.. _basic-anchor:

Query Structures
================

  SDQL query structures range from simple to as simple as possible.

parameters \@ conditions
------------------------

  The basic SDQL structure is a comma delimted list of parameters, an *@* sign, followed by an *and* delimited list of conditions.
  This can be thought of as 'what I want to see *at* the conditions under which I want to see it.'

  Here are a few examples:

    To request the date and points scored by the Colts in the 2016 season, use the SDQL:
       *date, points @ team=Colts and season=2016*

    To request the date, points, field goals made and field goals attempted for Bulls home games in 2015, use the SDQL:
       *date, points, field goals made, field goals attempted @ team=Bulls and site=home and season=2015*

    To get the date, team, starter, and the number of innings the starter went for all games in the 2017 MLB post season, use the SDQL:
       *date, team, starter, starter innings pitched @ season=2017 and playoffs=1*


  All of the sample `SDQL <http://SDQL.com>`_ queries above are *singletons.*
  Here are a few examples of query groupings (see :ref:`group-anchor`):

    To see the points and assists for each NBA team that played on June 12, 2017, use the SDQL:
       points, assists  @ team and date=20170612


    To see the date and points for each Bulls and each Lakers game in November 2016, along with average points over the whole month of November, use the SDQL:
      date, points, A(points) @ team and team in [Bulls,Lakers] and month=10 and season=2016

    *date* and *points* default to summative type *Column* which is a list of values; *A(points)* returns a single value.
    Because of these *mixed request fields*, this is called an *irregular* query.
    An irregular query is often useful as input to *subsequent queries* (see :ref:`subsequent-anchor`).

  If all of the parameters are *summatives* (see :ref:`summative-anchor`) then the query result is reduced to a singleton.

    To see the average points and average assists for each NBA team in 2016, use the SDQL:
      A(points), A(assists) @ team and season=2016

p \@ c | p' \@ c'
-----------------

  An SDQL query result is itself an SDQL data table and can be likewise queried  (see :ref:`subsequent-anchor`).

     To find MLB teams that had a season-long winning percentage of more than 60%, use the SDQL:
      A(W), R((team,season)) @ team and season | $1, $2 @ $1 >.60