A Simple Query
An SQL query consists of three pieces, or blocks: the select block, the
from block and the where block.
The select block tells the database which columns of data you want
it to return. You must separate each column name with a comma. For
example, if you wanted to find the celestial coordinates right
ascension (ra) and declination (dec) of an object, the select
block might read
select
ra, dec
The from block specifies which table (or tables) you want to search.
If you wanted to retrieve information from the specObj table, the from
block would read
from
specObj
The where block allows you to search for records with certain
characteristics. Your list of characteristics must be separated by the word
"AND". Suppose you wanted to limit your search to a patch
of sky with ra between 194 and 195 degrees and dec between 2 and 3
degrees. To search only this patch of sky, your where block would read
where
ra BETWEEN 194 AND 195 AND
dec BETWEEN 2 AND 3
The database will return only those records that have an ra between
194 and 195 and a dec between 2 and 3.
This query is shown in the query window below. Click Submit to send the
query to the database. When you see the results, scroll through them to
verify that all records have ra between 194 and 195 and dec between 2 and 3.
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