dbx_query

Podręcznik PHP
Poprzedni		Następny

Description

object dbx_query ( object link_identifier, string sql_statement [, long flags])

dbx_query() returns an object or 1 on success, and 0 on failure. The result object is returned only if the query given in sql_statement produces a result set.

Przykład 1. How to handle the returned value

<?php
$link   = dbx_connect(DBX_ODBC, "", "db", "username", "password")
    or die("Could not connect");

$result = dbx_query($link, 'SELECT id, parentid, description FROM table');

if ( is_object($result) ) {
    // ... do some stuff here, see detailed examples below ...
    // first, print out field names and types 
    // then, draw a table filled with the returned field values
}
else if ( $result == 1 ) {
    echo("Query executed successfully, but no result set returned");
}
else {
    exit("Query failed");
}

dbx_close($link);
?>

The flags parameter is used to control the amount of information that is returned. It may be any combination of the following constants with the bitwise OR operator (|):

DBX_RESULT_INDEX

It is always set, that is, the returned object has a data property which is a 2 dimensional array indexed numerically. For example, in the expression data[2][3] 2 stands for the row (or record) number and 3 stands for the column (or field) number. The first row and column are indexed at 0.

If DBX_RESULT_ASSOC is also specified, the returning object contains the information related to DBX_RESULT_INFO too, even if it was not specified.

DBX_RESULT_INFO

It provides info about columns, such as field names and field types.

DBX_RESULT_ASSOC

It effects that the field values can be accessed with the respective column names used as keys to the returned object's data property.

Associated results are actually references to the numerically indexed data, so modifying data[0][0] causes that data[0]['field_name_for_first_column'] is modified as well.

Note that DBX_RESULT_INDEX is always used, regardless of the actual value of flags parameter. This means that the following combinations is effective only:

DBX_RESULT_INDEX
DBX_RESULT_INDEX | DBX_RESULT_INFO
DBX_RESULT_INDEX | DBX_RESULT_INFO | DBX_RESULT_ASSOC - this is the default, if flags is not specified.

The returing object has four or five properties depending on flags:

handle

It is a valid handle for the connected database, and as such it can be used in module specific functions (if required).

$result = dbx_query ($link, "SELECT id FROM table");
mysql_field_len ($result->handle, 0);

cols and rows

These contain the number of columns (or fields) and rows (or records) respectively.

$result = dbx_query ($link, 'SELECT id FROM table');
echo $result->rows; // number of records
echo $result->cols; // number of fields

info (optional)

It is returned only if either DBX_RESULT_INFO or DBX_RESULT_ASSOC is specified in the flags parameter. It is a 2 dimensional array, that has two named rows (name and type) to retrieve column information.

Przykład 2. lists each field's name and type

$result = dbx_query ($link, 'SELECT id FROM table', DBX_RESULT_INDEX | DBX_RESULT_INFO);

for ($i = 0; $i < $result->cols; $i++ ) {
    echo $result->info['name'][$i] . "\n";
    echo $result->info['type'][$i] . "\n";  
}

data

This property contains the actual resulting data, possibly associated with column names as well depending on flags. If DBX_RESULT_ASSOC is set, it is possible to use $result->data[2]["field_name"].

Przykład 3. outputs the content of data property into HTML table

$result = dbx_query ($link, 'SELECT id, parentid, description FROM table');

echo "<table>\n";
foreach ( $result->data as $row ) {
    echo "<tr>\n";
    foreach ( $row as $field ) {
        echo "<td>$field</td>";
    }
    echo "</tr>\n";
}
echo "</table>\n";

Notatka: Always refer to the module-specific documentation as well.

Poprzedni	Spis treści	Następny
dbx_error	Początek rozdziału	dbx_sort