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author | Tom Lane <tgl@sss.pgh.pa.us> | 2003-11-05 00:05:32 +0000 |
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committer | Tom Lane <tgl@sss.pgh.pa.us> | 2003-11-05 00:05:32 +0000 |
commit | e560dd3537f656e45b8101795181efe2819fffe1 (patch) | |
tree | c61e3799b61c5b92925ceec5274fe54c91f1cdd6 | |
parent | 1a61554b59bce00c80d7d3318057d45e14ce8c2b (diff) | |
download | postgresql-e560dd3537f656e45b8101795181efe2819fffe1.tar.gz postgresql-e560dd3537f656e45b8101795181efe2819fffe1.zip |
Minor copy-editing.
-rw-r--r-- | doc/src/sgml/ddl.sgml | 37 |
1 files changed, 25 insertions, 12 deletions
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml index e224d3c5139..627f25096b4 100644 --- a/doc/src/sgml/ddl.sgml +++ b/doc/src/sgml/ddl.sgml @@ -1,4 +1,4 @@ -<!-- $Header: /cvsroot/pgsql/doc/src/sgml/ddl.sgml,v 1.22 2003/11/04 09:55:38 petere Exp $ --> +<!-- $Header: /cvsroot/pgsql/doc/src/sgml/ddl.sgml,v 1.23 2003/11/05 00:05:32 tgl Exp $ --> <chapter id="ddl"> <title>Data Definition</title> @@ -12,8 +12,7 @@ Subsequently, we discuss how tables can be organized into schemas, and how privileges can be assigned to tables. Finally, we will briefly look at other features that affect the data storage, - such as views, functions, and triggers. Detailed information on - these topics is found in <xref linkend="server-programming">. + such as views, functions, and triggers. </para> <sect1 id="ddl-basics"> @@ -522,7 +521,7 @@ CREATE TABLE products ( <para> It should be noted that a check constraint is satisfied if the check expression evaluates to true or the null value. Since most - expressions will evaluate to the null value if one operand is null + expressions will evaluate to the null value if one operand is null, they will not prevent null values in the constrained columns. To ensure that a column does not contain null values, the not-null constraint described in the next section should be used. @@ -586,7 +585,7 @@ CREATE TABLE products ( The <literal>NULL</literal> constraint is not defined in the SQL standard and should not be used in portable applications. (It was only added to <productname>PostgreSQL</productname> to be - compatible with other database systems.) Some users, however, + compatible with some other database systems.) Some users, however, like it because it makes it easy to toggle the constraint in a script file. For example, you could start with <programlisting> @@ -820,7 +819,7 @@ CREATE TABLE orders ( ); </programlisting> because in absence of a column list the primary key of the - referenced table is used as referenced column. + referenced table is used as the referenced column. </para> <para> @@ -1094,9 +1093,10 @@ WHERE c.altitude > 500 and c.tableoid = p.oid; <title>Deprecated</title> <para> In previous versions of <productname>PostgreSQL</productname>, the - default was not to get access to child tables. This was found to - be error prone and is also in violation of the SQL99 standard. Under the old - syntax, to get the sub-tables you append <literal>*</literal> to the table name. + default behavior was not to include child tables in queries. This was + found to be error prone and is also in violation of the SQL99 + standard. Under the old syntax, to get the sub-tables you append + <literal>*</literal> to the table name. For example <programlisting> SELECT * from cities*; @@ -1270,6 +1270,12 @@ ALTER TABLE products ALTER COLUMN product_no SET NOT NULL; <programlisting> ALTER TABLE products DROP CONSTRAINT some_name; </programlisting> + (If you are dealing with a generated constraint name like <literal>$2</>, + don't forget that you'll need to double-quote it to make it a valid + identifier.) + </para> + + <para> This works the same for all constraint types except not-null constraints. To drop a not null constraint use <programlisting> @@ -1739,9 +1745,11 @@ SELECT 3 OPERATOR(pg_catalog.+) 4; A user can also be allowed to create objects in someone else's schema. To allow that, the <literal>CREATE</literal> privilege on the schema needs to be granted. Note that by default, everyone - has the <literal>CREATE</literal> privilege on the schema - <literal>public</literal>. This allows all users that manage to - connect to a given database to create objects there. If you do + has <literal>CREATE</literal> and <literal>USAGE</literal> privileges on + the schema + <literal>public</literal>. This allows all users that are able to + connect to a given database to create objects in its + <literal>public</literal> schema. If you do not want to allow that, you can revoke that privilege: <programlisting> REVOKE CREATE ON SCHEMA public FROM PUBLIC; @@ -1905,6 +1913,11 @@ REVOKE CREATE ON SCHEMA public FROM PUBLIC; </para> </listitem> </itemizedlist> + + <para> + Detailed information on + these topics appears in <xref linkend="server-programming">. + </para> </sect1> <sect1 id="ddl-depend"> |