From: Tom Lane Date: Wed, 5 Nov 2003 00:05:32 +0000 (+0000) Subject: Minor copy-editing. X-Git-Tag: REL8_0_0BETA1~1754 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e560dd3537f656e45b8101795181efe2819fffe1;p=postgresql Minor copy-editing. --- diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml index e224d3c513..627f25096b 100644 --- a/doc/src/sgml/ddl.sgml +++ b/doc/src/sgml/ddl.sgml @@ -1,4 +1,4 @@ - + Data Definition @@ -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 . + such as views, functions, and triggers. @@ -522,7 +521,7 @@ CREATE TABLE products ( 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 NULL constraint is not defined in the SQL standard and should not be used in portable applications. (It was only added to PostgreSQL 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 @@ -820,7 +819,7 @@ CREATE TABLE orders ( ); 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. @@ -1094,9 +1093,10 @@ WHERE c.altitude > 500 and c.tableoid = p.oid; Deprecated In previous versions of PostgreSQL, 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 * 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 + * to the table name. For example SELECT * from cities*; @@ -1270,6 +1270,12 @@ ALTER TABLE products ALTER COLUMN product_no SET NOT NULL; ALTER TABLE products DROP CONSTRAINT some_name; + (If you are dealing with a generated constraint name like $2, + don't forget that you'll need to double-quote it to make it a valid + identifier.) + + + This works the same for all constraint types except not-null constraints. To drop a not null constraint use @@ -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 CREATE privilege on the schema needs to be granted. Note that by default, everyone - has the CREATE privilege on the schema - public. This allows all users that manage to - connect to a given database to create objects there. If you do + has CREATE and USAGE privileges on + the schema + public. This allows all users that are able to + connect to a given database to create objects in its + public schema. If you do not want to allow that, you can revoke that privilege: REVOKE CREATE ON SCHEMA public FROM PUBLIC; @@ -1905,6 +1913,11 @@ REVOKE CREATE ON SCHEMA public FROM PUBLIC; + + + Detailed information on + these topics appears in . +