Using the Table API

Standard Uses of API• Populate Columns via Sequences• Insert Default Values instead of nulls• Populate Autogen Columns

– Date Created, Date Modified– Who Created, Who Modified– Sequence within Parent

• Force Uppercase• Domain Validation• Arc validation

Standard Uses of API

• Foreign Key Cascades, Nullifies, Defaults, Restricted Delete/Update

• Table Journaling• Derived Columns• Denormalization:

– Copy Parent Value to Child– Aggregate Child Values to Parent

Specification SummarySequence Populated

Denormalized

Uppercase

Domain

Autogen

Force Uppercase

• Set ‘Uppercase’ to Yes• Set ‘Server Derived?’ to Yes• Generate Table API

Uppercase Only

Uppercase

Server Derived?

Autogen Code

• For autogen column– Set Autogen Type

• Date Modified/Created• Created/Modified By• Sequence within Parent

– Set ‘Server Derived’ to Yes.

• Generate API

Autogen Columns

Server Derived?

Autogen Type

Domain Validation

• Via Check Constraint (non-API)• Via Lookup in CG_REF_CODES table• How?

– Define Domain– Define Column using Domain, or– Define Column with ‘Allowable Values’– Generate Table API

Server

Packages

Validating DomainsGAME_CATEGORY

ARC

RV_DOMAIN RV_LOW_VALUE

GAME _CATEGORY ARCGAME _CATEGORY EDUGAME _CATEGORY ROLGAME _CATEGORY SIM

Triggers

CG_REF_CODESCG_REF_CODES

DML

TITLESTITLES

Advantages of REF_CODES

• DBA must alter Check constraint• May have to bring down system • CG_REF_CODES table can be

accessed thru Application

Schema of CG_REF_CODES• RV_DOMAIN

– Domain name, or– Table.column

• RV_LOW_VALUE– One legal value, e.g., UT– Low value of a range

• RV_HIGH_VALUE• RV_ABBREVIATION, e.g., UNIT• RV_MEANING, e.g., Unit Test

Domain Validation

Domain Validation

Server Derived?

Domain

How to Populate with Sequence

• Make sure sequence is defined• For Populated Column:

– Set ‘Sequence’ to desired sequence

• Generate API

Populate with Sequence

Server Derived?

SequenceSequence Defined

Validating Arcs

GAMES

# * PRODUCT_CODE. . .

TITLES

# * PRODUCT_CODE * TITLE

. . . o MO_PRODUCT_CODE o GA_PRODUCT_CODE . . .

MOVIES

# * PRODUCT_CODE. . .DML

TriggersServer

Packages

Arc Validation

• Explicit style only: one column for each FK in Arc

• For each FK in Table with Arc,– Set ‘Arc Number’ same for same arc– Set ‘Arc Mandatory’ to Yes or No

• Generate Table API for Table

Performing Cascade Update

Triggers

PRODUCT_CODE

25

TI_PRODUCT_CODE

2525

TITLESTITLES COPIESCOPIES

Update 30

Server

Packages

3030

Cascading Updates/Deletes

• For foreign key,– Set ‘Update Rule’– Set ‘Delete Rule’– Set ‘Validate In’ to Server or Both

• Generate Table API for Parent and Child at Same Time

• Usually best to generate whole API at one time

Foreign Key Cascade

FK properties (NOT FK Column)

Delete Rule

Validate in Server

Journal Tables

• Have all fields of Base Table• Plus: operation, date, user,

application• Contains only needed table data

– Key for deletes– Key plus updated columns for

updates

Server

Packages

Journaling Tables

PRODUCT_CODE . . .

TITLESTITLES

PRODUCT_CODE . . .

TITLES_JNTITLES_JNTriggers

DML 30

30

To Set Up Journaling

• Table Property: ‘Journal’• Set to

– ‘Server’– or ‘Client Calls Server Procedure’

• Generate API

Denormalization

• Most Common: Bring Parent Value (e.g., Department Name) into Child Column (e.g., Employee Table)

• Aggregate Children (Count, Sum, Average of Child Column)

Copying Denormalized Values

PRODUCT_CODE TITLE

30 TITANIC

TITLESTITLES

TI_PRODUCT_CODE TITLE

COPIESCOPIES

By foreign keyBy foreign key

DML

30

Server

Packages

TITANIC

Triggers

How To Denormalize into Child

• In Child table, for target column– Set ‘From Column’ to column in

Parent.– Set ‘Via Foreign Key’ as appropriate.– Set ‘Server Derived’ to Yes

• Generate API for both parent and child.

Denormalization

. . .

How to Aggregate into Parent

• For target column in parent– Set ‘From Column’– Set ‘Via Foreign Key’– Set ‘Using Operator’ (Count, Sum,

etc.)– Set ‘Server Derived’ to Yes

• Generate API for Parent and Child

Column Derivations• Calculate value based on columns

in the same record– Area := Height * Width– Name := Lname || ‘, ‘ || Fname

• For target column– set ‘Derivation Expression Type’ to

SQL Expression– Enter ‘Derivation Expression’– Set Server Derived to Yes

• Generate API

Specification SummarySequence Populated

Denormalized

Uppercase

Domain

Autogen

Generate DB from Server Model

REF_CODES Table CreatedPROMPT Creating Table 'CG_REF_CODES'CREATE TABLE CG_REF_CODES (RV_DOMAIN VARCHAR2(100) NOT NULL ,RV_LOW_VALUE VARCHAR2(240) NOT NULL ,RV_HIGH_VALUE VARCHAR2(240) ,RV_ABBREVIATION VARCHAR2(240) ,RV_MEANING VARCHAR2(240) )/

REF_CODES Table Populated

DELETE FROM CG_REF_CODESWHERE RV_DOMAIN = 'PCH_TYPE_TYPE'/INSERT INTO CG_REF_CODES (RV_DOMAIN, …)VALUES ('PCH_TYPE_TYPE', 'OT', NULL, 'OTHER', 'Other')/INSERT INTO CG_REF_CODES (RV_DOMAIN, …)VALUES ('PCH_TYPE_TYPE', 'EQ', NULL, 'EQUIP', 'Equipment over $500')/. . .

Generate Table API

Some Messages for Purchases

Creating Table API Error Package CG$ERRORS ...Creating Table API Package Specification for Table 'PURCHASES' ......Creating Table API Package Body for Table 'PURCHASES' ......Creating Trigger Logic for Table 'PURCHASES' ...Creating Before Delete Statement Trigger on 'PURCHASES' ...Creating Before Delete Row Trigger on 'PURCHASES' ...Creating After Delete Row Trigger on 'PURCHASES' ...Creating After Delete Statement Trigger on 'PURCHASES' ...

Package Spec

• Trigger flag to avoid recursive call• Useful Constants• Row variable for Table• Table variable for Table• Procedures ins, upd, del, lck, slct• Procedures for validating arc,

domains, cascading, denormalization

Up_autogen_columns-- Code highlights IF (operation = 'INS') THEN BEGIN IF (cg$rec.PURCHASES_ID is NULL) THEN -- SEQUENCE SELECT PCH_SEQ.nextval INTO cg$rec.PURCHASES_ID FROM DUAL; END IF; EXCEPTION WHEN OTHERS THEN cg$errors.push(SQLERRM, ….) cg$errors.raise_failure; END;

cg$rec.CREATOR := user; -- AUTOGEN cg$rec.CREATEDATE := trunc(sysdate); END IF; cg$rec.ITEM := upper(cg$rec.ITEM); -- UPPERCASE IF(cg$rec.PCH_DNUMBER IS NULL) THEN cg$rec.DNAME := NULL; ELSE SELECT DNAME INTO cg$rec.DNAME -- DENORMALIZATION FROM DEPARTMENTS WHERE DNUMBER = cg$rec.PCH_DNUMBER; END IF;

Test With SQLPLUSSQL> insert into purchases( 2 PURCHASES_ID,PCH_DNUMBER,DNAME,ITEM,PCH_TYPE,QUANTITY,COST, 3 CREATOR,CREATEDATE) 4 values( 5 null, 10, null, 'soap', 'SU', 1, 10, 6 null,null);

ID DNO DNAME ITEM PC QTY COST CREATOR CREATEDAT---- ---- --------------- ----- -- ---- ---- ---------- --------- 5 10 ADMINISTRATION SOAP SU 1 10 IBL 16-APR-00

Test with Form