php-doc-en/functions/mysql.xml

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<reference id="ref.mysql">
<title>MySQL functions</title>
<titleabbrev>MySQL</titleabbrev>
<partintro>
<simpara>
These functions allow you to access MySQL database servers. In
order to have these functions available, you must compile php
with mysql support by using the
<option role="configure">--with-mysql</option> option. If you
use this option without specifying the path to mysql, php will
use the built-in mysql client libraries. Users who run other
applications that use mysql (for example, running php3 and php4
as concurrent apache modules, or auth-mysql) should always
specify the path to mysql:
<option role="configure">--with-mysql=/path/to/mysql</option>.
This will force php to use the client libraries installed by
mysql, avoiding any conflicts.
</simpara>
<simpara>
More information about MySQL can be found at <ulink
url="&url.mysql;">&url.mysql;</ulink>.
</simpara>
<simpara>
Documentation for MySQL can be found at <ulink
url="&url.mysql.docs;">&url.mysql.docs;</ulink>.
</simpara>
</partintro>
<refentry id="function.mysql-affected-rows">
<refnamediv>
<refname>mysql_affected_rows</refname>
<refpurpose>Get number of affected rows in previous MySQL
operation</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_affected_rows</function></funcdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_affected_rows</function> returns the number of
rows affected by the last INSERT, UPDATE or DELETE query on the
server associated with the specified link identifier. If the
link identifier isn't specified, the last opened link is assumed.
</para>
<para>
If the last query was a DELETE query with no WHERE clause, all
of the records will have been deleted from the table but this
function will return zero.
</para>
<para>
This command is not effective for SELECT statements, only on
statements which modify records. To retrieve the number of rows
returned from a SELECT, use <function>mysql_num_rows</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-change-user">
<refnamediv>
<refname>mysql_change_user</refname>
<refpurpose>
Change logged in user of the active connection
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_change_user</function></funcdef>
<paramdef>string <parameter>user</parameter></paramdef>
<paramdef>string <parameter>password</parameter></paramdef>
<paramdef>string
<parameter>
<optional>database</optional>
</parameter>
</paramdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_change_user</function> changes the logged in user
of the current active connection, or the connection given by the
optional parameter link_identifier. If a database is
specified, this will default or current database after the user
has been changed. If the new user and password authorization fails,
the current connected user stays active.</para>
<note><para>This function was introduced in PHP 3.0.13 and
requires MySQL 3.23.3 or higher.
</para></note>
</refsect1>
</refentry>
<refentry id="function.mysql-close">
<refnamediv>
<refname>mysql_close</refname>
<refpurpose>Close MySQL connection</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_close</function></funcdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns: true on success, false on error.
</para>
<para> <function>mysql_close</function> closes the connection to
the MySQL server that's associated with the specified link
identifier. If <parameter>link_identifier</parameter> isn't
specified, the last opened link is used.
</para>
<para>
Using <function>mysql_close</function> isn't usually necessary,
as non-persistent open links are automatically closed at the end
of the script's execution.
</para>
<note>
<para>
<function>mysql_close</function> will not close persistent links
created by <function>mysql_pconnect</function>.
</para>
</note>
<example>
<title>MySQL close example</title>
<programlisting role="php">
&lt;?php
$link = mysql_connect ("kraemer", "marliesle", "secret")
or die ("Could not connect");
print ("Connected successfully");
mysql_close ($link);
?>
</programlisting>
</example>
<para>
See also: <function>mysql_connect</function>, and
<function>mysql_pconnect</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-connect">
<refnamediv>
<refname>mysql_connect</refname>
<refpurpose>Open a connection to a MySQL Server</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_connect</function></funcdef>
<paramdef>string
<parameter>
<optional>hostname
<optional>:port</optional>
<optional>:/path/to/socket</optional>
</optional>
</parameter>
</paramdef>
<paramdef>string
<parameter>
<optional>username</optional>
</parameter>
</paramdef>
<paramdef>string
<parameter>
<optional>password</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns a positive MySQL link identifier on success, or an error
message on failure.
</para>
<para>
<function>mysql_connect</function> establishes a connection
to a MySQL server. The following defaults are assumed for
missing optional parameters: <parameter>host:port</parameter> =
'localhost:3306', <parameter>username</parameter> = name of the
user that owns the server process and
<parameter>password</parameter> = empty password.
</para>
<para>
The hostname string can also include a port
number. eg. &quot;hostname:port&quot; or a path to a socket
eg. &quot;:/path/to/socket&quot; for the localhost.
<note>
<para>
Support for &quot;:port&quot; was added in PHP 3.0B4.
</para>
<para>
Support for &quot;:/path/to/socket&quot; was added in
PHP 3.0.10.
</para>
<para>
You can suppress the error message on failure by prepending '@'
to the function name.
</para>
</note>
</para>
<para>
If a second call is made to <function>mysql_connect</function>
with the same arguments, no new link will be established, but
instead, the link identifier of the already opened link will be
returned.
</para>
<para>
The link to the server will be closed as soon as the execution of
the script ends, unless it's closed earlier by explicitly calling
<function>mysql_close</function>.
</para>
<example>
<title>MySQL connect example</title>
<programlisting role="php">
&lt;?php
$link = mysql_connect ("kraemer", "marliesle", "secret")
or die ("Could not connect");
print ("Connected successfully");
mysql_close ($link);
?>
</programlisting>
</example>
<para> See also
<function>mysql_pconnect</function>, and
<function>mysql_close</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-create-db">
<refnamediv>
<refname>mysql_create_db</refname>
<refpurpose>Create a MySQL database</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_create_db</function></funcdef>
<paramdef>string <parameter>database name</parameter></paramdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_create_db</function> attempts to create a new
database on the server associated with the specified link
identifier.
</para>
<example>
<title>MySQL create database example</title>
<programlisting role="php">
&lt;?php
$link = mysql_pconnect ("kron", "jutta", "geheim")
or die ("Could not connect");
if (mysql_create_db ("my_db")) {
print ("Database created successfully\n");
} else {
printf ("Error creating database: %s\n", mysql_error ());
}
?>
</programlisting>
</example>
<para>
For downwards compatibility <function>mysql_createdb</function>
can also be used.
</para>
<para>
See also: <function>mysql_drop_db</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-data-seek">
<refnamediv>
<refname>mysql_data_seek</refname>
<refpurpose>Move internal result pointer</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_data_seek</function></funcdef>
<paramdef>int <parameter>result_identifier</parameter></paramdef>
<paramdef>int <parameter>row_number</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns: true on success, false on failure.
</para>
<para>
<function>mysql_data_seek</function> moves the internal row
pointer of the MySQL result associated with the specified result
identifier to point to the specified row number. The next call
to <function>mysql_fetch_row</function> would return that row.
</para>
<para>
<parameter>Row_number</parameter> starts at 0.
</para>
<example>
<title>MySQL data seek example</title>
<programlisting role="php">
&lt;?php
$link = mysql_pconnect ("kron", "jutta", "geheim")
or die ("Could not connect");
mysql_select_db ("samp_db")
or die ("Could not select database");
$query = "SELECT last_name, first_name FROM friends";
$result = mysql_query ($query)
or die ("Query failed");
# fetch rows in reverse order
for ($i = mysql_num_rows ($result) - 1; $i >=0; $i--) {
if (!mysql_data_seek ($result, $i)) {
printf ("Cannot seek to row %d\n", $i);
continue;
}
if(!($row = mysql_fetch_object ($result)))
continue;
printf ("%s %s&lt;BR>\n", $row->last_name, $row->first_name);
}
mysql_free_result ($result);
?>
</programlisting>
</example>
</refsect1>
</refentry>
<refentry id="function.mysql-db-name">
<refnamediv>
<refname>mysql_db_name</refname>
<refpurpose>Get result data</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_db_name</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
<paramdef>int <parameter>row</parameter></paramdef>
<paramdef>mixed
<parameter>
<optional>field</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_db_name</function> takes as its first parameter
the result pointer from a call to
<function>mysql_list_dbs</function>. The
<parameter>row</parameter> parameter is an index into the result
set.
</para>
<para>
If an error occurs, FALSE is returned. Use
<function>mysql_errno</function> and
<function>mysql_error</function> to determine the nature of the
error.
</para>
<example>
<title><function>Mysql_db_name</function> example</title>
<programlisting role="php">
&lt;?php
error_reporting(E_ALL);
mysql_connect('dbhost', 'username', 'password');
$db_list = mysql_list_dbs();
$i = 0;
$cnt = mysql_numrows($db_list);
while ($i < $cnt) {
echo mysql_db_name($db_list, $i) . "\n";
$i++;
}
?>
</programlisting>
</example>
<para>
For backward compatibility, <function>mysql_dbname</function> is
also accepted. This is deprecated, however.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-db-query">
<refnamediv>
<refname>mysql_db_query</refname>
<refpurpose>Send a MySQL query</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_db_query</function></funcdef>
<paramdef>string <parameter>database</parameter></paramdef>
<paramdef>string <parameter>query</parameter></paramdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns: A positive MySQL result identifier to the query result,
or false on error.
</para>
<para>
<function>mysql_db_query</function> selects a database and
executes a query on it. If the optional link identifier isn't
specified, the function will try to find an open link to the
MySQL server and if no such link is found it'll try to create one
as if <function>mysql_connect</function> was called with no
arguments
</para>
<para>
See also <function>mysql_connect</function>.
</para>
<para>
For downwards
compatibility <function>mysql</function> can also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-drop-db">
<refnamediv>
<refname>mysql_drop_db</refname>
<refpurpose>Drop (delete) a MySQL database</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_drop_db</function></funcdef>
<paramdef>string <parameter>database_name</parameter></paramdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns: true on success, false on failure.
</para>
<para>
<function>mysql_drop_db</function> attempts to drop (remove) an
entire database from the server associated with the specified
link identifier.
</para>
<para>
See also: <function>mysql_create_db</function>. For downward
compatibility <function>mysql_dropdb</function> can also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-errno">
<refnamediv>
<refname>mysql_errno</refname>
<refpurpose>Returns the numerical value of the error message from previous
MySQL operation</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_errno</function></funcdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns the error number from the last mySQL function, or
<literal>0</literal> (zero) if no error occurred.
</para>
<para>
Errors coming back from the mySQL database backend no longer
issue warnings. Instead, use <function>mysql_errno</function> to
retrieve the error code. Note that this function only returns the
error code from the most recently executed mySQL function (not
including <function>mysql_error</function> and
<function>mysql_errno</function>), so if you want to use it,
make sure you check the value before calling another mySQL
function.
<informalexample>
<programlisting role="php">
&lt;?php
mysql_connect("marliesle");
echo mysql_errno().": ".mysql_error()."&lt;BR>";
mysql_select_db("nonexistentdb");
echo mysql_errno().": ".mysql_error()."&lt;BR>";
$conn = mysql_query("SELECT * FROM nonexistenttable");
echo mysql_errno().": ".mysql_error()."&lt;BR>";
?>
</programlisting>
</informalexample>
</para>
<para>
See also: <function>mysql_error</function>
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-error">
<refnamediv>
<refname>mysql_error</refname>
<refpurpose>Returns the text of the error message from previous
MySQL operation</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>string <function>mysql_error</function></funcdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns the error text from the last mySQL function, or
<literal>''</literal> (the empty string) if no error occurred.
</para>
<para>
Errors coming back from the mySQL database backend no longer
issue warnings. Instead, use <function>mysql_error</function> to
retrieve the error text. Note that this function only returns the
error text from the most recently executed mySQL function (not
including <function>mysql_error</function> and
<function>mysql_errno</function>), so if you want to use it, make
sure you check the value before calling another mySQL function.
<informalexample>
<programlisting role="php">
&lt;?php
mysql_connect("marliesle");
echo mysql_errno().": ".mysql_error()."&lt;BR>";
mysql_select_db("nonexistentdb");
echo mysql_errno().": ".mysql_error()."&lt;BR>";
$conn = mysql_query("SELECT * FROM nonexistenttable");
echo mysql_errno().": ".mysql_error()."&lt;BR>";
?>
</programlisting>
</informalexample>
</para>
<para>
See also: <function>mysql_errno</function>
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-fetch-array">
<refnamediv>
<refname>mysql_fetch_array</refname>
<refpurpose>
Fetch a result row as an associative array
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>array <function>mysql_fetch_array</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
<paramdef>int
<parameter>
<optional>result_type</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns an array that corresponds to the fetched row, or false
if there are no more rows.</para>
<para>
<function>mysql_fetch_array</function> is an extended version of
<function>mysql_fetch_row</function>. In addition to storing the
data in the numeric indices of the result array, it also stores
the data in associative indices, using the field names as keys.
</para>
<para>
If two or more columns of the result have the same field names,
the last column will take precedence. To access the other column(s)
of the same name, you must the numeric index of the column or
make an alias for the column.
<informalexample>
<programlisting>
select t1.f1 as foo t2.f1 as bar from t1, t2
</programlisting>
</informalexample>
</para>
<para>
An important thing to note is that using
<function>mysql_fetch_array</function> is NOT significantly
slower than using <function>mysql_fetch_row</function>, while it
provides a significant added value.
</para>
<para>
The optional second argument <parameter>result_type</parameter>
in <function>mysql_fetch_array</function> is a constant and can
take the following values: MYSQL_ASSOC, MYSQL_NUM, and
MYSQL_BOTH. (This feature was added in PHP 3.0.7)
</para>
<para>
For further details, see also
<function>mysql_fetch_row</function>.
</para>
<example>
<title><function>Mysql_fetch_array</function></title>
<programlisting role="php">
&lt;?php
mysql_connect ($host, $user, $password);
$result = mysql_db_query ("database","select * from table");
while ($row = mysql_fetch_array ($result)) {
echo $row["user_id"];
echo $row["fullname"];
}
mysql_free_result ($result);
?>
</programlisting>
</example>
</refsect1>
</refentry>
<refentry id="function.mysql-fetch-field">
<refnamediv>
<refname>mysql_fetch_field</refname>
<refpurpose>
Get column information from a result and return as an object
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>object <function>mysql_fetch_field</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
<paramdef>int
<parameter>
<optional>field_offset</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns an object containing field information.
</para>
<para>
<function>mysql_fetch_field</function> can be used in order to
obtain information about fields in a certain query result. If
the field offset isn't specified, the next field that wasn't yet
retrieved by <function>mysql_fetch_field</function> is retrieved.
</para>
<para>
The properties of the object are:
<itemizedlist>
<listitem>
<simpara>
name - column name
</simpara>
</listitem>
<listitem>
<simpara>
table - name of the table the column belongs to
</simpara>
</listitem>
<listitem>
<simpara>
max_length - maximum length of the column
</simpara>
</listitem>
<listitem>
<simpara>
not_null - 1 if the column cannot be null
</simpara>
</listitem>
<listitem>
<simpara>
primary_key - 1 if the column is a primary key
</simpara>
</listitem>
<listitem>
<simpara>
unique_key - 1 if the column is a unique key
</simpara>
</listitem>
<listitem>
<simpara>
multiple_key - 1 if the column is a non-unique key
</simpara>
</listitem>
<listitem>
<simpara>
numeric - 1 if the column is numeric
</simpara>
</listitem>
<listitem>
<simpara>
blob - 1 if the column is a BLOB
</simpara>
</listitem>
<listitem>
<simpara>
type - the type of the column
</simpara>
</listitem>
<listitem>
<simpara>
unsigned - 1 if the column is unsigned
</simpara>
</listitem>
<listitem>
<simpara>
zerofill - 1 if the column is zero-filled
</simpara>
</listitem>
</itemizedlist>
</para>
<example>
<title><function>Mysql_fetch_field</function></title>
<programlisting role="php">
&lt;?php
mysql_connect ($host, $user, $password)
or die ("Could not connect");
$result = mysql_db_query ("database", "select * from table")
or die ("Query failed");
# get column metadata
$i = 0;
while ($i &lt; mysql_num_fields ($result)) {
echo "Information for column $i:&lt;BR>\n";
$meta = mysql_fetch_field ($result);
if (!$meta) {
echo "No information available&lt;BR>\n";
}
echo "&lt;PRE>
blob: $meta->blob
max_length: $meta->max_length
multiple_key: $meta->multiple_key
name: $meta->name
not_null: $meta->not_null
numeric: $meta->numeric
primary_key: $meta->primary_key
table: $meta->table
type: $meta->type
unique_key: $meta->unique_key
unsigned: $meta->unsigned
zerofill: $meta->zerofill
&lt;/PRE>";
$i++;
}
mysql_free_result ($result);
?>
</programlisting>
</example>
<para>
See also <function>mysql_field_seek</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-fetch-lengths">
<refnamediv>
<refname>mysql_fetch_lengths</refname>
<refpurpose>
Get the length of each output in a result
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>array <function>mysql_fetch_lengths</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns: An array that corresponds to the lengths of each field
in the last row fetched by <function>mysql_fetch_row</function>,
or false on error.
</para>
<para>
<function>mysql_fetch_lengths</function> stores the lengths of
each result column in the last row returned by
<function>mysql_fetch_row</function>,
<function>mysql_fetch_array</function>, and
<function>mysql_fetch_object</function> in an array, starting at
offset 0.
</para>
<para>
See also: <function>mysql_fetch_row</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-fetch-object">
<refnamediv>
<refname>mysql_fetch_object</refname>
<refpurpose>Fetch a result row as an object</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>object <function>mysql_fetch_object</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
<paramdef>int
<parameter>
<optional>result_type</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns an object with properties that correspond to the fetched
row, or false if there are no more rows.
</para>
<para>
<function>mysql_fetch_object</function> is similar to
<function>mysql_fetch_array</function>, with one difference - an
object is returned, instead of an array. Indirectly, that means
that you can only access the data by the field names, and not by
their offsets (numbers are illegal property names).
</para>
<para>
The optional argument <parameter>result_type</parameter> is a
constant and can take the following values: MYSQL_ASSOC,
MYSQL_NUM, and MYSQL_BOTH.
</para>
<para>
Speed-wise, the function is identical to
<function>mysql_fetch_array</function>, and almost as quick as
<function>mysql_fetch_row</function> (the difference is
insignificant).
<example>
<title><function>mysql_fetch_object</function> example</title>
<programlisting role="php">
&lt;?php
mysql_connect ($host, $user, $password);
$result = mysql_db_query ("database", "select * from table");
while ($row = mysql_fetch_object ($result)) {
echo $row->user_id;
echo $row->fullname;
}
mysql_free_result ($result);
?>
</programlisting>
</example>
</para>
<para>
See also: <function>mysql_fetch_array</function> and
<function>mysql_fetch_row</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-fetch-row">
<refnamediv>
<refname>mysql_fetch_row</refname>
<refpurpose>Get a result row as an enumerated array</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>array <function>mysql_fetch_row</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns: An array that corresponds to the fetched row, or false
if there are no more rows.
</para>
<para>
<function>mysql_fetch_row</function> fetches one row of data from
the result associated with the specified result identifier. The
row is returned as an array. Each result column is stored in an
array offset, starting at offset 0.
</para>
<para>
Subsequent call to <function>mysql_fetch_row</function> would
return the next row in the result set, or false if there are no
more rows.
</para>
<para>
See also: <function>mysql_fetch_array</function>,
<function>mysql_fetch_object</function>,
<function>mysql_data_seek</function>,
<function>mysql_fetch_lengths</function>, and
<function>mysql_result</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-field-flags">
<refnamediv>
<refname>mysql_field_flags</refname>
<refpurpose>
Get the flags associated with the specified field in a result
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>string <function>mysql_field_flags</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
<paramdef>int <parameter>field_offset</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_field_flags</function> returns the field flags of
the specified field. The flags are reported as a single word
per flag separated by a single space, so that you can split the
returned value using <function>explode</function>.
</para>
<para>The following flags are reported, if your version of MySQL
is current enough to support them: "not_null", "primary_key",
"unique_key", "multiple_key", "blob", "unsigned", "zerofill",
"binary", "enum", "auto_increment", "timestamp".
</para>
<para>
For downward compatibility <function>mysql_fieldflags</function>
can also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-field-name">
<refnamediv>
<refname>mysql_field_name</refname>
<refpurpose>
Get the name of the specified field in a result
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>string <function>mysql_field_name</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
<paramdef>int <parameter>field_index</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_field_name</function> returns the name of the
specified field index. <parameter>result</parameter> must be a
valid result identifier and <parameter>field_index</parameter> is
the numerical offset of the field.
</para>
<note>
<para>
<parameter>field_index</parameter> starts at 0.
</para>
<para>
e.g. The index of the third field would actually be 2, the index
of the fourth field would be 3 and so on.
</para>
</note>
<para>
<example>
<title><function>mysql_field_name</function> example</title>
<programlisting role="php">
// The users table consists of three fields:
// user_id
// username
// password.
$res = mysql_db_query("users", "select * from users", $link);
echo mysql_field_name($res, 0) . "\n";
echo mysql_field_name($res, 2);
</programlisting>
</example>
</para>
<para>
The above example would produce the following output:
<informalexample>
<programlisting>
user_id
password
</programlisting>
</informalexample>
</para>
<para>
For downwards compatibility <function>mysql_fieldname</function>
can also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-field-len">
<refnamediv>
<refname>mysql_field_len</refname>
<refpurpose>
Returns the length of the specified field
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_field_len</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
<paramdef>int <parameter>field_offset</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_field_len</function> returns the length of the
specified field.
</para>
<para>
For downward compatibility <function>mysql_fieldlen</function>
can also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-field-seek">
<refnamediv>
<refname>mysql_field_seek</refname>
<refpurpose>
Set result pointer to a specified field offset
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_field_seek</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
<paramdef>int <parameter>field_offset</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
Seeks to the specified field offset. If the next call to
<function>mysql_fetch_field</function> doesn't include a field
offset, the field offset specified in
<function>mysql_field_seek</function> will be returned.
</para>
<para>
See also: <function>mysql_fetch_field</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-field-table">
<refnamediv>
<refname>mysql_field_table</refname>
<refpurpose>
Get name of the table the specified field is in
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>string <function>mysql_field_table</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
<paramdef>int <parameter>field_offset</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns the name of the table that the specifed field is
in.
</para>
<para>
For downward compatibility <function>mysql_fieldtable</function>
can also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-field-type">
<refnamediv>
<refname>mysql_field_type</refname>
<refpurpose>
Get the type of the specified field in a result
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>string <function>mysql_field_type</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
<paramdef>int <parameter>field_offset</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_field_type</function> is similar to the
<function>mysql_field_name</function> function. The arguments are
identical, but the field type is returned instead. The field type
will be one of "int", "real", "string", "blob", and others as
detailed in the <ulink url="&url.mysql.docs;">MySQL
documentation</ulink>.
<example>
<title>mysql field types</title>
<programlisting role="php">
&lt;?php
mysql_connect ("localhost:3306");
mysql_select_db ("wisconsin");
$result = mysql_query ("SELECT * FROM onek");
$fields = mysql_num_fields ($result);
$rows = mysql_num_rows ($result);
$i = 0;
$table = mysql_field_table ($result, $i);
echo "Your '".$table."' table has ".$fields." fields and ".$rows." records &lt;BR>";
echo "The table has the following fields &lt;BR>";
while ($i &lt; $fields) {
$type = mysql_field_type ($result, $i);
$name = mysql_field_name ($result, $i);
$len = mysql_field_len ($result, $i);
$flags = mysql_field_flags ($result, $i);
echo $type." ".$name." ".$len." ".$flags."&lt;BR>";
$i++;
}
mysql_close();
?>
</programlisting>
</example>
</para>
<para>
For downward compatibility <function>mysql_fieldtype</function>
can also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-free-result">
<refnamediv>
<refname>mysql_free_result</refname>
<refpurpose>Free result memory</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_free_result</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_free_result</function> will free all memory
associated with the result identifier <parameter>result</parameter>.
</para>
<para>
<function>mysql_free_result</function> only needs to be called if
you are concerned about how much memory is being used for queries
that return large result sets. All associated result memory is
automatically freed at the end of the script's execution.
</para>
<para>
For downward compatibility <function>mysql_freeresult</function>
can also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-insert-id">
<refnamediv>
<refname>mysql_insert_id</refname>
<refpurpose>
Get the id generated from the previous INSERT operation
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_insert_id</function></funcdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_insert_id</function> returns the ID generated for
an AUTO_INCREMENT field. It will return the auto-generated ID
returned by the last INSERT query performed using the given
<parameter>link_identifier</parameter>. If
<parameter>link_identifier</parameter> isn't specified, the last
opened link is assumed.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-list-dbs">
<refnamediv>
<refname>mysql_list_dbs</refname>
<refpurpose>
List databases available on a MySQL server
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_list_dbs</function></funcdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_list_dbs</function> will return a result pointer
containing the databases available from the current mysql
daemon. Use the <function>mysql_tablename</function> function to
traverse this result pointer.
</para>
<para>
<example>
<title><function>mysql_list_dbs</function> example</title>
<programlisting role="php">
$link = mysql_connect('localhost', 'myname', 'secret');
$db_list = mysql_list_dbs($link);
while ($row = mysql_fetch_object($db_list)) {
echo $row->Database . "\n";
}
</programlisting>
</example>
</para>
<para>
The above example would produce the following output:
<informalexample>
<programlisting>
database1
database2
database3
...
</programlisting>
</informalexample>
</para>
<note>
<para>
The above code would just as easily work with
<function>mysql_fetch_row</function> or other similar functions.
</para>
</note>
<para>
For downward compatibility <function>mysql_listdbs</function> can
also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-list-fields">
<refnamediv>
<refname>mysql_list_fields</refname>
<refpurpose>List MySQL result fields</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_list_fields</function></funcdef>
<paramdef>string <parameter>database_name</parameter></paramdef>
<paramdef>string <parameter>table_name</parameter></paramdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_list_fields</function> retrieves information
about the given tablename. Arguments are the database name and
the table name. A result pointer is returned which can be used
with <function>mysql_field_flags</function>,
<function>mysql_field_len</function>,
<function>mysql_field_name</function>, and
<function>mysql_field_type</function>.
</para>
<para>
A result identifier is a positive integer. The function returns
-1 if a error occurs. A string describing the error will be
placed in <literal>$phperrmsg</literal>, and unless the function
was called as <literal>@mysql()</literal> then this error string
will also be printed out.
</para>
<para>
<example>
<title><function>mysql_list_fields</function> example</title>
<programlisting role="php">
$link = mysql_connect('localhost', 'myname', 'secret');
$fields = mysql_list_fields("database1", "table1", $link);
$columns = mysql_num_fields($fields);
for ($i = 0; $i < $columns; $i++) {
echo mysql_field_name($fields, $i) . "\n";;
}
</programlisting>
</example>
</para>
<para>
The above example would produce the following output:
<informalexample>
<programlisting>
field1
field2
field3
...
</programlisting>
</informalexample>
</para>
<para>
For downward compatibility <function>mysql_listfields</function>
can also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-list-tables">
<refnamediv>
<refname>mysql_list_tables</refname>
<refpurpose>List tables in a MySQL database</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_list_tables</function></funcdef>
<paramdef>string <parameter>database</parameter></paramdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_list_tables</function> takes a database name and
returns a result pointer much like the
<function>mysql_db_query</function> function. The
<function>mysql_tablename</function> function should be used to
extract the actual table names from the result pointer.
</para>
<para>
For downward compatibility <function>mysql_listtables</function>
can also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-num-fields">
<refnamediv>
<refname>mysql_num_fields</refname>
<refpurpose>Get number of fields in result</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_num_fields</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_num_fields</function> returns the number of
fields in a result set.
</para>
<para>
See also:
<function>mysql_db_query</function>,
<function>mysql_query</function>,
<function>mysql_fetch_field</function>,
<function>mysql_num_rows</function>.</para>
<para>
For downward compatibility <function>mysql_numfields</function>
can also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-num-rows">
<refnamediv>
<refname>mysql_num_rows</refname>
<refpurpose>Get number of rows in result</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_num_rows</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_num_rows</function> returns the number of rows in
a result set. This command is only valid for SELECT statements.
To retrieve the number of rows returned from a INSERT, UPDATE or
DELETE, use <function>mysql_affected_rows</function>.
</para>
<para>
See also:
<function>mysql_db_query</function>,
<function>mysql_query</function> and,
<function>mysql_fetch_row</function>.
</para>
<para>
For downward compatibility <function>mysql_numrows</function> can
also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-pconnect">
<refnamediv>
<refname>mysql_pconnect</refname>
<refpurpose>
Open a persistent connection to a MySQL Server
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_pconnect</function></funcdef>
<paramdef>string
<parameter>
<optional>hostname
<optional>:port</optional>
<optional>:/path/to/socket</optional>
</optional>
</parameter>
</paramdef>
<paramdef>string
<parameter><optional>username</optional></parameter>
</paramdef>
<paramdef>string
<parameter><optional>password</optional></parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns: A positive MySQL persistent link identifier on success,
or false on error.
</para>
<para>
<function>mysql_pconnect</function> establishes a connection
to a MySQL server. The following defaults are assumed for
missing optional parameters: <parameter>host:port</parameter> =
'localhost:3306', <parameter>username</parameter> = name of the
user that owns the server process and
<parameter>password</parameter> = empty password.
</para>
<para>
The hostname string can also include a port
number. eg. &quot;hostname:port&quot; or a path to a socket
eg. &quot;:/path/to/socket&quot; for the localhost.
<note>
<para>
Support for &quot;:port&quot; wass added in 3.0B4.
</para>
<para>
Support for the &quot;:/path/to/socket&quot; was added in
3.0.10.
</para>
</note>
</para>
<para>
<function>mysql_pconnect</function> acts very much like
<function>mysql_connect</function> with two major differences.
</para>
<para>
First, when connecting, the function would first try to find a
(persistent) link that's already open with the same host,
username and password. If one is found, an identifier for it
will be returned instead of opening a new connection.
</para>
<para>
Second, the connection to the SQL server will not be closed when
the execution of the script ends. Instead, the link will remain
open for future use (<function>mysql_close</function> will not
close links established by <function>mysql_pconnect</function>).
</para>
<para>
This type of links is therefore called 'persistent'.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-query">
<refnamediv>
<refname>mysql_query</refname>
<refpurpose>Send a MySQL query</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_query</function></funcdef>
<paramdef>string <parameter>query</parameter></paramdef>
<paramdef>int
<parameter><optional>link_identifier</optional></parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_query</function> sends a query to the currently
active database on the server that's associated with the
specified link identifier. If
<parameter>link_identifier</parameter> isn't specified, the last
opened link is assumed. If no link is open, the function tries
to establish a link as if <function>mysql_connect</function> was
called with no arguments, and use it.
</para>
<note>
<para>
The query string should not end with a semicolon.
</para>
</note>
<para>
<function>mysql_query</function> returns TRUE (non-zero) or FALSE
to indicate whether or not the query succeeded. A return value
of TRUE means that the query was legal and could be executed by
the server. It does not indicate anything about the number of
rows affected or returned. It is perfectly possible for a query
to succeed but affect no rows or return no rows.
</para>
<para>
The following query is syntactically invalid, so
<function>mysql_query</function> fails and returns FALSE:
<example>
<title><function>mysql_query</function></title>
<programlisting role="php">
&lt;?php
$result = mysql_query ("SELECT * WHERE 1=1")
or die ("Invalid query");
?>
</programlisting>
</example>
</para>
<para>
The following query is semantically invalid if
<literal>my_col</literal> is not a column in the table
<literal>my_tbl</literal>, so <function>mysql_query</function>
fails and returns FALSE:
<example>
<title><function>mysql_query</function></title>
<programlisting role="php">
&lt;?php
$result = mysql_query ("SELECT my_col FROM my_tbl")
or die ("Invalid query");
?>
</programlisting>
</example>
</para>
<para>
<function>mysql_query</function> will also fail and return FALSE
if you don't have permission to access the table(s) referenced by
the query.
</para>
<para>
Assuming the query succeeds, you can call
<function>mysql_num_rows</function> to find out how many rows
were returned for a SELECT statment or
<function>mysql_affected_rows</function> to find out how many
rows were affected by a DELETE, INSERT, REPLACE, or UPDATE
statement.
</para>
<para>
For SELECT statements, <function>mysql_query</function> returns a
new result identifier that you can pass to
<function>mysql_result</function>. When you are done with the
result set, you can free the resources associated with it by
calling <function>mysql_free_result</function>. Although, the
memory will automatically be freed at the end of the script's
execution.
</para>
<para>
See also: <function>mysql_affected_rows</function>,
<function>mysql_db_query</function>,
<function>mysql_free_result</function>,
<function>mysql_result</function>,
<function>mysql_select_db</function>, and
<function>mysql_connect</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-result">
<refnamediv>
<refname>mysql_result</refname>
<refpurpose>Get result data</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_result</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
<paramdef>int <parameter>row</parameter></paramdef>
<paramdef>mixed
<parameter>
<optional>field</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_result</function> returns the contents of one
cell from a MySQL result set. The field argument can be the
field's offset, or the field's name, or the field's table dot
field's name (fieldname.tablename). If the column name has been
aliased ('select foo as bar from...'), use the alias instead of
the column name.
</para>
<para>
When working on large result sets, you should consider using one
of the functions that fetch an entire row (specified below). As
these functions return the contents of multiple cells in one
function call, they're MUCH quicker than
<function>mysql_result</function>. Also, note that specifying a
numeric offset for the field argument is much quicker than
specifying a fieldname or tablename.fieldname argument.
</para>
<para>
Calls to <function>mysql_result</function> should not be mixed
with calls to other functions that deal with the result set.
</para>
<para>
Recommended high-performance alternatives:
<function>mysql_fetch_row</function>,
<function>mysql_fetch_array</function>, and
<function>mysql_fetch_object</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-select-db">
<refnamediv>
<refname>mysql_select_db</refname>
<refpurpose>Select a MySQL database</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>mysql_select_db</function></funcdef>
<paramdef>string <parameter>database_name</parameter></paramdef>
<paramdef>int
<parameter>
<optional>link_identifier</optional>
</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
Returns: true on success, false on error.
</para>
<para>
<function>mysql_select_db</function> sets the current active
database on the server that's associated with the specified link
identifier. If no link identifier is specified, the last opened
link is assumed. If no link is open, the function will try to
establish a link as if <function>mysql_connect</function> was
called, and use it.
</para>
<para>
Every subsequent call to <function>mysql_query</function> will be
made on the active database.
</para>
<para> See also:
<function>mysql_connect</function>,
<function>mysql_pconnect</function>, and
<function>mysql_query</function>.
</para>
<para>
For downward compatibility <function>mysql_selectdb</function>
can also be used.
</para>
</refsect1>
</refentry>
<refentry id="function.mysql-tablename">
<refnamediv>
<refname>mysql_tablename</refname>
<refpurpose>Get table name of field</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>string <function>mysql_tablename</function></funcdef>
<paramdef>int <parameter>result</parameter></paramdef>
<paramdef>int <parameter>i</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>mysql_tablename</function> takes a result pointer
returned by the <function>mysql_list_tables</function> function
as well as an integer index and returns the name of a table. The
<function>mysql_num_rows</function> function may be used to
determine the number of tables in the result pointer.
<example>
<title><function>Mysql_tablename</function> Example</title>
<programlisting role="php">
&lt;?php
mysql_connect ("localhost:3306");
$result = mysql_list_tables ("wisconsin");
$i = 0;
while ($i &lt; mysql_num_rows ($result)) {
$tb_names[$i] = mysql_tablename ($result, $i);
echo $tb_names[$i] . "&lt;BR>";
$i++;
}
?>
</programlisting>
</example>
</para>
</refsect1>
</refentry>
</reference>
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