A development approach to embed parametrized SQL statements in software applications. For more details, please visit this link https://www.researchgate.net/publication/4144158_SQL_Statement_Template_a_development_approach_for_database-driven_applications

1. SQL Statement Template: A Development
Approach for Database-Driven
Applications
Osama M. Khaled
The American University in Cairo
okhaled@aucegypt.edu
Hoda M. Hosny
The American University in Cairo
hhosny@aucegypt.edu

2. OUTLINE
 Background
 Domain Analysis
 Roles & Responsibilities
 SQL Statement Template Definition
Language
 Example

3. BACKGROUND
 Brief History about DB.
 Database role in application
development.
 SQL Statement Externalization.
– Sun DAO Design Pattern
– Business Objects

4. DOMAIN ANALYSIS
 Defects of bundling SQL statements inside the
application code.
– SQL maintenance requires code recompilation.
– Deviating focus of application developer.
– Readability and understandability decreases.
– DB experts cannot easily read SQL statements inside the
code.

5. DOMAIN ANALYSIS
Considered Design
Issues
StandardizationMaintainability
ComplexityReusability

6. ROLES & RESPONSIBILITIES
 Why build SQL statements in design phase.
– DB designer has fresh knowledge about
architecture.
– Helps refining DB design.
– Guarantees consistent SQL statements.
– Implementers will focus more on functional
requirements.
– Speeds up development process.
– DB is a product in itself.

7. ROLES & RESPONSIBILITIES
Design Phase activities
R
esponsible
for

8. ROLES & RESPONSIBILITIES
Implementation
R
esponsible
for
Usual
Implementation
Activities
Maintain,
Develop, and
Test SQL
Statement
Templates

9. ROLES & RESPONSIBILITIES
Affected parties
DB Admin System Administrator
System Support
SQL Statement Templates Files
REVIEW
FOR
OPTIMIZATION
Figure out SQL
problems easily
Resolve bugs

10. SQL STATEMENT TEMPLATE
DEFINITION LANGUAGE
 SQL Statements Construction
complexity.
Type Example
No replaceable
value
SELECT *
FROM INVOICES
WHERE
INVOICE_TYPE = 1
AND PRICE > 30
Replaceable value
only
SELECT *
FROM INVOICES
WHERE
INVOICE_TYPE = $INVOICE_TYPE$
AND PRICE > $MIN_PRICE$
Replaceable SQL
constructs
SELECT
--$all$ *
--$invoice_number$ inv_no
FROM
INVOICES
--$inv_type$ WHERE INVOICE_TYPE = $INVOICE_TYPE$
--$min_price$ WHERE PRICE > $MIN_PRICE$

11. SQL STATEMENT TEMPLATE
DEFINITION LANGUAGE
 Describing the language
 Benefits of using this language
– People with database background are more familiar with this
structure.
– Easy to edit with SQL editors.
– Can support easily the third type of the SQL statements
complexities.
– Can be converted easily to XML.
– Definition semantics
– Documentation
– Implementation complexity.

12. EXAMPLE
SELECT
U.ACTIVITY_NAME AS NUM1,
TO_CHAR(COUNT(*)) AS VALUE
FROM
ACTIVITY U
WHERE
U.EMPLOYEE_ID = $employee_id$
GROUP BY U.ACTIVITY_NAME ORDER BY COUNT(*) DESC

13. EXAMPLE
SELECT
U.ACTIVITY_NAME AS NUM1,
TO_CHAR(SUM(U.ROUNDED_VOLUME)) AS VALUE
FROM
ACTIVITY U,
GROUPS G,
EMPLOYEE_GROUPS CG
WHERE
U.EMPOLOYEE_ID = $employee_id$ AND
CV.ACTIVITY_TYPE = ’$activity_type$’ AND
CG.EMPLOYEE_KEY = G.EMPLOYEE_KEY AND
CG.GROUPS_KEY = G.GROUPS_KEY AND
U.ACTIVITY_KEY = CG.CACTIVITY_KEY AND
G.EMPLOYEE_KEY = $employee_key$ AND
G.GROUPS_KEY = $group_key$
GROUP BY U.ACTIVITY_NAME ORDER BY
SUM(U.ROUNDED_VOLUME) DESC

14. EXAMPLE
 --@begin ACTIVITY_ACCESS
 --@group ACTIVITIES
 SELECT
 --$ achievement $ U.ACTIVITY_NAME AS NUM1,
 --$ achievement $ TO_CHAR(COUNT(*)) AS VALUE
 --$cost$ U.ACTIVITY_NAME AS NUM1,
 --$cost$TO_CHAR(SUM(U.RATED_AMOUNT)) AS VALUE
 --$dur$ U.ACTIVITY_NAME AS NUM1,
 --$dur$ TO_CHAR(SUM(U.ROUNDED_VOLUME)) AS VALUE
 FROM ACTIVITY U
 WHERE U.EMPLOYEE_ID = $employee_id$
 --$achievement$ GROUP BY U.ACTIVITY_NAME
 --$achievement$ ORDER BY COUNT(*) DESC
 --$cost$ GROUP BY U.ACTIVITY_NAME
 --$cost$ ORDER BY SUM(U.RATED_AMOUNT) DESC
 --$dur$ GROUP BY U.ACTIVITY_NAME
 --$dur$ ORDER BY SUM(U.ROUNDED_VOLUME) DESC
 --@end ACTIVITY_ACCESS

15. EXAMPLE
 SQLBlock sqlBlock = SQLIndexer().
 getSQL("ACTIVITY_ACCESS");
 // enable where keyword
 sqlBlock.setTagValue("employee_id",
employee_id);
 // report_type is acheivement, cost, or dur
 sqlBlock.clearCommentTag(report_type);
 Vector result =
select(sqlBlock.getRuntimeSql());

16. QUESTIONS