mysql_field_seek
The function below takes a function and returns the col->table mapping as an array.
For example:
$query = “SELECT a.id AS a_id, b.id b_id FROM atable AS a, btable b”
$cols = queryAlias($query);
print_r($cols);
Returns:
Array
(
[a] => atable
[b] => btable
)
I can't promise it's perfect, but this function never hit production cause I ended up using mysqli methods instead.
Enjoy
-Jorge
/**
* Takes in a query and returns the alias->table mapping.
*
* @param string $query
* @return array of alias mapping
*/
function queryAlias ( $query ) {
//Make it all lower, we ignore case
$substr = strtolower($query);
//Remove any subselects
$substr = preg_replace ( ‘/\(.*\)/’, ”, $substr);
//Remove any special charactors
$substr = preg_replace ( ‘/[^a-zA-Z0-9_,]/’, ‘ ‘, $substr);
//Remove any white space
$substr = preg_replace(‘/\s\s+/’, ‘ ‘, $substr);
//Get everything after FROM
$substr = strtolower(substr($substr, strpos(strtolower($substr),‘ from ‘) + 6));
//Rid of any extra commands
$substr = preg_replace(
Array(
‘/ where .*+$/’,
‘/ group by .*+$/’,
‘/ limit .*+$/’ ,
‘/ having .*+$/’ ,
‘/ order by .*+$/’,
‘/ into .*+$/’
), ”, $substr);
//Remove any JOIN modifiers
$substr = preg_replace(
Array(
‘/ left /’,
‘/ right /’,
‘/ inner /’,
‘/ cross /’,
‘/ outer /’,
‘/ natural /’,
‘/ as /’
), ‘ ‘, $substr);
//Replace JOIN statements with commas
$substr = preg_replace(Array(‘/ join /’, ‘/ straight_join /’), ‘,’, $substr);
$out_array = Array();
//Split by FROM statements
$st_array = split (‘,’, $substr);
foreach ($st_array as $col) {
$col = preg_replace(Array(‘/ on .*+/’), ”, $col);
$tmp_array = split(‘ ‘, trim($col));
//Oh no, something is wrong, let’s just continue
if (!isset($tmp_array[0]))
continue;
$first = $tmp_array[0];
//If the “AS” is set, lets include that, if not, well, guess this table isn’t aliased.
if (isset($tmp_array[1]))
$second = $tmp_array[1];
else
$second = $first;
if (strlen($first))
$out_array[$second] = $first;
}
return $out_array;
}
mysql_field_table
(PHP 4, PHP 5, PECL mysql:1.0)
mysql_field_table — 특정 필드가 속한 테이블명을 얻음
설명
string mysql_field_table
( resource $result
, int $field_offset
)
특정 필드가 속한 테이블명을 반환한다.
매개변수
- result
-
mysql_query() 호출을 통한 결과 resource.
- field_offset
-
The numerical field offset. The field_offset starts at 0. If field_offset does not exist, an error of level E_WARNING is also issued.
반환값
성공하면 테이블명을 반환.
예제
Example#1 A mysql_field_table() 예제
<?php
$result = mysql_query("SELECT name,comment FROM people,comments");
if (!$result) {
echo 'Could not run query: ' . mysql_error();
exit;
}
// Assuming name is in the people table
$table = mysql_field_table($result, 'name');
echo $table; // people
?>
주의
Note: 하위 호환을 위하여, 다음의 권장하지 않는 alias를 사용할 수 있습니다: mysql_fieldtable()
add a note
User Contributed Notesmysql_field_table
jorge at rhst dot net
29-Jul-2007 02:57
29-Jul-2007 02:57
spam at blondella dot de
03-Oct-2006 04:09
03-Oct-2006 04:09
<?php
/*
this function might help in the case described above :-)
*/
function mysql_field_table_resolve_alias($inQuery,$inResult,$inFieldName) {
$theNameOrAlias = mysql_field_table($inResult,$inFieldName);
//check, if AS syntax is being used
if(ereg(" AS ",$inQuery)) {
//catch words in query
$theWords = explode(" ",ereg_replace(",|\n"," ",$inQuery));
//find the words preceding and following AS
foreach($theWords as $theIndex => $theWord) {
if(trim($theWord) == "AS"
&& isset($theWords[$theIndex-1])
&& isset($theWords[$theIndex+1])
&& $theWords[$theIndex+1] == $theNameOrAlias
) {
$theNameOrAlias = $theWords[$theIndex-1];
break 1;
}
}
}
return $theNameOrAlias;
}
?>
me at thomaskeller dot biz
23-Nov-2005 01:15
23-Nov-2005 01:15
Beware that if you upgrade to MySQL 5 from any earlier version WITHOUT dumping and reloading your data (just by keeping the binary data in MyISAM table files), you might get weird output on the "table" value for mysql_fetch_field and in this function. Weird means that the table name is randomly set or not.
This behaviour seems to popup only if the SQL query contains a ORDER BY clause. A bug is already reported:
http://bugs.mysql.com/bug.php?id=14915
To prevent the issue, dump and reload all participating tables in your query or do
CREATE TABLE tmp SELECT * FROM table;
DROP TABLE table;
ALTER TABLE tmp RENAME table;
on each one via commandline client.
cptnemo
14-Aug-2004 07:18
14-Aug-2004 07:18
When trying to find table names for a (My)SQL query containing 'tablename AS alias', mysql_field_table() only returns the alias as specified in the AS clause, and not the tablename.