u added docs for sphinx

# Minimal makefile for Sphinx documentation

#

# You can set these variables from the command line, and also

# from the environment for the first two.

SPHINXOPTS    ?=

SPHINXBUILD   ?= sphinx-build

SOURCEDIR     = source

BUILDDIR      = build

# Put it first so that "make" without argument is like "make help".

help:

	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)

.PHONY: help Makefile

# Catch-all target: route all unknown targets to Sphinx using the new

# "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).

%: Makefile

	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)

docs contains documentation produced by sphinx

@ECHO OFF

pushd %~dp0

REM Command file for Sphinx documentation

if "%SPHINXBUILD%" == "" (

	set SPHINXBUILD=sphinx-build

)

set SOURCEDIR=source

set BUILDDIR=build

if "%1" == "" goto help

%SPHINXBUILD% >NUL 2>NUL

if errorlevel 9009 (

	echo.

	echo.The 'sphinx-build' command was not found. Make sure you have Sphinx

	echo.installed, then set the SPHINXBUILD environment variable to point

	echo.to the full path of the 'sphinx-build' executable. Alternatively you

	echo.may add the Sphinx directory to PATH.

	echo.

	echo.If you don't have Sphinx installed, grab it from

	echo.https://www.sphinx-doc.org/

	exit /b 1

)

%SPHINXBUILD% -M %1 %SOURCEDIR% %BUILDDIR% %SPHINXOPTS% %O%

goto end

:help

%SPHINXBUILD% -M help %SOURCEDIR% %BUILDDIR% %SPHINXOPTS% %O%

:end

popd

ADQL Queries

============

A query is a string with format

   <DIRECTIVE> [expression [<DIRECTIVE> ....]]

Valid directives are 

SELECTION 

   set of data to be selected

HOW_MANY 

   elements to select

WHICH_FIELDS 

   fields to select

FROM 

   which table to be queried

WHERE 

   condition for elements selection 

Examples of query strings:

1. Download all the data: 

::

   `SELECT * FROM exo.EXO`

2. Download only the first 10 elements:  

::

   `SELECT TOP 10 * FROM exo.EXO`

3. Download only the first 10 elements with SMA in the range 0.9 to 1.1: 

::

   `SELECT TOP 10 * FROM exo.EXO WHERE SMA BETWEEN 0.9 AND 1.1`

4. The same but with a different expression

::

   `SELECT TOP 10 * FROM exo.EXO WHERE (0.9 <= SMA) AND (SMA <= 1.1)`

5. Download only the first 10 elements with SMA in the range 0.9 to 1.1 and CONTHAB>=0.5

::

   `SELECT TOP 10 * FROM exo.EXO WHERE SMA BETWEEN 0.9 AND 1.1 AND CONTHAB>=0.5`

6. Arithmetic calculations are allowed if needed for selection so to download the first 10 elements with SMA^1.5 > 0.87 

::

   `SELECT TOP 10 * FROM exo.EXO WHERE power(SMA,1.5)> 0.87` 

7. returns just columns SMA and CONTHAB from previous example:

::

   `SELECT TOP 10 SMA,CONTHAB FROM exo.EXO WHERE power(SMA,1.5)> 0.87` 

Note that a query string is not sensitive to uppercase or lowercase.

For other details see: 

   - http://www.g-vo.org/tutorials/gaia-mock-tap.pdf

   - http://www.ivoa.net/documents/REC/ADQL/ADQL-20081030.pdf

   - http://www.ivoa.net/documents/

An inline reminder of how to form query strings can be recalled by:

   >>> atap.EXPLAIN()