echebbi / datatable Goto Github PK

As of now, calling a method with improper arguments leads to a non-explicit exception.

This must be replaced by either

• a fail fast behavior with custom exceptions,
• data structures like Try and Optional

The Query DSL does not allow to express easily OR conditions.

For instance, in order to keep the rows where the value of the column "A" is either null or a string in lower case, we have to write :

Query
    .select()
    .from(table)
    .where("A").asStr().match(str -> str == null || str.equals(str.toLowerCase());

The built-in methods such as isInstanceOf,in or isTrue cannot be used anymore and must be re-written by the user.

It would be better to write something like :

Query
    .select()
    .from(table)
    .where("A").isNull().or().asStr().isInLowerCase();

or even :

Query
    .select()
    .from(table)
    .where("A").asStr().match(str -> str.isNull() || str.isInLowerCase());

instead.

Either way, the current DSL makes predicate composition difficult and should be adapted.

Current classes are not tested.

It would be great to add some tests in order to validate current implementation and to avoid possible regressions in future commits.

The following code:

Query
    .from(people)
    .where(n(AGE));

does not compile with javac. The compiler is complaining that:

the method where is ambiguous: the methods 
    where(ColumnId<T>),
    where(ColumnOfNumbers<T>)

both match

Considering that:

• n clearly returns a ColumnOfNumbers,
• ColumnOfNumbers inherits from ColumnId
• Eclipse is able to find to method to call,

I'd assume that javac was able to manage this situation... Apparently not.

As of now, the library cannot be set as a dependency through POM.xml

This should be fixed once code coverage becomes sufficient.