find
目的 Purpose
Finds the first matching result for the given query or null if no instance is found使用例 Examples
// Dan brown's first book Book.find("from Book as b where b.author='Dan Brown'")// with a positional parameter Book.find("from Book as b where b.author=?", ['Dan Brown'])// with a named parameter Book.find("from Book as b where b.author=:author", [author: 'Dan Brown'])// use the query cache Book.find("from Book as b where b.author='Dan Brown'", [cache: true]) Book.find("from Book as b where b.author=:author", [author: 'Dan Brown'], [cache: true])// query by example def example = new Book(author: "Dan Brown") Book.find(example)// Using where criteria (since Grails 2.0) Person p = Person.find { firstName == "Bart" }
詳細 Description
The find method allows querying with Hibernate's query language HQL and querying by example. The basic syntax is:Book.find(String query) Book.find(String query, Collection positionalParams) Book.find(String query, Collection positionalParams, Map queryParams) Book.find(String query, Map namedParams) Book.find(String query, Map namedParams, Map queryParams) Book.find(Book example) Book.find(Closure whereCriteria)
Parameters:
query- An HQL querypositionalParams- AListof parameters for a positional parametrized HQL querynamedParams- AMapof named parameters a HQL queryqueryParams- AMapof query parameters. Currently, onlycacheis supportedexample- An instance of the domain class for query by example