERE x = y; if no WHERE then ALL rows! Merge - SELECT - insert or update extract data MERGE conditionally update or insert MERGE INTO T1 USING T2 ON(C1 = V1) WHEN MATCHED THEN UPDATE SET C1 = V1 WHERE C2 = V2 WHEN NOT MATCHED THEN INSERT (C1, C2) VALUES(123, abc ); 8

9 DDL Data Definition Language define or delete db objects Create - Alter - create new table or index change structure of existing table Add / change / delect cols and constraints ALTER TABLE T1 ADD cols MODIFY cols RENAME col old to new DROP cols Constraints : DROP ENABLE DISABLE OUT OF LINE Constraint IN-LINE Constraint in column definition **USE constraint names so you can find to enable, disable or drop! Drop - Privileges required to drop NO Rollback Recycle Bin PURGE to empty DROP T1; Rename - change name of table RENAME old TO new; Truncate - deletes all rows from a table Indexes and privileges are SAVED! TRUNC T1; DROP STORAGE REUSE STORAGE 9

10 TCL Transaction Control Language All DML changes are PENDING and not available to users Close transactions Commit - KEEP IT Rollback - CANCEL IT Savepoint - interim points to rollback to LOCKING : row level released at commit! READERS Select WRITERS - Insert, Update, Delete AUTO COMMIT in PL/SQL SET AUTO COMMIT ON/OFF SHOW AUTO COMMIT DCL Data Control Language used to give or remove access rights to a database. Grant Revoke - give system privileges take away privileges ALIAS - change column name SELECT fn AS First, ln AS Last FROM table1; FIRST Last AS is optional DISTINCT returns one of each In alphabetical order Must follow SELECT DESCRIBE DESC Concatination - describes structure of a table connect strings with same data type SELECT fn x ln FROM table1; JohnxSmith 10

11 SQL RDBMS STATEMENT CLAUSE - Structured Query Language Interactive see results Embedded in a program Is NOT case sensitive SELECT and FROM required 2 or more clauses relational data base management system a set of 2 or more clauses part of an SQL statement TYPES OF SQL CALLS : Projection - Selection - Join - columns rows 2 or more tables Precedence Order of operations () 2 */+- Concatination IN( ) = comparison NOT IN( ) LIKE %_ NULL LIKE IN IS NULL BETWEEN AND IS NOT NULL BETWEEN AND NOT NOT BETWEEN AND AND OR SQL FORMAT SELECT * FROM table1; statement CLAUSE semi-colon KEYWORD 11

12 WHERE - restricts information Comparison operators : = <> < <= > >=!= ^= LOGICAL OPERATORS : AND both OR one of NOT none SELECT * FORM table1 WHERE age > 45; WHERE literal text -or- 53 numeric BETWEEN AND - a range WHERE age BETWEEN 45 AND 49; IN - membership condition A LIST WHERE type_code IN (77, 33, 56); LIKE - character pattern Wildcards % any sequence _ 1 single character WHERE ln LIKE _i% ; Mix Minkus Escape Option \ LIKE TRA\_% ; finds TRA_84 TRA_34 12

13 DUAL table - Case Functions : LOWER( s1 ) UPPER( s1 ) - INITCAP( s1 ) - one row one column To select with no table SELECT (5 * 4) FROM DUAL; convert to lower case convert to upper case convert first character (for names) SELECT fn FROM empl WHERE LOWER(fn) = John ; Character Functions : LENGTH( s1 ) INSTR( s1, c ) SUBSTR( s1, start, len) TRIM( c FROM s1 ) CONCAT( s1, s2 ) REPLACE( s1, old, new ) RPAD( s1, tot-len, s2 ) LPAD( s1, tot-len, s2 ) returns length of string returns position of x extracts specific string removes leading, trailing characters joins two strings replaces a sequence of pads right side pads left side Number Functions : ROUND(val, num) TRUNC(val, num) MOD(x, y) rounds numbers terminates a string NO rounding returns remainder Date Functions : dd 01-JAN-99 MONTHS_BETWEEN(SYSDATE, dd ) ADD_MONTHS( dd, n) NEXT_DAY( dd, Saturday ) LAST_DAY( dd ) ROUND(TO_DATE( dd ), year ) TRUNC(TO_DATE( dd ), month ) number of months between adds months to date gets the next day gets last day of month rounds to nearest year truncates to current month Date format DD-MON-YY SYSDATE returns database date and time SELECT SYSDATE FROM DUAL; SYSDATE + 1 add 1 day SYSDATE + 1 / 24 add 1 hour SYSDATE + 1/(24*60) add 1 munute 13

14 DATA TYPES : NUMBER FORMATS : DATE FORMATS : VARCHAR2(n) variable length CHAR fixed length -- 1 character NUMBER(p,s) numbers and currency DATE date and time 9 Numbers 0 leading zeroes $ currency L currency. decimal, comma xmi 56 - xpr ( ) on minus EEEE scientific notation V 99V99 10n B zero is blank YYYY 2005 YY 05 RRRR 2005 YEAR spelled out MM 06 MONTH JUNE MON JUN DD 23 DY FRI DAY FRIDAY HH hour MI minute SS second DDspth THIRD Ddspth Third ddspth third SYSDATE types INTERVAL DAY TO SECOND INTERVAL YEAR TO MONTH TIMESTAMP TIMESTAMP WITH TIMEZONE TIMESTAMP WITL LOCAL TIMEZONE EXTRACT EXTRACT(year FROM dd) 14

15 ORACLE AUTOMATIC CONVERSION: TO_CHAR(num, format ) Varchar2 Numeric TO_NUMBER() Varchar2 Date TO_DATE() Numeric Varchar2 TO_CHAR() Date Varchar2 TO_CHAR() TO_CHAR( , $9, ) $1, TO_NUMBER(s1, format ) TO_DATE(s1, format ) TO_NUMBER(1234, 9,999 ) TO_DATE(s1, date format ) use RR YYYY Current year just applied! RRRR - If Current current BEFORE AFTER current fx format explicit varchar2 to date extra blanks are ignored fxmon DD, RRRR 15

16 NULL FUNCTIONS : NVL(v1, v2) returns v2 if NULL NVL2(v1, if not NULL, if NULL) NULLIF(v1, v2) returns NULL if equal COALESCE(v1, v2, v3.) moves until NOT NULL SELECT NVL(field1, 123) FROM tab1; Returns 123 if field1 is NULL Cartesian Product - Join but NO WHERE Clause! Invalid All rows returned! 16

17 GROUP FUNCTIONS() 1 value returned per set use DSTINCT to eliminate duplicates NOT in WHERE Clause NULL is ignored (except count()) Avg() Count() Max() Min() STDDEV() SUM() VARIANCE() SELECT COUNT(last_name) FROM table1; SELECT Ln FROM T1 WHERE SALARY > (SELECT AVG(SALARY) FROM T1); GROUP BY HAVING GROUP BY - HAVING - SELECT fn, ln, AVG(sal) d FROM t1 WHERE age = 55 GROUP BY fn, ln; Control break NO alias Must List ALL columns NOT in a group() restricts rows Should have a group function() 1 SELECT 2 FROM 3 WHERE 4 GROUP BY 5 HAVING 6 ORDER BY ALL NON FUNCTION() columns must be listed here! 17

18 JOINS Oracle ANSI - Join in WHERE Clause Join in FROM Clause LEFT 1 st table RIGHT 2 nd table ORACLE ANSI Equijoin Join ON Join USING ---- NATURAL LOJ LOJ ROJ ROJ Cartesian P ---- CROSS Self TABLE NAMING RULES Start with alpha Max length = 30 Alphanumeric _ $ # 18

19 Types of joins ORACLE Equijoin Inner Simple All ROWS that match Comparison operators SELECT a.c1, b.c1 FROM T1 a, T2 b WHERE a.c1 = b.c1; Outer All rows that match PLUS rows that do not match from 1 table Place (+) on OPPOSITE side of table you want to get all data from. SELECT a.c1, b.c1 FROM T1 a, T2 b WHERE a.c1= b.c1(+) LEFT JOIN (right side)! Place (+) on OPPOSITE side of table that you want to get all rows from! Self one table Alias create different tables Recursive! SELECT a.c1, b.c1 FROM T1 a, T1 b WHERE a.c1 = b.c1; Non_Equijoin No matching columns NO Comparison operators Ranges cause joins SELECT a.c1, b.c1 FROM T1 a, T2 b WHERE a.c1 BETWEEN b.c1 AND b.c2; Cartesian Product No WHERE Clause Invalid Every combination Yearly reports 19

20 ANSI Natural Inner Joins all matching columns NO Alias NO WHERE SELECT C1, C2 FROM T1 NATURAL JOIN T2 ; Outer JOIN ON LEFT FULL RIGHT Matched rows and unmatched rows NULLS included SELECT a.c1, b.c1 FROM T1 a LEFT OUTER JOIN T2 b ON a.c1 = b.c1 WHERE Like an EQUIJOIN Joins on named columns Columns with different names (allows WHERE Clause to further filter) SELECT a.c1, b.c1 FROM T1 a JOIN T2 b ON a.c1 = b.c1 WHERE.. JOIN USING similar to NATURAL JOIN NO ALIAS REQUIRED Joins on one set of matching columns Different data types CROSS Cartesian Product! SELECT C1 FROM T1 a JOIN T2 b USING (C1) WHERE SELECT a.c1, b.c2 FROM T1 a CROSS JOIN T2 b; 20

21 INSERT Inserts new row into a table. TABLE Column Value INSERT INTO t1(c1,c2, c3, c4, c5) VALUES (123, abc,null, DEFAULT, SYSDATE); INSERT INTO table1(id, fn, ln, sa) VALUES (123, John, Smith, 123 Main ); explicit INSERT INTO table1 implicit! VALUES (123, John, Smith, 123 Main ); do not use! Use for missing data! Columns can be skipped if they accept NULL! UPDATE Updates an existing row. UPDATE t1 SET c1 = v1 WHERE c2 = v2 ; With a subquery : UPDATE t1 SET = (SELECT field1 FROM t2 WHERE id = 99); WHERE id = 88; DELETE Cannot delete row if primary key is used as foreign key in another table. DELETE FROM t1 WHERE c1 = v1; 21

22 CREATE and copy to new table : CREATE TABLE new_t1 AS (SELECT * FROM old_t2); CREATE NEW TABLE : creates a new table CREATE TABLE t1 ( var1 d_type, var2 d_type PRIMARY KEY, var3 d_type DEFAULT val1, var4 d_type DEFAULT val1 CONSTRAINT con_1 NOT NULL, var5 d_type DEFAULT val2 CONSTRAINT con_2 CHECK(var5 > 0), var6 DATE DEFALUT SYSDATE, val7 NUMBER(3), val8 NUMBER(6,2), CONSTRAINT con_4 PRIMARY KEY(var1), CONSTRAINT con_5 FOREIGN KEY(var7) REFERENCES TBL2(tbl2) ); DEFAULTS : b Null is default bb blank NULL 0.00 SYSDATE (5 * 4) abc CONSTRAINTS : rules NULL NOT NULL UNIQUE PK FOREIGN KEY ( v) REFERENCES table2(col2) referential integrity PARENT reference FK CHILD has FK Needs parent first! CHECK - rules on columns MUST be True or NULL Only for this row CHECK(id Between 5 and 10) CHECK(Fn IN( Joe, Sue )) No queries No functions 22

23 ON DELETE CASCADE - all dependent rows deleted too! Must be used OR parent rows cannot c1 d-type() CONSTRAINTS c-name REFERENCES other_t1(id) ON DELETE CASCADE CONSTRAINT c_name FOREIGN_KEY(id) REFERENCES other_t1(id) ON DELETE CASCADE ON DELETE SET NULLS - delete parent-table rows without deleting child- table rows. 23

24 DECIMAL / NUMBER DECIMAL(P,S) Precision = total length Scale = decimal positions (9,4) 9 4 = 5 There are 5 integers plus 4 integers rounding occurs if too many decimal digits PROCEDURE FUNCTION TRANSACTION TABLESPACE SYSTEM TABLESPACE - PACKAGE GREATEST - LEAST - set of tasks with no return set of tasks with a return a unit of 1 + SQL Statements where tables reside contains oracle data dictionary holds both procedures and functions returns highest (v1, v2, v3 ) returns least (v1, v2, v3 ) DECODE (oracle) (x, a1, b1, a2, b2.) if x = a1 then b1 else if x = a2 then b2 24

25 VIEW Make access eassy Stored SQL statements No table End-user security CREATE VIEW v1 AS SELECT * FROM T1; CREATE OR REPLACE VIEW v1 AS SELECT * FROM T1; create new view create or modify existing FORCE - NO FORCE - WITH CHECK OPTION WITH READ ONLY - DROP - SIMPLE - COMPLEX - even without a table requires a table only accessible rows NO DML remove view 1 table DML 1 + tables NO DML IN LINE VIEW A query in the FROM clause UPDATE ( SELECT C1 FROM T1 WHERE C1 = V1) Set C1 = V2; Top-N gets specific number of rows SELECT * FROM ( SELECT C1, C2 FROM T1 ORDER BY C1 DESC) WHERE ROWNUM <= 5; 25

26 SUBQUERIES a select embedded in a select ( ) in parentheses can be FROM, WHERE, HAVING SINGLE ROW - 1 row returned Comparison operator =!= < <= > >= LIKE SELECT LAST_NAME, FIRST_NAME, SALARY FROM STAFF WHERE SALARY < (SELECT MAX(SALARY) FROM STAFF); SELECT a.c1, a.c2 FROM T1 a WHERE a.c1 IN (SELECT b.c1 FROM T2 b WHERE b.c2 IN(1,3,5); SELECT LAST_NAME, MIN(SALARY) FROM STAFF GROUP BY DEPARTMENT_ID HAVING MIN(SALARY) > (SELECT MIN(SALARY) FROM STAFF WHERE DEPARTMENT_ID = 50); MULTI-ROW - many rows returned In outer query WHERE IN - Comparison operators : ANY - ALL - within the list returned in at least 1 of them returned in all of them returned EXISTS - NOT EXISTS something is returned nothing is returned 26

27 INDEX Eliminates full table scans Speeds up retrieval Takes up space Large tables with small results Maintained by Oracle DBMS CREATE INDEX I1 ON T1(c1, c2); Columns can be expressions, functions Simple 1 column Complex 1+ columns DROP INDEX I1; ALTER INDEX I1 DISABLE ENABLE RENAME to REBUILD SYNONYM To reference other data Simplify access CREATE PUBLIC SYNONYM syn-name FOR Object; DROP PUBLIC SYNONYM syn-name; SEQUENCE generate unique numbers for Primary Key Gaps may appear CREATE SEQUENCE seq-name START WITH x INCREMENT BY x MAXVALUE x MINVALUE x CYCLE NOCYCLE CACHE NOCACHE; ALTER SEQUENCE seq-name; DROP SEQUENCE seq-nqme; INSERT INTO t1(c1, c2) VALUES(seq_name.NEXTVAL, val2.currval); CURRVAL NEXTVAL SELECT seq1.currval FROM DUAL; seq1.nextval 27

28 Data type Default - Explicit - Implicit - Format Hone Iteration Read consistency fm Privileges: classification of a variable automatically assigned value until override clearly expressed not direct, implied arrangement of data sharpen repeating a consistent view of the data format model - remove blanks or leading zeroes SYSTEM privileges - non-object related Create, session OBJECT privileges DML COMMENTS - /*..*/

29 SECURITY Add / change / delete users: CREATE USER name1 IDENTIFIED BY pass1; GRANT CREATE SESSION TO name1; ALTER USER name1 IDENTIFIED BY pass1; DROP USER name1; Add database: CREATE ALTER. DROP. RENAME TRUNCATE. INSEX SYNONYM SEQUENCE TABLE VIEW. CREATE DATABASE IF NOT EXISTS name1; DROP DATABASE IF EXISTS name1; PRIVILEGES SYSTEM PRIVILEGES CREATE SESSION CREATE TABLE CREATE USER CREATE ALTER VIEW OBJECT PRIVILEGES DMLs ALTER EXECUTE INDEX REFERENCES GRANT ALL PRIVILEGES ON object TO USER/PUBLIC WITH GRANT OPTION; REVOKE ALL PROVILEGES ON object FROM USER/PUBLIC; GRANT ALL/SELECT/UPDATE/DELETE ON T1 TO newuser WITH GRANT OPTION; GRANT EXECUTE ON proc1 TO newuser REVOKE ALL/INSERT/UPDATE/DELETE ON T1 FRM newuser; 29

30 ROLE groups of privileges Makes control casier CREATE ROLE r1 GRANT CONNECT TO r1 GRANT EXECUTE ANY procedure TO r1 GRANT SELECT ON T1 to r1; PL / SQL SECTION PL/SQL - made up of BLOCKS Anonymous BLOCKS - Not connected to db cursors no name variables Declare sub-programs Begin procedures exceptions run-time errors end; ends block DECLARE v1 number := 123; BEGIN DBMS_OUTPUT.PUT_LINE( v1 ); EXCEPTION WHEN --some error in BEGIN -- THEN DBMS_OUTPUT.PUT_LINE( error ); END; 30

31 Named BLOCKS - stored in db sub-programs functions procedures packages header declaration executable exception Overloading - same procedure name with different arguments. OPERATORS - := assignment V1 := 123; V2 := v1 v2; V3 := upper(s1); => association (v1 => 25); named notation DESCRIBE - returns argument list VARIABLES - must be declared BEFORE local sub -programs Constant NOT NULL := val -or- default val Name data type ; Max len = 30 Start with alpha Character/number set $ # No spaces No reserved words 31

32 PL/SQL PARAMETERS - a value passed to a sub-program. Formal parameters defined in a list before IS/AS name mode data_type positional named - mixed - in order via name V1 => 5 [any order] combo modes - IN - default values / read only OUT - NO default values IN OUT - NO default values Actual parameters values passed to sub-program Formal parameters => actual parameters variables Host variable holds values passed back by the OUT mode. Must have : used to separate from local Local Parameters - VARIABLE xx varchar2(50); EXECUTE p1 (:xx, :yy); declared after IS keyword and before begin keyword. If nested procedure, variables must be declared before nested procedure declared. SQL *PLUS EXECUTE - PRINT runs existing sub-program DBMS_OUTPUT.PUT_LINE( xyz v1); DROP - drops sub-programs, procedures or functions Cannot be part of a package Cannot be within a block No rollback allowed DROP procedure P1; 32

33 Sub Programs - performance security maintanance clarity Stored in db 1 statement is required Compiled to p-code Must be declared AFTER local variables Procedures - Perform an action May return 1 or more values through mode Called through an SQL statement Inherit privileges of owner Functions - Must return 1 value through RETURN Called as part of an SQL expression Can be used as a variable NO host variables NO group functions or DECODE Formal parameters create or replace procedure p1(v1 IN varchar2) is begin block exception DECLARATION SECTION end p1; LOCAL VARIABLES create or replace function f1(v1 IN varchar2) RETURN varchar2 is v2 varchar2(50); begin RETURN V2; exception end p1; 33

34 create new procedure function trigger package or replace copy over privileges remain the same SAMPLE code with SQL- number) create or replace procedure p1 (id IN number, fn OUT varchar2, salary OUT is begin SELECT first_name, emp_salary INTO fn, salary FROM EMPL WHERE empl_id = id; end p1; execute p1(1, :v_fn, :v_sal); : references the variable in the execute command. %TYPE DEFAULT x gets data type from column or variable t1.c1%type mode must be IN create or replace procedure p1 (fn t1.fn1%type default John ) is (fn T1.C1%TYEP DEFAULT John ) 34

35 Invoking procedures - from stand-alone SQL*PLUS execute p1; uses default values execute p1(1); only first value passed execute p1(id => 33); passes id = 33 execute p1( :var1, :var2 + 25); passes local : references local variable from Anonymous block named block sub-program - BEGIN P1(x); END; Invoking functions - SELECT f1(1) FROM T1; SELECT fn FROM T1 WHERE ln = f1(1); EXECUTE :ln := f1(1); From SQL clauses - SELECT UPDATE DELETE INSERT WHERE GROUP BY HAVING ORDER BY SET WHERE WHERE VALUES 35

36 EXCEPTIONS - unpredictable situations Implicit Explicit Oracle PreDefined Oracle Non-PreDefined User-Defined Oracle PreDefined Error - Just the exception Oracel Non-PreDefined Error - NO_DATA_FOUND TOO_MANY_ROWS INVALID_CURSOR ZERO_DIVIDE DUP_VAL_ON_INDEX DECLARE E1 EXCEPTION; PRAGMA EXCEPTION_INIT(E1, ); EXCEPTION WHEN E1 THEN ---- USER-DEFINED Error - Raised DECLARE E1 EXCEPTION; BEGIN if SQL%NOTFOUND THEN RAISE E1; EXCEPTION WHEN E1 THEN or -- RAISE_APPLICATION_ERROR(#, message, TRUE); custom keep RAISE - Invokes user-defined error Execution ends Control passed to exception handling section Declared in declaration section Raised in executable section Handled in exception handling section 36

37 Parts of an exception : Name Type - Exception code Error code description area of error ORA or- PLS numeric code ORA info about error SQLERRM message -- both must be variables SQLCODE code PRAGMA EXCEPTION_INIT - non-predefined error (E1, ); RAISE_APPLICATION_ERROR - user-defined error (#, message, keep) Retrieve error code SQLERRM message SQLCODE - number 0 no exception 1 user defined error no data found (-) Oracle Server Error V_ERROR_CODE NUMBER; V_ERROR_CODE := SQLCODE;

38 DATA TYPES scalar 1 value char DATE Number Boolean %TYPE Composite multiple table Record Nested table Varray LOB large objects and IMAGES Database column CLOB book BLOB pictures BFILE binary / movie NCLOB foreign font REFERENCE OBJECT pointer a schema with a name Character data type : Char 1 to Default 1 Varchar2( ) Long Long RAW no default > 2 billion binary RAW unknown to PL/SQL Number data type : Number (p, s) BINARY_INTEGER PLS_INTEGER BINARY_FLOAT BINARY_DOUBLE precision, scale +- 2 billion +- 2 billion fast floating point 5 bytes floating point 9 bytes 38

39 DATE data type : SECONDS DATE TIME OF DAY IN TIMESTAMP y, m, d, h, m, s + local & UTC database TIMESTAMP WITH TIME ZONE difference TIMESTAMP WITH LOCAL TIME ZONE inserted into INTERVAL YEAR TO MONTH INTERVAL DAY TO SECOND intervals intervals BOOLEAN DATA TYPE : TRUE FALSE NULL DATA TYPE CONVERSION IMPLICIT EXPLICIT dynamically in a statement SLOW You lose control Environment specific through built in functions TO_CHAR( ) TO_NUMBER ( ) TO_DATE( ) TO_CLOB( ) CHARTOROWID( ) RAWTOHEX( ) ++ MORE! 39

40 PRIVILEGE - right to perform an action Granted to : a schema user role public user group System privilege - right to perform an action in all schemas Granted to a schema ANY - PUBLIC - in entire database in entire database and into future WITH ADMIN OPTION grantee can pass privileges to other schemas GRANT CREATE TABLE TO STEVE can create in their own schema GRANT CREATE ANY TABLE TO STEVE can create in all schemas GRANT EXECUTE ANY PROCEDURE TO STEVE GRANT CREATE ANY PROCEDURE TO STEVE CREATE ANY PROCEDURE TO STEVE sub programs In any schema NO DROP NO ALTER NO -- OR REPLACE Object privilege - schema right to perform an action on a specific object in another MUST include object name ON named object GRANT SELECT ON T1 TO USER_B; Issued by USER_A WITH GRANT OPTION allow to pass object privileges to other schemas GRANT EXECUTE ON F1 TO JOE GRANT EXECUTE ON PK1 TO JOE 40

41 Types of privileges - CREATE ALTER DROP SELECT EXECUTE procedures, functions, packages.. GRANT priv TYPE ANY/ON object TYPE TO USER GRANT - REVOKE - used to assign privilege used to remove privilege Revoke object privilege - Revoke system privilege - cascading NOT cascading ANY - IN - INVOKER - DEFINER - for system privileges for object privileges Person who executes Must have execute privilege the owner who creates an object 41

42 Data Dictionary VIEWS / columns : USER-PROCEDURES names of all units Object Procedure name the name USER_SOURCE names or all uinits that invoke a procedure Text Name USER_OBJECTS - source code information about program units Object type Created - LAST_DDL_TIME - Status procedure, function. date when compiled VALID / INVALID USER_ERRORS SHOW_ERRORS Sample privileges : ALTER ANY PROCEDURE AUTHID CURRENT_USER - AUTHID DEFINER - to manually recompile to use invoker rights default Procedure is invoked with owner rights

43 Packages - groups related procedures Cannot be invoked Entire package loaded into memory Dot notation EXECUTE S1. PKG1. P1(x); PARTS not stored together schema INTERFACE only Executable code package specification package body required public Must be created FIRST name public declarations public sub-programs optoinal private name private declarations private sub-programs DOT NOTATION - for outside access only public constructs can be referenced from outside PK1.P1(x); PRAGMA compiler directives How to view a package status SELECT OBJECT_TYPE FROM OBJECT_VIEWS WHERE OBJECT_NAME = x ; BODILESS PACKAGE no package body Used to initialize global variables PACKAGE CONSTRUCTS - procedures functions cursors variables exceptions types 43

44 Create a package CREATE OR REPLACE PACKAGE pkg1 IS Variables / cursors Sub-programs END pkg1; Package variable - NULL if not assigned a value CREATE OR REPLACE PACKAGE pkg1 AS V1 number; END pkg1; DROP package DROP PACKAGE pkg1; DROP PACKAGE BODY p1; body dropped only DESCRIBE (package) Returns complete structure Argument list Lists package constructs Lists column information Function return data-type DESCRIBE PK1; PRAGMA Purity Levels WNDS writes no database state RNDS reads no database state WNPS writes no package state RNPS reads no package state Package purity - Forward declaration Parts of Package Body amount free from side effects declare subprogram specification BEFORE the body specification Header Declaration Execution 44

45 BASIC LOOP NO conditions Runs at least once 1 EXIT required LOOP S1; EXIT WHEN x = y; END LOOP; WHILE LOOP runs while test is true WHILE x < 3 LOOP S1; S2; X = x + 1; END LOOP; FOR LOOP Specific number of iterations Automatic increment FOR C IN low.. high LOOP S1; S2; END LOOP; NESTED LOOP <<outer>> LOOP <<inner>> LOOP EXIT outer WHEN x = y; EXIT WHEN a = b; END LOOP; END LOOP;

46 CASE STATEMENT evaluates a condition END CASE; CASE v1 WHEN 5 THEN s1; WHEN 10 THEN s2; ELSE s3; END CASE; CASE EXPRESSION V1:= returns a value to a variable No semi colons until END; Case V2 WHEN 5 THEN s1 WHEN 10 THEN s2 ELSE v3 END; CASE LOGIC TABLE AND T F N OR T F N T t f N T t t t F f f f F t f N N N f N N t N N 46

47 CURSORS IMPLICIT Defined by Oracle One row EXPLICIT - Defined by programmer Many rows returned DECLARE CURSOR CS1 IS SELECT fn, ln FROM T1 WHERE id = x; V1 varchar2(); V2 varchar2(); BEGIN OPEN CS1; LOOP FETCH CS1 INTO v1, v2; EXIT WHEN CS1%NOTFOUND; DBMS_OUTPUT.PUT_LINE(v1, v2); END LOOP; CLOSE cs1; END; Active Set - Context Area - OPEN cursor - FETCH - rows returned by a query the location where rows are stored allocates memory Executes SELECT SETS Pointer to top retrieves rows from cursor CURSOR ATTRIBUTES : %NOTFOUND - %ISOPEN %FOUND %ROWCOUNT Test for end of cursor True if cursor opened True if most recent fetch is found Total rows fetched SO FAR. If NOT CS1%OPEN THEN OPEN CS1; END IF; EXIT WHEN CS1%ROWCOUNT > 5; 47

48 CURSOR %ROWTYPE Takes the Record structure SAME FIELDS AS IN THE SELECT. DECLARE CURSOR CS1 IS SELECT * FROM T1; ROW1 CS1%ROWTYPE; BEGIN OPEN CS1 LOOP FETCH CS1 INTO ROW1; EXIT WHEN CS1%NOTFOUND; DBMS_OUTPUT.PUT_LINE(ROW1.C1); END LOOP; CLOSE CS1; END; CURSOR PARAMETER A variable used in a cursor declaration Multiple opens and closes (with different values) DECLARE CURSOR CS1 (V1 number) IS SELECT fn, ln FROM T1 WHERE id = V1; ROW1 CS1%ROWTYPE; BEGIN OPEN CS1(5); LOOP FETCH CS1 INTO ROW1; EXIT WHEN CS1%NOTFOUND; DBMS_OUTPUT.PUT_LINE(c1, c2); END LOOP; CLOSE CS1; END; 48

49 CURSOR FOR LOOP declare, open, fetch, %notfound, close No variables for fetched data Can be in a sub-query FOR i IN CS1 LOOP S1; S2; EXIT WHEN CS1%ROWCOUNT > 5; BDMS_OUTPUT.PUT_LINE( i.c1 ) END LOOP; optional dot.notation CURSOR IN SUBQUERY FOR i IN (SELECT C1, C2 FROM T1 WHERE C3 > 0) LOOP CURSOR UPDATE DECLARE CURSOR CS1 IS SELECT C1, C2 FROM T1 FOR UPDATE OF C3 NOWAIT BEGIN FOR ROW1 IN CS! LOOP UPDATE T1 SET C3 = x; WHERE CURRENT OF CS1; END LOOP; END; WAIT n - NOWAIT - wait a number of seconds immediate error WHERE CURRENT OF CS1 - Most recent fetched row Used with SET C1 = joe ; UPDATE DELETE FOR UPDATE OF C1- only column locked FOR UPDATE entire record is locked 49

50 ORACLE SUPPLIED PACKAGES - DBMS_SQL For DDL statements For dynamic SQL PARSE - EXECUTE - FETCH_ROWS - OPEN_CURSOR - verify syntax and privileges # of rows processed # fetched rows open cursor and allocate memory SET SERVEROUTPUT ON - for SQL*PLUS DBMS_OUTPUT - PUT_LINE - PUT - package to display messages during session procedure to display put text to buffer for future use DBMS_OUTPUT.PUT_LINE(TO_CHAR(SQL%ROWCOUNT)); EXECUTE IMMEDIATE - Fast and Easy Single row queries Dynamic SQL execution Supports user_defined types NOT for client-side EXECUTE IMMEDIATE DELETE T1; Order of steps : 1 - Parse - verify syntax and privileges 2 - Bind - initialize variables 3 - Execute - SQL processed and rows returned 4 - Fetch - specific condition rows returned DBMS_PIPE - send and receive messages across a user session Number Varchar2 RAW ROWID DBMS_DDL issues certain types of DDL commands 50

51 ALTER_COMPILE - a procedure used to issue alter/compile statement. ALTER PROCEDURE JOE.P1 COMPILE; BEGIN DBMS_DDL.ALTER_COMPILE( PROCEDURE, Joe, P1 ); END; DBMS_JOB package used to run jobs at user-defined times. SUBMIT - Submits desired code JOB : - name of job WHAT : - specifies the PL/SQL code to be run NEXT_DATE : - the next date job will run INTERVAL : - time between jobs NO_PARSE : - when parsing is to occur BOOLEAN True or False UTL_FILE - package to read and write to operating system FOPEN : - open for read or write PUT_LINE - writes the strings from buffer to open file PUTF : - %s substitute value \n new line FCLOSE closes file UTL_TCP - read or write from remote host OPEN_CONNECTION CLOSE_CONNECTION - UTL_HTTP - allows PL/SQL to act as a browser 51

52 Table of records - 1 SELECT statement Stores all rows and columns Composite data type TYPE T_ROW IS RECORD PRAGMA RESTRICT_REFERENCES - specifies the purity of a function What is can and cannot do PRAGMA RESTRICT_REFERENCES(F1, WNDS); Side Effects - package specification changes to the database or variables in FORWARD REFERENCING - FORWARD DECLARATION - in another NOT is SQL Sub programs MUST be declared before use declare a sub program before referencing it sub program. Just a header / arguments is required. ONT-TIME ONLY PROCEDURE - defined in body Executed when package is first invoked PERSISTENT STATE OF PACKAGED VARIABLE - only for each changes are made Session 52

53 TRIGGER - runs when something happens NO arguments DDL (INSERT, UPDATE, DELETE) DML (CREATE, ALTER, DROP) NO TCL (commit, savepoint, rollback) If exception, then rollback occurs EVENTS THAT FIRE A TRIGGER - Data Event - FOR EACH ROW DDL DML STATEMENT LOGON System Event - FOR EACH At schema level ON LOGOFF / ON Always fires TYPES OF TRIGGERS - ROW TRIGGER - FOR EACH ROW :old :new capture before and after Logs into audit table STATEMENT STATEMENT TRIGGER - FOR EACH TRIGGER TIMING - Remove a trigger - BEFORE rows not locked AFTER rows locked and constraint checks done DROP TRIGGER TG1 Alter trigger - ALTER TRIGGER TG1 ENABLE DISABLE ALTER TABLE T1 DISABLE ALL TRIGGERS TRIGGER FIRING SEQUENCE - 1. Before each statement 2. Before each row 3. UPDATE 4. After each row 5. After each statement 53

54 INSTEAD OF - Fires on a VIEW A row trigger Replaces the trigger statement Trigger manipulation test UPDATING DELETING INSERTING SAMPLE Update Row TRIGGER code timing / event CREATE OR REPLACE TRIGGER TG1 BEFORE UPDATE OF salary ON T1 FOR EACH ROW WHEN A > B BEGIN IF UPDATING ( salary ) THEN :new.salary := 2000; :new.name := USER; END IF END; MUTATING TABLE - when a trigger reads and writes at the same time. 54

55 DEPENDENT OBJECT - REFERENCED OBJECT - INDIRECT REFERENCE - an object that references another object CALLING CALLED through intermediate construct LOCAL DEPENDENT OBJECT - in same database Oracle attempts to recompile REMOTE DEPENDENCIES - rely on object in another database USER_DEPENDENCIES VIEW on direct dependencies To Display Indirect/direct Dependencies - Utldtree.sql dependencies IDEPTREE - DEPTREE - DEPTREE_FILL - DEPTREE_TEMPTAB - indented, indirect chart populate table holds data EXECUTE DEPTREE(o-type, owner, name); BEGIN DEPTREE_FILL(o-type, owner, name); END; DEPENDENCY MODES - TIMESTAMP SIGNITURE To recompile - ALTER PROCEDURE P1 COMPILE; ALTER PACKAGE PK1 COMPILE BODY SPECIFICATION PACKAGE 55

56 LOB Large Objects Can store anything anywhere Can be many columns 4gb 9i 128TB 10g CLOB BLOB BFILE NCLOB TEXT HTML PL/SQL PICTURES MP3.exe Binary Files Can be outside database MOVIES / AUDIO NO DVD NO privileges National character set LOB directory - LOB VALUE - LOB Locator - Out-Of-Line - pointer to BFILE LOB data pointer to LOB file where file is stored To add column ALTER TABLE T1 ADD (file CLOB ); BLOB EMPTY_CLOB - DBMS_LOB - Initialize pointer & memory Done BEFORE populating package to manage LOB to access BFILE To load the values DBMS_LOB.FILEOPEN - DBMS_LOB.FILECLOSE to open BFILE to close BFILE 56

57 Convert to LOB ALTER TABLE T1 MODIFY (file CLOB ); BLOB NCLOB LONG to LOB LONG to CLOB LONG to NCLOB LONG RAW to BLOB Temporary LOB - used to create temporary CLOB, BLOB, NCLOB Faster NO Rollback Change formats (GIF to JPEG) NO EMPTY_BLOB or EMPTY_CLOB DBMS_LOB.CREATETEMPORARY create temp LOB. BFILENAME - used initialize a BFILE column 57