mysql_list_dbs
Every my html table output begins with heading row containing the field names. For that purpose I accepted the short combination of MySQL function, giving me a result similar to the mysql_fetch_array() for the row of values. The following example shows the basic idea. It should be adapted for the specific use:
<?php
//...
$field_names = array_keys( mysql_fetch_array( mysql_query( $query, $link), MYSQL_ASSOC));
//...
?>
The advantage of this is, that it gives the names of the result, neither the field names of the whole table.
Please read the discussion about duplicate field names in SQL result carefully. The use, as shown in the example above, increments the pointer, hence some regular function, which does not, could be more useful :-)
Jan
mysql_list_fields
(PHP 4, PHP 5)
mysql_list_fields — Lista os campos de uma tabela MySQL
Descrição
resource mysql_list_fields
( string $database_name
, string $table_name
[, resource $link_identifier
] )
Obtém informações sobre o nome de tabela dado.
Esta função esta obsoleta. É preferrível usar mysql_query() para realizar uma consulta SQL SHOW COLUMNS FROM table [LIKE 'name'] ao invés.
Parâmetros
- database_name
-
O nome do banco de dados que esta sendo consultado.
- table_name
-
O nome da tabela que esta sendo consultada.
- link_identifier
-
A conexão MySQL. se o identificador de conexão não for especificado, a ultima conexão aberta por mysql_connect() é assumida. Se uma conexão assim não for encontrada, ela irá tentar criar uma como se a função mysql_connect() fosse chamada sem argumentos. Se uma conexão não for encontrada ou estabelecida, um aviso de nível de erro E_WARNING é gerado.
Valor Retornado
Um ponteiro de recurso resource em caso de sucesso, ou FALSE em caso de falha.
O ponteiro de resultado pode ser usado com mysql_field_flags(), mysql_field_len(), mysql_field_name() e mysql_field_type().
Exemplos
Exemplo #1 Alternativa para o obsoleto mysql_list_fields()
<?php
$result = mysql_query("SHOW COLUMNS FROM sometable");
if (!$result) {
echo 'Could not run query: ' . mysql_error();
exit;
}
if (mysql_num_rows($result) > 0) {
while ($row = mysql_fetch_assoc($result)) {
print_r($row);
}
}
?>
O exemplo acima irá imprimir algo similar a:
Array
(
[Field] => id
[Type] => int(7)
[Null] =>
[Key] => PRI
[Default] =>
[Extra] => auto_increment
)
Array
(
[Field] => email
[Type] => varchar(100)
[Null] =>
[Key] =>
[Default] =>
[Extra] =>
)
Notas
Nota: Para compatibilidade com versões anteriores, o seguinte apelido obsoleto pode ser usado: mysql_listfields()
Veja Também
- mysql_field_flags() - Obtém as flags associadas ao campo especificado em um resultado
- mysql_info() - Obtém informação sobre a consulta mais recente
add a note
User Contributed Notesmysql_list_fields
perwool at seznam dot cz
29-Oct-2007 10:32
29-Oct-2007 10:32
steve at tequilasolutions dot com
12-Sep-2006 01:33
12-Sep-2006 01:33
Note, using mysql_list_fields will change the currently selected database so subsequent mysql_query operations will be on the database in param 1 not the one selected with mysql_select_db
rhyous at yahoo dot com
04-Jun-2005 10:22
04-Jun-2005 10:22
To make an array containing the names of a column from a table, you use the following simple script: (Note: using table1 with three columns)
<?php
$qColumnNames = mysql_query("SHOW COLUMNS FROM table1",$db) or die("mysql error");
$numColumns = mysql_num_rows($qColumnNames);
$x = 0;
while ($x < $numColumns)
{
$colname = mysql_fetch_row($qColumnNames);
$col[$colname[0]] = $colname[0];
$x++;
}
print_r($col);
/* it will have the following output
Array (
[firstcolumn] => firstcolumn
[secondcolumn] => secondcolumn
[thirdcolumn] => thirdcolumn
)
*/
?>
Or you can number the columns from zero. This help when using it in conjunction with mysql_fetch_row to get an array. You don't have to remember which number of the array a certain column is.
<?php
$qColumnNames = mysql_query("SHOW COLUMNS FROM table1",$db) or die("mysql error");
$numColumns = mysql_num_rows($qColumnNames);
$x = 0;
while ($x < $numColumns)
{
$colname = mysql_fetch_row($qColumnNames);
$col[$colname[0]] = $x;
$x++;
}
print_r($col);
/* it will have the following output
Array (
[firstcolumn] => 0
[secondcolumn] => 1
[thirdcolumn] => 2
)
*/
?>
To use it in conjuction with mysql_fetch_row:
<?php
$row = mysql_fetch_row("SELECT * from table1",$db) or die("mysql error");
?>
You can now call $row[col[firstcolumn]]. This becomes useful when you have a lot of columns.
mbevan at marginsoftware dot com
13-Nov-2003 09:40
13-Nov-2003 09:40
If you're willing to use a lot of functions to get a little information about fields in a table, this function is for you. If you just want to get all the information you can find, you can use this:
<?php
// Taken from: http://ca.php.net/manual/en/function.mysql-field-flags.php
// Original by: amir at scrounch dot com
// Returns the name of the fields in the primary key for a table.
// Also keeps the fields in KEY order. Handy.
function getPrimaryKeyOf($table) {
$keys = Array();
$query = sprintf("SHOW KEYS FROM `%s`", $table);
$result = mysql_query($query) or die(mysql_error());
while ($row = mysql_fetch_assoc($result)) {
if ( $row['Key_name'] == 'PRIMARY' )
$keys[$row['Seq_in_index'] - 1] = $row['Column_name'];
}
return $keys;
}
// Returns a bunch of information about a table...
// The name of the auto-increment field, if any, fields in the
// primary key (using the function above), and all information
// about all fields.
function getTableInformationOf($table) {
$information = array(
"auto" => "",
"primary" => array(),
"fields" => array()
);
$information['primary'] = $this->getPrimaryKeyOf($table);
$result = mysql_query("DESC `$table`");
while ( $field = mysql_fetch_assoc($result) ) {
$information['fields'][] = $field;
if ( $field['Extra'] == "auto_increment" )
$information['auto'] = $field['Field'];
}
return $information;
}
?>
dom at brainwaveuk dot com
19-Jul-2002 02:55
19-Jul-2002 02:55
mysql_list_fields() retrieves information about the given table name but you can use something like mysql_fetch_field to retrieve the field names from a result source.