diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/func.sgml | 22 | ||||
| -rw-r--r-- | doc/src/sgml/ref/create_rule.sgml | 35 |
2 files changed, 40 insertions, 17 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 9e2c2458329..b5947e3b8a8 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -689,6 +689,14 @@ <entry>seconds past midnight (0-86399)</entry> </row> <row> + <entry>AM or A.M. or PM or P.M.</entry> + <entry>meridian indicator (upper case)</entry> + </row> + <row> + <entry>am or a.m. or pm or p.m.</entry> + <entry>meridian indicator (lower case)</entry> + </row> + <row> <entry>Y,YYY</entry> <entry>year (4 and more digits) with comma</entry> </row> @@ -709,6 +717,14 @@ <entry>last digit of year</entry> </row> <row> + <entry>BC or B.C. or AD or A.D.</entry> + <entry>year indicator (upper case)</entry> + </row> + <row> + <entry>bc or b.c. or ad or a.d.</entry> + <entry>year indicator (lower case)</entry> + </row> + <row> <entry>MONTH</entry> <entry>full upper case month name (9 chars)</entry> </row> @@ -794,7 +810,11 @@ </row> <row> <entry>RM</entry> - <entry>month in Roman Numerals (I-XII; I=JAN)</entry> + <entry>month in Roman Numerals (I-XII; I=JAN) - upper case</entry> + </row> + <row> + <entry>rn</entry> + <entry>month in Roman Numerals (I-XII; I=JAN) - lower case</entry> </row> </tbody> </tgroup> diff --git a/doc/src/sgml/ref/create_rule.sgml b/doc/src/sgml/ref/create_rule.sgml index 96ef1687f17..6ecbdf4f768 100644 --- a/doc/src/sgml/ref/create_rule.sgml +++ b/doc/src/sgml/ref/create_rule.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_rule.sgml,v 1.13 2000/04/07 17:37:24 momjian Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_rule.sgml,v 1.14 2000/04/07 19:17:30 momjian Exp $ Postgres documentation --> @@ -126,16 +126,17 @@ CREATE <para> The <productname>Postgres</productname> <firstterm>rule system</firstterm> allows one to define an - alternate action to be performed on updates, inserts, or deletions + alternate action to be performed on inserts, updates, or deletions from database tables or classes. Currently, rules are used to implement table views. </para> <para> The semantics of a rule is that at the time an individual instance is - accessed, updated, inserted or deleted, there is a current instance (for - retrieves, updates and deletes) and a new instance (for updates and - appends). If the <replaceable class="parameter">event</replaceable> + accessed, inserted, updated, or deleted, there is a current instance (for + selects, updates and deletes) and a new instance (for inserts and + updates). + If the <replaceable class="parameter">event</replaceable> specified in the ON clause and the <replaceable class="parameter">condition</replaceable> specified in the WHERE clause are true for the current instance, the @@ -162,8 +163,8 @@ CREATE <para> A caution about SQL rules is in order. If the same class name or instance variable appears in the - <replaceable class="parameter">event</replaceable>, the - <replaceable class="parameter">condition</replaceable> and the + <replaceable class="parameter">event</replaceable>, + <replaceable class="parameter">condition</replaceable> and <replaceable class="parameter">action</replaceable> parts of a rule, they are all considered different tuple variables. More accurately, <literal>new</literal> and <literal>current</literal> are the only tuple @@ -172,13 +173,13 @@ CREATE <programlisting> ON UPDATE TO emp.salary WHERE emp.name = "Joe" DO - UPDATE emp ( ... ) WHERE ... + UPDATE emp SET ... WHERE ... </programlisting> <programlisting> ON UPDATE TO emp-1.salary WHERE emp-2.name = "Joe" DO - UPDATE emp-3 ( ... ) WHERE ... + UPDATE emp-3 SET ... WHERE ... </programlisting> Each rule can have the optional tag INSTEAD. @@ -194,11 +195,12 @@ ON UPDATE TO emp-1.salary WHERE emp-2.name = "Joe" <literal>NOTHING</literal>. </para> <para> - It is very important to note that the rewrite rule system - will neither detect nor process circular rules. For example, though each + It is very important to note to avoid circular rules. + For example, though each of the following two rule definitions are accepted by <productname>Postgres</productname>, the - retrieve command will cause <productname>Postgres</productname> to crash: + select command will cause <productname>Postgres</productname> to + report an error because the query cycled too many times: <example> <title>Example of a circular rewrite rule combination.</title> @@ -216,8 +218,9 @@ CREATE RULE bad_rule_combination_2 AS SELECT TO emp; </programlisting> <para> - This attempt to retrieve from EMP will cause - <productname>Postgres</productname> to crash. + This attempt to select from EMP will cause + <productname>Postgres</productname> to issue an error + because the queries cycled too many times. <programlisting> SELECT * FROM emp; </programlisting></para> @@ -306,7 +309,7 @@ CREATE toyemp(name = char16, salary = int4); CREATE RULE example_4 AS ON SELECT TO toyemp DO INSTEAD - SELECT (emp.name, emp.salary) + SELECT emp.name, emp.salary FROM emp WHERE emp.dept = "toy"; </programlisting> @@ -317,7 +320,7 @@ CREATE RULE example_4 AS CREATE RULE example_5 AS ON INERT TO emp WHERE new.salary > 5000 DO - UPDATE NEWSET salary = 5000; + UPDATE NEWSET SET salary = 5000; </programlisting> </para> </refsect1> |