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Make bit and bit varying types reject too long input. (They already tried

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to do that, but inconsistently.)  Make bit type reject too short input,
too, per SQL.  Since it no longer zero pads, 'zpbit*' has been renamed to
'bit*' in the source, hence initdb.
This commit is contained in:
Peter Eisentraut
2001-05-22 16:37:17 +00:00
parent c84c3d8fea
commit efcecd9eca
14 changed files with 203 additions and 253 deletions
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50
doc/src/sgml/datatype.sgml
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@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.54 2001/05/21 16:54:45 petere Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.55 2001/05/22 16:37:15 petere Exp $
-->
<chapter id="datatype">
@ -2276,30 +2276,52 @@ SELECT * FROM test1 WHERE a;
Bit strings are strings of 1's and 0's. They can be used to store
or visualize bit masks. There are two SQL bit types:
<type>BIT(<replaceable>x</replaceable>)</type> and <type>BIT
VARYING(<replaceable>x</replaceable>)</type>; the
<replaceable>x</replaceable> specifies the maximum length.
<type>BIT</type> type data is automatically padded with 0's on the
right to the maximum length, <type>BIT VARYING</type> is of
variable length. <type>BIT</type> without length is equivalent
to <literal>BIT(1)</literal>, <type>BIT VARYING</type> means
unlimited length. Input data that is longer than the allowed
length will be truncated. Refer to <xref
VARYING(<replaceable>x</replaceable>)</type>; where
<replaceable>x</replaceable> is a positive integer.
</para>
<para>
<type>BIT</type> type data must match the length
<replaceable>x</replaceable> exactly; it is an error to attempt to
store shorter or longer bit strings. <type>BIT VARYING</type> is
of variable length up to the maximum length
<replaceable>x</replaceable>; longer strings will be rejected.
<type>BIT</type> without length is equivalent to
<literal>BIT(1)</literal>, <type>BIT VARYING</type> without length
specification means unlimited length.
</para>
<note>
<para>
Prior to PostgreSQL 7.2, <type>BIT</type> type data was
zero-padded on the right. This was changed to comply with the
SQL standard. To implement zero-padded bit strings, a
combination of the concatenation operator and the
<function>substring</function> function can be used.
</para>
</note>
<para>
Refer to <xref
linkend="sql-syntax-bit-strings"> for information about the syntax
of bit string constants. Bit-logical operators and string
manipulation functions are available; see <xref
linkend="functions">.
</para>
<informalexample>
<para>
Some examples:
<example>
<title>Using the bit string types</title>
<programlisting>
CREATE TABLE test (a BIT(3), b BIT VARYING(5));
INSERT INTO test VALUES (B'101', B'00');
INSERT INTO test VALUES (B'10', B'101');
<computeroutput>
ERROR: bit string length does not match type bit(3)
</computeroutput>
SELECT SUBSTRING(b FROM 1 FOR 2) FROM test;
</programlisting>
</para>
</informalexample>
</example>
</sect1>