# fbsql_fetch_field

(PHP 4 >= 4.0.6, PHP 5, PHP 7)

fbsql_fetch_field — Get column information from a result and return as an object

### 说明

fbsql_fetch_field ( resource `$result` [, int `$field_offset` ] ) : object

Used in order to obtain information about fields in a certain query result.

### 参数

`result`

  由 fbsql_query() 或 fbsql_db_query() 返回的结果标识符。

`field_offset`

  The numerical offset of the field. The field index starts at 0. If not specified, the next field that wasn't yet retrieved by fbsql_fetch_field() is retrieved.

### 返回值

Returns an object containing field information, or `FALSE` on errors.

The properties of the object are:

- name - column name
- table - name of the table the column belongs to
- max_length - maximum length of the column
- not_null - 1 if the column cannot be `NULL`
- type - the type of the column

### 范例

Example #1 fbsql_fetch_field() example

    <?php
    fbsql_connect($host, $user, $password)
        or die("Could not connect");
    $result = fbsql_db_query("database", "select * from table")
        or die("Query failed");
    # get column metadata
    $i = 0;
    while ($i < fbsql_num_fields($result)) {
        echo "Information for column $i:<br />\n";
        $meta = fbsql_fetch_field($result);
        if (!$meta) {
            echo "No information available<br />\n";
        }
        echo "<pre>
    max_length:   $meta->max_length
    name:         $meta->name
    not_null:     $meta->not_null
    table:        $meta->table
    type:         $meta->type
    </pre>";
        $i++;
    }
    fbsql_free_result($result);
    ?>

### 参见

- fbsql_field_seek() - Set result pointer to a specified field offset