SQL grammar currently supported by QueryViz.com (Jan 2016) 
 
 
Q ::=
SELECT
C {[, C] | *} 
query/select clause
 
FROM
S [, S] 
 
from clause
 
[WHERE

[GROUP by

 HAVING

P]
C ([, C] )
 
where clause
group by clause
 
C ::=
[T.] A
column
 
S ::=
T [AS T]
source
 
P ::=
P AND P
predicate /conjunction
|
C O C
 
join
|
C O V
 
selection
|
[NOT] EXISTS (Q)
 
existential
|
C [NOT] IN (Q)
 
membership
|
C O {ALL|ANY (Q)} 
 
quantified
 
O ::=
< | <= | = | >= | > | <>
operator
 
T ::=
 
table identifier
 
A ::=
 

attribute identifier

 
V ::=
 
string or numerical value