database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-12-18 05:01:01 +03:00
Code Activity

A few minor psql enhancements

Browse Source 
Initdb help correction
Changed end/abort to commit/rollback and changed related notices
Commented out way old printing functions in libpq
Fixed a typo in alter table / alter column
This commit is contained in:
Peter Eisentraut
2000-01-29 16:58:54 +00:00
parent 7e7416bd4e
commit 2b84cbb60f
49 changed files with 821 additions and 870 deletions
Download Patch File Download Diff File Expand all files Collapse all files

171
doc/src/sgml/ref/alter_table.sgml
View File

@@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.9 2000/01/09 17:35:27 momjian Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.10 2000/01/29 16:58:27 petere Exp $
Postgres documentation
-->
@@ -23,11 +23,14 @@ Postgres documentation
<date>1999-07-20</date>
</refsynopsisdivinfo>
<synopsis>
ALTER TABLE <replaceable class="PARAMETER">table</replaceable>
[ * ] ADD [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> <replaceable
ALTER TABLE <replaceable class="PARAMETER">table</replaceable> [ * ]
ADD [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> <replaceable
class="PARAMETER">type</replaceable>
ALTER TABLE <replaceable class="PARAMETER">table</replaceable>
[ * ] RENAME [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> TO <replaceable
ALTER TABLE <replaceable class="PARAMETER">table</replaceable> [ * ]
ALTER [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> { SET DEFAULT <replaceable
class="PARAMETER">value</replaceable> | DROP DEFAULT }
ALTER TABLE <replaceable class="PARAMETER">table</replaceable> [ * ]
RENAME [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> TO <replaceable
class="PARAMETER">newcolumn</replaceable>
ALTER TABLE <replaceable class="PARAMETER">table</replaceable>
RENAME TO <replaceable class="PARAMETER">newtable</replaceable>
@@ -82,7 +85,7 @@ ALTER TABLE <replaceable class="PARAMETER">table</replaceable>
<term><replaceable class="PARAMETER"> newtable </replaceable></term>
<listitem>
<para>
New name for an existing column.
New name for the table.
</para>
</listitem>
</varlistentry>
@@ -101,9 +104,7 @@ ALTER TABLE <replaceable class="PARAMETER">table</replaceable>
<variablelist>
<varlistentry>
<term><computeroutput>
ALTER
</computeroutput></term>
<term><computeroutput>ALTER</computeroutput></term>
<listitem>
<para>
Message returned from column or table renaming.
@@ -112,20 +113,7 @@ ALTER
</varlistentry>
<varlistentry>
<term><computeroutput>
NEW
</computeroutput></term>
<listitem>
<para>
Message returned from column addition.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><computeroutput>
ERROR
</computeroutput></term>
<term><computeroutput>ERROR</computeroutput></term>
<listitem>
<para>
Message returned if table or column is not available.
@@ -146,9 +134,12 @@ ERROR
</title>
<para>
<command>ALTER TABLE</command> changes the definition of an existing table.
The new columns and their types are specified in the same style
and with the the same restrictions as in <command>CREATE TABLE</command>.
The RENAME clause causes the name of a table or column
The <literal>ADD COLUMN</literal> form adds a new column to the table
using the same syntax as <xref linkend="SQL-CREATETABLE"
endterm="SQL-CREATETABLE-title">. The <literal>ALTER COLUMN</literal> form
allows you to set or remove the default for the column. Note that defaults
only apply to newly inserted rows.
The <literal>RENAME</literal> clause causes the name of a table or column
to change without changing any of the data contained in
the affected table. Thus, the table or column will
remain of the same type and size after this command is
@@ -189,13 +180,12 @@ SELECT <replaceable>NewColumn</replaceable> FROM <replaceable>SuperClass</replac
</para>
<para>
For efficiency reasons, default values for added attributes are
not placed in existing instances of a class.
That is, existing instances will have NULL values in the new
attributes. If non-NULL values are desired, a subsequent
<command>UPDATE</command> query
(<xref linkend="sql-update-title" endterm="sql-update-title">)
should be run.
In the current implementation, default and constraint clauses for the
new column will be ignored. You can use the <literal>SET DEFAULT</literal>
form of <command>ALTER TABLE</command> to set the default later.
(You will also have to update the already existing rows to the
new default value, using <xref linkend="sql-update-title"
endterm="sql-update-title">.)
</para>
<para>
@@ -248,87 +238,38 @@ ALTER TABLE distributors RENAME TO suppliers;
<refsect2info>
<date>1998-04-15</date>
</refsect2info>
<title>
SQL92
</title>
<para>
<command>ALTER TABLE/RENAME</command>
is a <productname>Postgres</productname> language extension.
</para>
<title>SQL92</title>
<para>
The <literal>ADD COLUMN</literal> form is compliant with the exception that
it does not support defaults and constraints, as explained above.
The <literal>ALTER COLUMN</literal> form is in full compliance.
</para>
<para>
SQL92 specifies some additional capabilities for <command>ALTER TABLE</command>
statement which are not yet directly supported by
<productname>Postgres</productname>:
</para>
<para>
SQL92 specifies some additional capabilities for <command>ALTER TABLE</command>
statement which are not yet directly supported by <productname>PostgreSQL</productname>:
<variablelist>
<varlistentry>
<term>
<synopsis>
ALTER TABLE <replaceable class="PARAMETER">table</replaceable> ALTER [
COLUMN ] <replaceable class="PARAMETER">column</replaceable>
SET DEFAULT <replaceable class="PARAMETER">default</replaceable>
ALTER TABLE <replaceable class="PARAMETER">table</replaceable> ALTER [
COLUMN ] <replaceable class="PARAMETER">column</replaceable>
ADD [ CONSTRAINT <replaceable class="PARAMETER">>constrain</replaceable>> ] <replaceable
class="PARAMETER">table-constraint</replaceable>
<variablelist>
<varlistentry>
<term>
<synopsis>
ALTER TABLE <replaceable class="PARAMETER">table</replaceable> ADD <replaceable class="PARAMETER">table constraint definition</replaceable>
ALTER TABLE <replaceable class="PARAMETER">table</replaceable> DROP CONSTRAINT <replaceable class="PARAMETER">constraint</replaceable> { RESTRICT | CASCADE }
</synopsis>
</term>
<listitem>
<para>
Puts the default value or constraint specified into the
definition of column in the table.
See <command>CREATE TABLE</command> for the
syntax of the default and table-constraint clauses.
If a default clause already exists, it will be replaced by
the new definition. If any constraints on this column already
exist, they will be retained using a boolean AND with the new
constraint.
Adds or removes a table constraint (such as a check constraint,
unique constraint, or foreign key constraint). To create
or remove a unique constraint, create or drop a unique index,
respectively (see <xref linkend="SQL-CREATEINDEX" endterm="SQL-CREATEINDEX-title">).
To change other kinds of constraints you need to recreate
and reload the table, using other parameters to the
<xref linkend="SQL-CREATETABLE" endterm="SQL-CREATETABLE-title">
command.
</para>
<para>
Currently, to set new default constraints on an existing column
the table must be recreated and reloaded:
<programlisting>
CREATE TABLE temp AS SELECT * FROM distributors;
DROP TABLE distributors;
CREATE TABLE distributors (
did DECIMAL(3) DEFAULT 1,
name VARCHAR(40) NOT NULL,
city VARCHAR(30)
);
INSERT INTO distributors SELECT * FROM temp;
DROP TABLE temp;
</programlisting>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<synopsis>
ALTER TABLE <replaceable class="PARAMETER">table</replaceable>
DROP DEFAULT <replaceable class="PARAMETER">default</replaceable>
ALTER TABLE <replaceable class="PARAMETER">table</replaceable>
DROP CONSTRAINT <replaceable class="PARAMETER">constraint</replaceable> { RESTRICT | CASCADE }
</synopsis>
</term>
<listitem>
<para>
Removes the default value specified by default or the rule
specified by constraint from the definition of a table.
If RESTRICT is specified only a constraint with no dependent
constraints can be destroyed.
If CASCADE is specified, Any constraints that are dependent on
this constraint are also dropped.
</para>
<para>
Currently, to remove a default value or constraints on an
existing column the table must be recreated and reloaded:
For example, to drop any constraints on a table <literal>distributors</literal>:
<programlisting>
CREATE TABLE temp AS SELECT * FROM distributors;
DROP TABLE distributors;
@@ -342,23 +283,14 @@ DROP TABLE temp;
<varlistentry>
<term>
<synopsis>
ALTER TABLE <replaceable class="PARAMETER">table</replaceable>
DROP [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> { RESTRICT | CASCADE }
ALTER TABLE <replaceable class="PARAMETER">table</replaceable> DROP [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> { RESTRICT | CASCADE }
</synopsis>
</term>
<listitem>
<para>
Removes a column from a table.
If RESTRICT is specified only a column with no dependent
objects can be destroyed.
If CASCADE is specified, all objects that are dependent on
this column are also dropped.
</para>
<para>
Currently, to remove an existing column the table must be
recreated and reloaded:
<programlisting>
CREATE TABLE temp AS SELECT did, city FROM distributors;
DROP TABLE distributors;
@@ -373,6 +305,13 @@ DROP TABLE temp;
</listitem>
</varlistentry>
</variablelist>
</para>
<para>
The clauses to rename columns and tables are <productname>PostgreSQL</productname>
extensions. SQL92 does not provide for them.
</para>
</refsect2>
</refsect1>
</refentry>