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PostgreSQL documentation

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</para>

<refsect3 id="APP-PSQL-patterns">

<title id="APP-PSQL-patterns-title">Patterns</title>

<indexterm>

<primary>patterns</primary>

<secondary>in psql and pg_dump</secondary>

</indexterm>

<para>

The various <literal>\d</> commands accept a <replaceable

class="parameter">pattern</replaceable> parameter to specify the

object name(s) to be displayed. <literal>*</> means <quote>any

sequence of characters</> and <literal>?</> means <quote>any single

character</>. (This notation is comparable to Unix shell file name

patterns.) Advanced users can also use regular-expression

notations such as character classes, for example <literal>[0-9]</>

to match <quote>any digit</>. To make any of these

pattern-matching characters be interpreted literally, surround it

with double quotes.

object name(s) to be displayed. In the simplest case, a pattern

is just the exact name of the object. The characters within a

pattern are normally folded to lower case, just as in SQL names;

for example, <literal>\dt FOO</> will display the table named

<literal>foo</>. As in SQL names, placing double quotes around

a pattern stops folding to lower case. Should you need to include

an actual double quote character in a pattern, write it as a pair

of double quotes within a double-quote sequence; again this is in

accord with the rules for SQL quoted identifiers. For example,

<literal>\dt "FOO""BAR"</> will display the table named

<literal>FOO"BAR</> (not <literal>foo"bar</>). Unlike the normal

rules for SQL names, you can put double quotes around just part

of a pattern, for instance <literal>\dt FOO"FOO"BAR</> will display

the table named <literal>fooFOObar</>.

</para>

<para>

Within a pattern, <literal>*</> matches any sequence of characters

(including no characters) and <literal>?</> matches any single character.

(This notation is comparable to Unix shell file name patterns.)

For example, <literal>\dt int*</> displays all tables whose names

begin with <literal>int</>. But within double quotes, <literal>*</>

and <literal>?</> lose these special meanings and are just matched

literally.

</para>

<para>

A pattern that containsan (unquoted) dot is interpreted as a schema

A pattern that containsa dot (<literal>.</>) is interpreted as a schema

name pattern followed by an object name pattern. For example,

<literal>\dt foo*.bar*</> displays all tablesin schemaswhose name

starts with <literal>foo</>andwhosetable name

starts with <literal>bar</>.If no dot appears, then the pattern

<literal>\dt foo*.bar*</> displays all tables whose table name

starts with <literal>bar</>that are in schemaswhoseschema name

starts with <literal>foo</>.When no dot appears, then the pattern

matches only objects that are visible in the current schema search path.

Again, a dot within double quotes loses its special meaning and is matched

literally.

</para>

<para>

Advanced users can use regular-expression notations such as character

classes, for example <literal>[0-9]</> to match any digit. All regular

expression special characters work as specified in

<xref linkend="functions-posix-regexp">, except for <literal>.</> which

is taken as a separator as mentioned above, <literal>*</> which is

translated to the regular-expression notation <literal>.*</>, and

<literal>?</> which is translated to <literal>.</>. You can emulate

these pattern characters at need by writing

<literal>?</> for <literal>.</>,

<literal>(<replaceable class="parameter">R</replaceable>+|)</literal> for

<literal><replaceable class="parameter">R</replaceable>*</literal>, or

<literal>(<replaceable class="parameter">R</replaceable>|)</literal> for

<literal><replaceable class="parameter">R</replaceable>?</literal>.

Remember that the pattern must match the whole name, unlike the usual

interpretation of regular expressions; write <literal>*</> at the beginning

and/or end if you don't wish the pattern to be anchored.

Note that within double quotes, all regular expression special characters

lose their special meanings and are matched literally. Also, the regular

expression special characters are matched literally in operator name

patterns (i.e., the argument of <literal>\do</>).

</para>

<para>

Whenever the <replaceable class="parameter">pattern</replaceable> parameter

is omitted completely, the <literal>\d</> commands display all objects

that are visible in the current schema search path. To see all objects

in the database, use the pattern <literal>*.*</>.

that are visible in the current schema search path &mdash; this is

equivalent to using the pattern <literal>*</>.

To see all objects in the database, use the pattern <literal>*.*</>.

</para>

</refsect3>

</refsect2>

<refsect2>