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    pg_field_size

    (PHP 4 >= 4.2.0, PHP 5, PHP 7)

    pg_field_size — Returns the internal storage size of the named field

    설명

    int pg_field_size ( resource $result , int $field_number )

    pg_field_size() returns the internal storage size (in bytes) of the field number in the given PostgreSQL result.

    Note:

    This function used to be called pg_fieldsize().

    인수

    result

    PostgreSQL query result resource, returned by pg_query(), pg_query_params() or pg_execute() (among others).

    field_number

    Field number, starting from 0.

    반환값

    The internal field storage size (in bytes). -1 indicates a variable length field. FALSE is returned on error.

    예제

    Example #1 Getting information about fields

    <?php
      $dbconn     = pg_connect("dbname=publisher") or die("Could not connect");

          $res = pg_query($dbconn, "select * from authors where author = 'Orwell'");
          $i = pg_num_fields($res);
      for (    $j = 0; $j < $i; $j++) {
          echo     "column $j\n";
              $fieldname = pg_field_name($res, $j);
          echo     "fieldname: $fieldname\n";
          echo     "printed length: " . pg_field_prtlen($res, $fieldname) . " characters\n";
          echo     "storage length: " . pg_field_size($res, $j) . " bytes\n";
          echo     "field type: " . pg_field_type($res, $j) . " \n\n";
      }
    ?>

    위 예제의 출력:

    column 0
fieldname: author
printed length: 6 characters
storage length: -1 bytes
field type: varchar 

column 1
fieldname: year
printed length: 4 characters
storage length: 2 bytes
field type: int2 

column 2
fieldname: title
printed length: 24 characters
storage length: -1 bytes
field type: varchar

    참고

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    User Contributed Notes 3 notes

    up
    0
    ij at NOSPAM dot irj dot co dot za
    19 years ago
    To view the file structure of a table using a sql query

    select pg_class.relname, pg_attribute.attname, pg_type.typname, pg_type.typlen from pg_class, pg_attribute, pg_type  where pg_class.relname = 'YOURTABLENAME' and pg_class.oid = pg_attribute.attrelid and pg_type.oid = pg_attribute.atttypid having attnum > 0
    up
    0
    php at tribun dot de
    19 years ago
    function get_create_syntax( $table )
    {
      $qry  =  "
                SELECT    *
                FROM      $table
                LIMIT     1
              ";
      $res = pg_query( $qry );
      $row = pg_fetch_assoc( $res );

      $create = "CREATE TABLE $table \n(\n";

      $item = array();
      for( $i = 0; $i < count( $row ); $i++ )
      {
        $name = pg_field_name( $res, $i );
        $type = pg_field_type( $res, $i );
        $size = pg_field_size( $res, $i );

        $item[$i] = '"'.$name.'" '.$type;

        $qry  =  "
                  SELECT    a.atttypmod    AS size,
                            a.attnotnull  AS notnull
                  FROM      pg_attribute  AS a,
                            pg_class      AS c
                  WHERE     c.relname   = '$table'
                  AND       a.attrelid  =  c.oid
                  AND       a.attname    =  '$name'
                 ";
        $res2  = pg_query( $qry );
        $out  = pg_fetch_object( $res2 );

        if( $out -> size != -1 )
        {
          $item[$i] .= '('.( $out -> size - 4 ).')';
        }
        if( $out -> notnull == 't' )
        $item[$i] .= ' NOT';

        $item[$i] .= ' NULL';

      }
      $create .= implode( ",\n", $item ) ."\n);";

      return $create;
    }
    up
    -2
    alex at linuxNOSPAM dot org dot pe
    22 years ago
    How i can extract the struct of a Postgresql Table?

    I want to do a dynamic php code, that see the pg table, and print name, type and size of fields
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