how can i make a search form through which i can fetch data ?

1. create local variables for each text field as null,

2. the variable you create to hold those values:

i'm assuming that you have created a cdt

local!filter: 'type!{urn:com:appian:types}CDT_TYPE_EXAMPLE'(
firstName: local!firstName,
lastName: local!lastName,
location: local!location,
applicationType: local!applicationType,
applicationStatus: local!applicationStatus,
fromDate: local!fromDate,
toDate: local!toDate
)

3. each textField you need to save them using "saveInto" from textField properties

4. create a local variable to hold your data from an expression rule which is querying through your database.

5. you will have something like this:

local!data: rule!EXPRESSION_RULE_QUERY_DATABASE(
firstName: local!firstName,
lastName: local!lastName,
location: local!location,
applicationType: local!applicationType,
applicationStatus: local!applicationStatus,
fromDate: local!fromDate,
toDate: local!toDate
)

The reason for doing this is letting your search be more dynamic