We usually put createCriteria() within a Grails services. In Grails, createCriteria() come with any domain object, and it return a type BuildableCriteria. Most often, we call its list() method to return a list of that domain object. Here is a code copy from the Grails document site:
def c = Account.createCriteria() def results = c.list { like("holderFirstName", "Fred%") and { between("balance", 500, 1000) eq("branch", "London") } maxResults(10) order("holderLastName", "desc") }
We put the query inside list{…}. In this example, the result would be a List<Account> that has holderFirstName like Fred%, with 500< balance < 1000, and the list will order by holderLastName in descending fashion.
It has 4 methods list, get, scroll,listDistinct. The mostly use ones are list, and get. The method get get one record, and the list method get a list of the related domain object.
Criterion Method are those method that we put inside the {…} to query the data source. The following list is copy from http://docs.grails.org/3.1.1/ref/Domain%20Classes/createCriteria.html. Should go there to see for details. The common ones would be eq, like, ilike, gt, ge, …
between("balance", 500, 1000) eq("branch", "London") eq("branch", "london", [ignoreCase: true]) eqProperty("lastTx", "firstTx") gt("balance",1000) gtProperty("balance", "overdraft") ge("balance", 1000) geProperty("balance", "overdraft") idEq(1) ilike("holderFirstName", "Steph%") 'in'("age",[18..65]) or not {'in'("age",[18..65])} isEmpty("transactions") isNotEmpty("transactions") isNull("holderGender") isNotNull("holderGender") lt("balance", 1000) ltProperty("balance", "overdraft") le("balance", 1000) leProperty("balance", "overdraft") like("holderFirstName", "Steph%") ne("branch", "London") neProperty("lastTx", "firstTx") order("holderLastName", "desc") rlike("holderFirstName", /Steph.+/) sizeEq("transactions", 10) sizeGt("transactions", 10) sizeGe("transactions", 10) sizeLt("transactions", 10) sizeLe("transactions", 10) sizeNe("transactions", 10)
order("age", "desc") firstResult(20) maxResults(10) cache(boolean)