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Merge branch 'cassandra-3.5' into trunk

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Sylvain Lebresne 2016-03-17 10:22:10 +01:00
parent 7a9b8ca4e2 d526ad79d7
commit 3508cd1af3
1 changed files with 17 additions and 9 deletions
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26
doc/cql3/CQL.textile
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@ -869,17 +869,21 @@ bc(syntax)..
| <identifier> '=' <identifier> '+' <map-literal>
| <identifier> '[' <term> ']' '=' <term>
<condition> ::= <identifier> '=' <term>
| <identifier> '[' <term> ']' '=' <term>
<condition> ::= <identifier> <op> <term>
| <identifier> IN (<variable> | '(' ( <term> ( ',' <term> )* )? ')')
| <identifier> '[' <term> ']' <op> <term>
| <identifier> '[' <term> ']' IN <term>
<op> ::= '<' | '<=' | '=' | '!=' | '>=' | '>'
<where-clause> ::= <relation> ( AND <relation> )*
<relation> ::= <identifier> '=' <term>
| '(' <identifier> (',' <identifier>)* ')' '=' <term-tuple>
| <identifier> IN '(' ( <term> ( ',' <term>)* )? ')'
| <identifier> IN '?'
| <identifier> IN <variable>
| '(' <identifier> (',' <identifier>)* ')' IN '(' ( <term-tuple> ( ',' <term-tuple>)* )? ')'
| '(' <identifier> (',' <identifier>)* ')' IN '?'
| '(' <identifier> (',' <identifier>)* ')' IN <variable>
<option> ::= TIMESTAMP <integer>
| TTL <integer>
@ -897,7 +901,7 @@ UPDATE UserActions SET total = total + 2 WHERE user = B70DE1D0-9908-4AE3-BE34-55
p.
The @UPDATE@ statement writes one or more columns for a given row in a table. The @<where-clause>@ is used to select the row to update and must include all columns composing the @PRIMARY KEY@. Other columns values are specified through @<assignment>@ after the @SET@ keyword.
Note that unlike in SQL, @UPDATE@ does not check the prior existence of the row by default: the row is created if none existed before, and updated otherwise. Furthermore, there are no means to know whether a creation or update occurred.
Note that unlike in SQL, @UPDATE@ does not check the prior existence of the row by default (except through the use of @<condition>@, see below): the row is created if none existed before, and updated otherwise. Furthermore, there are no means to know whether a creation or update occurred.
It is however possible to use the conditions on some columns through @IF@, in which case the row will not be updated unless the conditions are met. But, please note that using @IF@ conditions will incur a non-negligible performance cost (internally, Paxos will be used) so this should be used sparingly.
@ -932,13 +936,17 @@ bc(syntax)..
<relation> ::= <identifier> <op> <term>
| '(' <identifier> (',' <identifier>)* ')' <op> <term-tuple>
| <identifier> IN '(' ( <term> ( ',' <term>)* )? ')'
| <identifier> IN '?'
| <identifier> IN <variable>
| '(' <identifier> (',' <identifier>)* ')' IN '(' ( <term-tuple> ( ',' <term-tuple>)* )? ')'
| '(' <identifier> (',' <identifier>)* ')' IN '?'
| '(' <identifier> (',' <identifier>)* ')' IN <variable>
<op> ::= '=' | '<' | '>' | '<=' | '>='
<condition> ::= <identifier> '=' <term>
| <identifier> '[' <term> ']' '=' <term>
<condition> ::= <identifier> (<op> | '!=') <term>
| <identifier> IN (<variable> | '(' ( <term> ( ',' <term> )* )? ')')
| <identifier> '[' <term> ']' (<op> | '!=') <term>
| <identifier> '[' <term> ']' IN <term>
p.
__Sample:__