Oracle SQL query without all parameters

Question

Got this sql (selection between ranks):

//Variables come from outside or other classes etc... 
"SELECT * from users where dept_name= ? AND birth_date >=? AND birth_date <=? AND money >=? AND money <=?;  
//Long preparedStatement code...

Using the next code to pass dept_name to the sql:

System.out.println("Insert department name: ");
Scanner alpha = new Scanner(System.in);
String dept_name= alpha.nextLine();

What happens if I don't insert anything on the scanner and I simply press enter? Like if I want to skip the search by dept_name and I only want to search between birth_date and money ranks?

How can I handle:

pstmt.setString(1, users.getDeptname()); //prepared statement

If it previously received a "enter" as character on the dept_id ?

How can Oracle ignore dept_name =? if no valor is passed in the "?" with prepared statement and use the next fields in the SQL to continue the query?

a1ex07 · Accepted Answer · 2014-09-18 17:40:34Z

1

You can modify the query to something like

SELECT * FROM users 
WHERE (dept_name = ? OR ? IS NULL) AND .....

Then in the code you setting pstmt.setString(1, dept_name); pstmt.setString(2,dept_name);

However, I'd rather have multiple statements then one that fits all. The problem with any universal approach is performance. Optimizer will not be able to generate good execution plan . For instance, if username is set, range/unique scan of underlying index is definitely preferable over full table scan. Even though Oracle 11 and higher has nice features like bind awareness, I'm not 100% sure it will handle all the cases in optimal way.

edited Sep 18, 2014 at 17:40

answered Sep 18, 2014 at 17:34

a1ex07

37.4k12 gold badges93 silver badges103 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Oracle SQL query without all parameters

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related