A comparison of experimental query languages. The example numbering is based on QueryLanguageComparison. 

Motivation for this topic is covered in ExperimentalQueryLanguageDiscussion.

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Experimental Query Languages:
* SMEQL - TqlRoadmap, Structured Meta-Enabled Query Language

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'''Example 1:''' Retrieve all columns/attributes and rows/tuples from a table/RelVar

SMEQL (TqlRoadmap):
 calc(myThings, [])
 // or
 filter(myThings, 1=1)

'''Example 2:''' Restriction

SMEQL:
 filter(myThings, name='blah')

'''Example 3:''' Restriction and projection with unique result

SMEQL:
 T1 = filter(myThings, name='blah')  
 T2 = calc(T1, [A, B, C])
 unique(T2)
 //
 // nested style
 //
 unique(calc(filter(myThings, name='blah'), [A, B, C]))

'''Example 3b:''' Restriction and projection without required uniqueness

SMEQL:
 T1 = filter(myThings, name='blah')  
 calc(T1, [A, B, C])
 //
 // nested style
 //
 calc(filter(myThings, name='blah'), [A, B, C])


'''Example 4''': Aggregation

SMEQL:
 group(sp, [snumber, count() p_count])

'''Example 5''': Insertion

SMEQL:
 insert(myThings, [(1)a,(2)b,(3)c,('glub')name])
 insert(myThings, [(4)a,(5)b,(6)c,('glob')name])
* Note how the value listing uses the same syntax as "Calc" (roughly a SELECT statement equivalent.)

'''Example 6''': Table/relvar creation

 create("myThings", dataDictionaryTable)
* Note: SmeQl does not pre-define table features, such as column types, in order to facilitate domain independence and improve compatibility with existing RDBMS vendors.

'''Example 7:''' Transitive closure or recursion - "all paths" of a digraph

'''Example 8:''' Natural equi-join

SMEQL: 

(No current natural join. Predefined "join dictionary" recommended instead. See TqlChainedJoin.)

'''Example 9:''' Equi-join

SMEQL:
 J = join(red, blue, a.x = b.y)
 Calc(J, [foo, bar])
* ''Where do 'a' and 'b' come from?''
* See TqlPrefix. Basically "a" is the left table and "b" the right table.

'''Example 10:''' Equi-join with same-named key

SMEQL
 J = join(red, blue, a.x = b.x)
 Calc(J, [foo, bar])

'''Example 11:''' Top 3 largest planets, use name if tie

SMEQL
  sized = orderBy(planets, [desc(diameter), name], sequence)
  filter(sized, sequence <= 3)

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See also ConceptualQueryExampleOfAdvantages
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CategoryQueryLanguage, CategorySpeculative