Interface CountDSLCompleter

All Superinterfaces:
Function<CountDSL<SelectModel>, Buildable<SelectModel>>
Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@FunctionalInterface public interface CountDSLCompleter extends Function<CountDSL<SelectModel>, Buildable<SelectModel>>
Represents a function that can be used to create a general count method. When using this function, you can create a method that does not require a user to call the build() and render() methods - making client code look a bit cleaner.

This function is intended to by used in conjunction with a utility method like MyBatis3Utils.countFrom(ToLongFunction, CountDSL, CountDSLCompleter)

For example, you can create mapper interface methods like this: 

@SelectProvider(type=SqlProviderAdapter.class, method="select")
long count(SelectStatementProvider selectStatement);

default long count(CountDSLCompleter completer) {
    return MyBatis3Utils.count(this::count, person, completer);
}

And then call the simplified default method like this: 

long rows = mapper.count(c ->
        c.where(occupation, isNull()));

You can implement a "count all" with the following code: 

long rows = mapper.count(c -> c);

Or 

long rows = mapper.count(CountDSLCompleter.allRows());
Author:
Jeff Butler

  • Method Details

    • allRows

      static CountDSLCompleter allRows()
      Returns a completer that can be used to count every row in a table.
      Returns:
      the completer that will count every row in a table