mysql_field_len () function and more for postgres ...
problems ...
* pg_field_prtlen ... gives the actual size of the field back (it shows the count of the content allready inside the field - not the possible max-len)
* pg_filed_size ... can't be used for varchar or bpchar fields
...but there is a way to get the real-max-length of a field in postgreSQL via the system tables:
//returns an array with infos of every field in the table (name, type, length, size)
function SQLConstructFieldsInfo($TABLE, $DBCON)
{
$s="SELECT a.attname AS name, t.typname AS type, a.attlen AS size, a.atttypmod AS len, a.attstorage AS i
FROM pg_attribute a , pg_class c, pg_type t
WHERE c.relname = '$TABLE'
AND a.attrelid = c.oid AND a.atttypid = t.oid";
if ($r = pg_query($DBCON,$s))
{
$i=0;
while ($q = pg_fetch_assoc($r))
{
$a[$i]["type"]=$q["type"];
$a[$i]["name"]=$q["name"];
if($q["len"]<0 && $q["i"]!="x")
{
// in case of digits if needed ... (+1 for negative values)
$a[$i]["len"]=(strlen(pow(2,($q["size"]*8)))+1);
}
else
{
$a[$i]["len"]=$q["len"];
}
$a[$i]["size"]=$q["size"];
$i++;
}
return $a;
}
return null;
}
// usage
$DBCON=pg_connect("host=YOUR-HOST port=YOUR-PORT dbname=YOUR-DB user=YOUR-USER password=YOUR-PASS");
$TABLE="YOUR-TABLENAME";
$RET=SQLConstructFieldsInfo($TABLE, $DBCON);
$j = count($RET);
for ($i=0; $i < $j; $i++)
{
echo "<br>$i name=".$RET[$i]["name"]." type=".$RET[$i]["type"]." length=".$RET[$i]["len"]." size=".$RET[$i]["size"]." bytes";
}
pg_field_prtlen
说明
int pg_field_prtlen ( resource result, int row_number, string field_name )pg_field_prtlen() 返回 PostgreSQL result 中得到的值实际上打印出来的长度（字符数）。行编号从 0 开始。如果出错本函数返回 -1。
例子参见 pg_field_name() 页。
注: 本函数以前的名字为 pg_field_prtlen()。
参见 pg_field_size()。
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User Contributed Notes
r dot galovic at r-3 dot at
19-Apr-2005 04:54
19-Apr-2005 04:54