40.6. Rules and Command Status

40.6. Rules and Command Status
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+ The PostgreSQL server returns a command + status string, such as INSERT 149592 1, for each + command it receives. This is simple enough when there are no rules + involved, but what happens when the query is rewritten by rules? +

+ Rules affect the command status as follows: + +

+ If there is no unconditional INSTEAD rule for the query, then + the originally given query will be executed, and its command + status will be returned as usual. (But note that if there were + any conditional INSTEAD rules, the negation of their qualifications + will have been added to the original query. This might reduce the + number of rows it processes, and if so the reported status will + be affected.) +
+ If there is any unconditional INSTEAD rule for the query, then + the original query will not be executed at all. In this case, + the server will return the command status for the last query + that was inserted by an INSTEAD rule (conditional or + unconditional) and is of the same command type + (INSERT, UPDATE, or + DELETE) as the original query. If no query + meeting those requirements is added by any rule, then the + returned command status shows the original query type and + zeroes for the row-count and OID fields. +

+ The programmer can ensure that any desired INSTEAD rule is the one + that sets the command status in the second case, by giving it the + alphabetically last rule name among the active rules, so that it + gets applied last. +

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40.5. Rules and Privileges	Home	40.7. Rules Versus Triggers