Teach Yourself PL/SQL in 21 Days- P16

monitoring locks, 449 rows, 445

tables, 443-444 exclusive mode, 444 row exclusive mode, 444

row share mode, 444 share lock mode, 444 share row exclusive mode, 444

LOG function, 158 logarithms, returning, 158 logic errors, 378-379

nonterminating loops, 380 order of operations, 379

logical operators, 76-78

AND, 77 nulls, 89 syntax, 77 NOT, 76-77 nulls, 89 syntax, 76

OR, 77-78 expressions using, 78 nulls, 89

syntax, 77

login_denied exception, 208 logs, maintaining with trig-gers, 304-306

LONG datatype, 46

syntax, 46

LONG RAW datatype, 47

syntax, 47

LOOP loops, 144, 146

example, 144 EXIT statements with, 144 syntax, 143

loops, 121

CURSOR FOR, 254 debugging, 136 FOR, 121-122, 146 common errors, 124 EXIT statement, 140

listing, 121 nesting, 121 guidelines, 147 incrementing through, 123-124

listing, 123 infinite, 144, 380 jumping into (GOTO), 130 labels, 142-143

changing execution order, 143 listing, 142 syntax, 142 LOOP, 144, 146 example, 144 EXIT statements with, 144

syntax, 143 nesting, 148 order of execution, 125 REPEAT UNTIL, 144-146 example, 145 simulating, 145 reversing, 122-123 listing, 122 selecting, 146 spacing, 148 style tips, 148-149 FOR loop confusing style, 148 FOR loop suggested style, 148 terminating, 121, 138 WHILE, 134-135, 137-138, 146 examples, 134-135, 137-138

EXIT statement, 139 EXIT WHEN state-ment, 140

in functions, 137-138 stepping through, 136 syntax, 134

LOWER function, 157 LPAD function, 157 LTRIM function, 157 LUB function, 160

M MAP method, 366 MAX function, 160 messages

AQ (Advanced Queuing), 587

delay, 587 expiration, 587 repository, 588 queuing, 591 defining payload types, 591-592

placing messages in, 598-604

queue tables, creating, 592-595

queues, creating, 595-597 retrieving messages from, 604-608 starting/stopping, 597-598

methods, 336

accessor, 342 constructor, 341 referencing, 347 index-by tables, 271-274 MAP, 366

mutator, 342 ORDER, 364-366 publishing, calling Java from PL/SQL, 571-573 SELF parameter, 361-362 listing, 362

specifying, 362

678 locking

SSThresh calling from PL/SQL, 567-568

calling from SQL*Plus, 566-567 publishing, 565-566

MIN function, 160

minus sign (-)

negation operator, 65, 67 subtraction operator, 65

MLSLABEL datatype

defining output variables, 462

VARIABLE_VALUE pro-cedure, 469

MOD function, 158

MODE statement, 103

IN, 103

IN OUT, 103 OUT, 103

monitoring locks, 449

MONTHS_BETWEEN

function, 159, 182

syntax, 182

MSLABEL datatype

(syntax), 48

mutating tables (triggers),

320-323, 326-328

workaround example, 323-324

mutator methods, 342

mypi function listing, 107

N

naming

cursors, 247 functions, 101 pipes, 545 stored functions, 106

variables, 35 mixed case, 397 preceding with v_ or p_, 397

NCLOB datatype (National Character Large Object), 402

nested blocks, 15 nested tables, 274

declaring, 275 entries adding to, 275-278 removing, 279-281 extending, 277-278 initializing, 276-277

nesting

blocks, 54 listing, 54-55 FOR loops, 121 listing, 122 functions, 55-56

IF statements, 115-117 listing, 116 syntax, 115

vs IF ELSIF state-ment, 119 loops, 148 order of execution, 125 objects, 350

dot notation, 356-357 visibility, 358 procedures, 55-56

networks, performance (SQL limitations), 8 NEW_LINE procedure, 497 NEW_TIME function, 159, 183-184

syntax, 183

NEXTVAL pseudocolumns, 241

NEXT_DATE procedure, 521

NEXT_DAY function, 159, 179-181

syntax, 179

NEXT_ITEM_TYPE func-tion, 545

NLS parameters (jobs), 515 NLSSORT function, 157 NLS_CHARSET_ID func-tion, 160

NLS_CHARSET_NAME function, 160

NLS_INITCAP function, 157

NLS_LOWER function, 157 NLS_UPPER function, 157 non-query statements, 454, 456-460

binding variables, 455 closing cursor, 456 DBMS_SQL pkg and, 454 executing statements, 456 opening cursor, 454 parsing, 454-455

NOT operator, 76-77

nulls, 89 syntax, 76

Notepad, cutting and past-ing blocks from, 18 not_logged_on exception, 208

no_data_found exception,

208, 232 NULL statement (uses), 110 nulls

AND operator, 89 checking for, 90

IF statement, 90

in expressions, 86-89, 91 listing, 88

specifying alternate values, 91 three-valued logic, 87 treating as specific val-ues, 91

nulls 679

NOT operator, 89

OR operator, 89

NUMBER datatype, 38

defining output variables, 461

syntax, 39-40 VARIABLE_VALUE procedure, 468

NUMBER datatype:

subtypes, 40-41 number functions, 158

ABS, 158 ACOS, 158 ASIN, 158 ATAN, 158 ATAN2, 158 CEIL, 158 COS, 158 COSH, 158 EXP, 158 FLOOR, 158

LN, 158 LOG, 158 MOD, 158 POWER, 158 ROUND, 158 SIGN, 158 SIN, 158 SINH, 158 SQRT, 158 TAN, 158 TANH, 158 TRUNC, 158

numbers

absolute values, returning, 158

arc cosines, returning, 158 arc sines, returning, 158 arc tangents, returning, 158

converting to strings, 174-175

converting strings to, 159, 168-173

format masks, 169-170 NLS parameters, 170 converting to strings, 159 cosines, returning, 158 determining negative/

positive/zero, 158 dividing (returning remainders), 158 exponentiation, 158 factorials, 150 FACTORIAL function, 150

hyperbolic cosines, return-ing, 158

hyperbolic sines, return-ing, 158

hyperbolic tangents, returning, 158 logarithms, 158 raising to powers, 158 rounding, 158 sines, returning, 158 square roots, 158 tangents, returning, 158 truncating, 158

NVL function, 91, 160

O object identifiers, 349, 358 Object Navigator

(Procedure Builder), 24 object tables, 337, 349, 351-356

creating, 350 deleting objects from, 356

inserting objects, 351-352 retrieving/updating data, 352-356 versus column storage, 368

object types, 337

defining, 337, 339-343 accessor methods, 342 constructor methods, 341

mutator methods, 342 syntax, 340-341 methods, 368

see also classes

object views, 337 object-oriented

program-ming, see OOP

objects, 336

comparing, 363-366 MAP method, 366 ORDER method, 364-366 deleting from object tables, 356 instantiating, 336, 343-345 methods (SELF parame-ter), 361-362

nesting, 350 dot notation, 356-357 visibility, 358 Oracle limitations, 367 overloading functions, 363 package (private versus public), 205

referencing, 358-359, 361 DREF operator, 359, 361

object identifiers, 358 REF operator, 359, 361 retrieving

from columns, 347-349 from object tables, 352-353 storing

as columns, 345-347 object tables, 349, 351-356 updating from columns, 347-349 from object tables, 352-356

680 nulls

OOP (object-oriented

pro-gramming), 335-336

advantages, 336 attributes, 336 classes, 336 encapsulation, 334-335 benefits, 368 inheritance, 335 methods, 336 SELF parameter, 361-362 objects, 336 Oracle limitations, 367 overloading, 363 polymorphism, 335-336

OPEN command, 249

OPEN FOR statement,

258-259

opening cursors, 248-249

OPEN command, 249

opening files, 494

OPEN_CURSOR function,

454

operands, 64

operators, 64-73, 75-79

arithmetic, 65-67 addition (+), 65 division (/), 65 exponentiation (**), 65-66

identity (+), 65, 67 multiplication (*), 65 negation (-), 65, 67 subtraction (-), 65 binary, 65

comparison, 68-70, 72-74 BETWEEN, 68, 72 dates, 82-83 equality (=), 68

IN, 68, 72-73 inequality (!), 68 inequality (=), 68

IS NULL, 68, 74, 90 less than (<), 68

less than/equal to (<=), 68

LIKE, 68, 70-71 strings, 79-81 DREF, 359, 361 listing, 360 logical, 76-78 AND, 77 NOT, 76-77

OR, 77-78 order of execution (logic errors), 379

precedence, 84-85 parentheses, 85 REF, 359, 361 listing, 359 relational (sample expres-sions), 69

string, 78-79 concatenation (||), 78-79

LIKE, 78 unary, 65 VALUE, 354

OR operator, 77-78

expressions using, 78 nulls, 89

syntax, 77

Oracle

databases (obtaining for exercises), 12 Developer 2000 (Procedure Builder), 24-28

Web site, 12

Oracle Enterprise Server (SQLPlus Worksheet), 11 Oracle Technology Network,

see OTN

ORDER method, 364-366 order of operations (logic errors), 379

others exception, 208

OTN (Oracle Technology Network), 12

OUT arguments, calling Java from PL/SQL, 575-578

output variables

dbms output.put line() procedure, 17 defining, 461-463 CHAR datatype, 462 DATE datatype, 462 MLSLABEL datatype, 462

NUMBER datatype, 461

RAW datatype, 462 ROWID datatype, 462 VARCHAR2 datatype, 462

overloaded functions, 178 overloading, 363

advantages, 199-200 body, 199, 201-202 creating, 202-203 cursors, 256-257 return clause, 257 DBMS LOCK, 446-448 ALLOCATE_UNIQUE function, 446 CONVERT function, 447-448

RELEASE function, 448-449

REQUEST function, 446-447

SLEEP function, 449 DBMS OUTPUT, 25, 484 disabling, 485 enabling, 484-485 reading from, 487-490 writing to, 486-487 DBMS_ALERT, 532

see also alerts

DBMS_JOB, 510 overloading 681

DBMS_LOB external LOB func-tions, 406 internal LOB func-tions, 416 DBMS_OUTPUT, 491 debugging with, 383, 385

exceptions raised by, 491

DBMS_PIPE, 543-546 functions, 545, 555 procedures, 545, 553-555 DBMS_SQL anon blocks, 467, 469 error handling func-tions, 471 non-query statements,

454, 456-460 queries, 460-461, 463-467 DEBUG, 385-387 creating components, 386-387

DEBUG.ERASE pro-cedure, 388 DEBUG.OUT proce-dure, 387

declaring, 240-241 dependency, 206 guidelines, 200 invoking, 203 objects, private versus public, 205 packages, 199, 201-206 procedures, 197 recompiling, 204-205 specification, 199-200 variable declarations, 240

state, 205 subprograms, 199 calling, 203-204

TEXT IO, 25 UTL_FILE, 491, 496-497 clearing buffer, 500

P PACK_MESSAGE proce-dure, 545-547

PACK_MESSAGE_RAW procedure, 553-554 PACK_MESSAGE_ROWID procedure, 554

parameters

assigning values, 105 CREATE PROCEDURE command, 191 cursors

declaring, 248 initializing, 248 passing to, 247 scope, 256 defining, 102-103 referencing tables, 103 syntax, 103

dropping queue tables, 609

enqueuing messages, 602-604

event triggers, defining, 312

granting revoking queue access, 609

job definitions, 516 message queues, creating, 596-597

modes, 103

IN, 103

IN OUT, 103 OUT, 103 NLS (jobs), 515 Passing to functions, 111

procedures, 195 parameter definitions, 195

SELF, 361-362 listing, 362 specifying, 362 triggers, 298-299, 312-313, 318-319 condition, 299, 313, 318

correlation names, 299-300, 318 declarations, 299, 313, 318

instead-of, 318 pl/sql code, 299, 313, 318

table name, 299, 318 verb list, 298, 318

parentheses ( ), operator precedence, 85 PARSE procedure, 454 parsing statements, 454-455

queries, 461

payload, AQ (Advanced Queuing), 587 payload types, defining (message queuing), 591-592

percent sign (%) (wildcard character), 70

performance, network (SQL limitations), 8

pipes

clearing message buffer, 554

creating, 546, 550-551 moving messages to buffer, 548 multiple sessions, 544 naming, 545

operation of, 544 private, 544 public, 543

682 overloading

RAW data PACK_MESSAGE_

RAW procedure, 553-554 UNPACK_

MESSAGE_RAW procedure, 554 readers, 543 reading data from, 551-553 removing, 549-550, 553 removing all data from, 555

retrieving message from buffer, 548-549 rowids

decoding, 554 sending, 554 sending data to, 547 size, 545

versus alerts, 555-557 writers, 543

PL/SQL, 10

block structure, 13 compiling and execut-ing blocks, 15-17 syntax, 14-15 blocks, alternatives to retyping, 18-20 calling from Java (SQLJ), 578-579

calling procedures and functions, 580, 582 executing blocks, 578-579 calling Java from, 569 datatype compatibility, 574-575

Employee class, 569-570 methods, publishing, 571-573

OUT and IN OUT arguments, 575-578

calling methods (SSThresh), 567-568 output (dbms output.put line() procedure), 17 processing benefits, 9

platform independence (PL/SQL benefits), 9 Platinum Technology Inc.

Web site, 11 PLS_INTEGER datatype, 43

syntax, 44

plus sign (+)

addition operator, 65 identity operator, 65, 67

pointers (cursors), 246

pointers, see locators

polling (alerts), setting time interval, 536

polymorphism, 335-336 portability (PL/SQL bene-fits), 9

POWER function, 158 powers, raising numbers to, 158

precedence, operators, 84-85

parentheses, 85

predefined exceptions

invalid_cursor, 232 no_data_found, 232 too_many_rows, 232 value_error, 232 when_others, 232

predefined Oracle errors, 207-209

cursor_already_open, 208 dup_val_on_index, 208 invalid_cursor, 208 invalid_number, 208 login_denied, 208

not_logged_on, 208 no_data_found, 208 others, 208 program_error, 208 storage_error, 208 timeout_on_resource, 208 too_many_rows, 208 transaction_backed_out, 208

value_error, 208 zero_divide, 208

private objects (packages), 205

private pipes, 544

creating, 546, 550-551

privileges, database (exer-cise completion require-ments), 12

Procedural Language/ Structured Query

Language, see PL/SQL

procedural languages, 10 procedure blocks, 51

syntax, 52-53

Procedure Builder (Oracle Developer 2000), 24-28

database connections, 27-28

PL/SQL interpreter, 25-26

SS THRESH function, creating, 26 starting, 24

procedures, 190, 192-195,

197, 199

AQ (Advanced Queueing), 608

dropping queue tables, 609

dropping queues, 608 queue access, granting/revoking, 609-610

BROKEN, 522 procedures 683

CHANGE, 520 CLOSE_CURSOR, 456 COLUMN_VALUE, 463 creating, 190, 192 debugging information, 193

declarative part, 190 defining, 52-53 listing, 53 dependencies, discovering, 192

exception-handling part, 190

executable part, 190 FCLOSE, exceptions raised by, 494 FCLOSEALL, exceptions raised by, 494

FCLOSE_ALL, 494 FFLUSH, 500 exceptions raised by, 498

INTERVAL, 521 nesting, 55-56 NEW_LINE, 497 NEXT_DATE, 521 overloading, 197 PACK_MESSAGE, 545-547

PACK_MESSAGE_RAW, 553-554

PACK_MESSAGE_

ROWID, 554 parameters (definitions), 195

PARSE, 454 PURGE, 545, 555 PUT, 497 exceptions raised by, 498

PUTF, 498 exceptions raised by, 498

PUT_LINE, 498 exceptions raised by, 498

re-creating, 194 listing, 194 recursive, 197, 199 terminating conditions, 198

REGISTER, 534 REMOVE, 535 REMOVEALL, 536 replacing, 194 RESET_BUFFER, 545, 554

RETURN statement, 192 RUN, 514-515

SET_DEFAULTS, 536 SIGNAL, 533 stored, 190 creating, 191 dropping, 197 invoking, 194, 199 listing information, 195 recompiling, 193-194 SUBMIT, 512, 514 parameters, 512 swapn (listing), 57-58 UNPACK_MESSAGE,

545, 548-549 UNPACK_MESSAGE_

RAW, 554 UNPACK_MESSAGE_

ROWID, 554 uses, 190 VARIABLE_VALUE CHAR datatype, 468 DATE datatype, 468 MLSLABEL datatype, 469

NUMBER datatype, 468

RAW datatype, 468 ROWID datatype, 469 VARCHAR2 datatype, 468

versus functions, 190 WAITANY, 535 WAITONE, 534 WHAT, 521

processing (PL/SQL bene-fits), 9

producers, 586

AQ (Advanced Queuing), 587

program code, see listings

program_error exception, 208

propagate exceptions, 214 propagation, AQ (Advanced Queuing), 587-588 pseudocolumns, 241

CURRVAL and NEXTVAL, 241 ROWID, 242 ROWNUM, 242

public objects (packages), 205

public pipes, 543

creating, 550-551

publishing

methods, calling Java from PL/SQL, 571-573 SSThresh method, creat-ing Java procedures, 565-566

PURGE procedure, 545, 555 PUT command, 193 PUT procedure, 497

exceptions raised by, 498

PUTF procedure, 498

exceptions raised by, 498

PUT_LINE command, 193

listing, 193

PUT_LINE procedure, 498

exceptions raised by, 498

684 procedures

queries, 460-461, 463-467

binding variables, 461 closing cursor, 466 counting rows returned, 160

defining output variables, 461-463

CHAR datatype, 462 DATE datatype, 462 RAW datatype, 462 ROWID datatype, 462 executing (SQL*Plus), 10 executing statements, 463 fetching rows, 463 parsing statements, 461 reading results into vari-ables, 463-465 SELECT statement exam-ple, 466-467

Quest Software Web site, 11

queuing

AQ (Advanced Queuing), 585-586, 608

agents, 587 consumers, 587 control data, 587 deferred messaging0, 587

delay, 587 dequeue, 587 disconnected messag-ing, 587

dropping queue tables, 609

dropping queues, 608 enqueue, 587 granting/revoking access, 609-610 message repository, 588

messages, 587

expiration, 587 payload, 587 producers, 587 propagation, 587-588 sample scenario, 590 server configuration, 588-589

transaction support, 588

transparency, 588 message queuing, 591 defining payload types, 591-592

queue tables, creating, 592-595

queues, creating, 595-597 placing messages in queues, 598, 602 parameters, 602-604 record types, 599-602 retrieving messages from queues, 604, 606 dequeuing change mes-sages, 606-608 record types, 604-606 starting/stopping queues, 597-598

R raising exceptions, 214 RAW datatype, 46

defining output variables, 462

syntax, 47 VARIABLE_VALUE pro-cedure, 468

RAWTOHEX function, 159 READ function (LOBs),

416, 421

BFILE, 406, 411

read-only transactions, 438 read-write transactions, 438 readers (pipes), 543 reading from DBMS OUT-PUT package (syntax), 487-490

RECEIVE_MESSAGE function, 545, 548 recompiling

packages, 204-205 stored procedures, 193-194

record variables

%rowtype attribute, 236 cursor-based, 239 declaring, 234-235 table-based, 236

records

attributes (%TYPE), 235-236

dequeuing messages, 604 DEQUEUE_OPTIONS _T, 605-606

enqueing messages, 599-602

AQ$_AGENT, 601 AQ$_RECIPIENT_ LIST_T, 602 ENQUEUE_OPTIONS _T, 600

referencing fields (dot notation), 237

recursive functions, 149

FACTORIAL, 150 testing, 151 uses, 152

recursive procedures, 197, 199

terminating conditions, 198

REF cursor type (declaring

in packages), 260 REF operator, 359, 361

listing, 359 REF operator 685

objects, 358-359, 361 DREF operator, 359, 361

object identifiers, 358 REF operator, 359, 361 values (index-by tables), 268-269

REGISTER procedure, 534 relational operators (sample expressions), 69

RELEASE function (DBMS LOCK package), 448-449 remainders (division), returning, 158 REMOVE procedure, 535 REMOVEALL procedure, 536

REMOVE_PIPE function,

545, 549-550 removing

classes (SSConstants), 568-569

data (varrays), 283-284 jobs, 520

pipes, 549-550, 553

REPEAT UNTIL loops, 144-146

example, 145 simulating, 145

REPLACE function, 157 Repositories, message (AQ), 588

REQUEST function (DBMS LOCK package), 446-447 requirements (completing exercises), 12

RESET_BUFFER proce-dure, 545, 554

retrieving objects

from columns, 347-349 from object tables, 352-353

return data types, 105 RETURN statement, 101, 192

return values, function, dis-playing, 23

retyping blocks (alterna-tives), 18-20

REVERSE keyword (loops), 122-123

revoking access queues (AQ), 609-610 ROLLBACK command, 441 ROLLBACK statements, 234

rolling back transactions,

438, 441

ROLLBACK command, 441

savepoints, 441-442

ROUND function, 158-159, 184-185

format masks, 177 syntax, 184-185

rounding numbers, 158 ROW ID, converting to string, 159

row-level triggers, 296 ROWID datatype

defining output variables, 462

syntax, 47-48 VARIABLE_VALUE pro-cedure, 469

ROWID pseudocolumns, 242

ROWIDTOCHAR function, 159

ROWNUM pseudocolumns, 242

rows

counting number returned, 160

fetching into buffer, 463

inserting, 226-229 employee table exam-ple, 227, 229 locking, 445

RPAD function, 157 RTRIM function, 157 RUN procedure, 514-515

S SAVEPOINT statements, 234

savepoints, 441-442 saving address objects in tables, 346

scalar variables, 34 scientific notation, 174 scope, 58

cursors, 262 exceptions, 214 listing, 58-59

SELECT FUNCTION com-mand, 161

SELECT statement, 223, 229-230

examples, 229-230 exceptions, 232 syntax, 229, 233

SELF parameter, 361-362

listing, 362 specifying, 362

SEND_MESSAGE function,

545, 547 Server Manager, 11 servers

configuring for AQ (Advanced Queuing), 588-589

PL/SQL processing bene-fits, 9

SET SERVEROUTPUT ON statement, 108

686 referencing

SET TRANSACTION

com-mand, 439

SET TRANSACTION

state-ments, 234

SET_DEFAULTS

proce-dure, 536

SHUTDOWN trigger

(list-ing), 315

SIGN function, 158

SIGNAL procedure, 533

SIN function, 158

sines, returning, 158

hyperbolic, 158 inverse, 158

SINH function, 158

slash (/), 65

SLEEP function (DBMS

LOCK package), 449

SNP parameters, 511

software (exercise

comple-tion requirements), 12

SOUNDEX function, 157

SQL, 9

limitations, 8

SQL*Plus

@ command, 18-19 calling methods (SSThresh), 566-567 EDIT command, 19-20 interactivity, 10 entering statements, 10 executing queries, 10 Server Manager, 11

SQL-Navigator (Quest

Software), 11

SQL-Programmer (Sylvain

Faust Inc.), 11

SQL-Station (Platinum

Technology Inc.), 11

SQLCODE function, 160,

211-212

SQLERRM function, 160,

211-212

SQLJ, calling PL/SQL from Java, 578-579

calling procedures and functions, 580, 582 executing blocks, 578-579

SQLPlus Worksheet, 11, 28

executing blocks, 28-29

SQRT function, 158 square roots, 158 squareme function listing, 110

SS CONSTANTS class, cre-ating Java procedures, 562-563

SS THRESH function

creating (Procedure Builder), 26 listing, 20 with an error, 21

SSConstants class, removing from databases, 568-569 SSThresh function, 563

listing, 100

SSThresh method

calling from PL/SQL, 567-568

calling from SQL*Plus, 566-567

publishing, 565-566

starting

Procedure Builder (Oracle Developer 2000), 24 queues, 597-598

starting transactions, 438-439

SET TRANSACTION command, 439

STARTUP triggers (listing), 315

statement labels, 128

accessing, 128 format, 128

statement-level triggers, 296 statements

BEGIN, 101 bulk-binding, 284 BULK COLLECT key-word, 285-286 FORALL keyword, 286-288

COMMIT, 440 CREATE FUNCTION, 26 CREATE TABLE, 224 DELETE, 223 syntax, 231 DML (LOCK TABLE), 233

END, 101 EXCEPTION, 101, 106 executing, 456

for queries, 463 EXIT, 138-142 changing loop execution order, 143

with FOR loop, 140 with WHILE loop, 139 within functions, 141 EXIT WHEN, 138-142 syntax, 138 with WHILE loop, 140 FETCH (INTO clause), 259

GOTO, 128-129, 131-132, 134

disadvantages, 133-134 example, 133

scoping rules, 129,

131, 133 syntax, 128

IF, 112-113 common errors, 120 formatting, 119-120 jumping into (GOTO), 131

jumping within (GOTO), 131-133 statements 687