(PHP 5, PHP 7, PHP 8)
mysqli_stmt::attr_set -- mysqli_stmt_attr_set — Used to modify the behavior of a prepared statement
面向对象风格
$attribute, int $value): bool过程化风格
Used to modify the behavior of a prepared statement. This function may be called multiple times to set several attributes.
statement仅以过程化样式:由 mysqli_stmt_init() 返回的 mysqli_stmt 对象。
attributeThe attribute that you want to set. It can have one of the following values:
| Character | Description | 
|---|---|
| MYSQLI_STMT_ATTR_UPDATE_MAX_LENGTH | Setting to truecauses mysqli_stmt_store_result() to
            update the metadataMYSQL_FIELD->max_lengthvalue. | 
| MYSQLI_STMT_ATTR_CURSOR_TYPE | Type of cursor to open for statement when mysqli_stmt_execute()
            is invoked. valuecan beMYSQLI_CURSOR_TYPE_NO_CURSOR(the default) orMYSQLI_CURSOR_TYPE_READ_ONLY. | 
| MYSQLI_STMT_ATTR_PREFETCH_ROWS | Number of rows to fetch from server at a time when using a cursor. valuecan be in the range from 1 to the maximum
            value of unsigned long. The default is 1. | 
       If you use the MYSQLI_STMT_ATTR_CURSOR_TYPE option with
       MYSQLI_CURSOR_TYPE_READ_ONLY, a cursor is opened for the
       statement when you invoke mysqli_stmt_execute(). If there
       is already an open cursor from a previous mysqli_stmt_execute() call,
       it closes the cursor before opening a new one. mysqli_stmt_reset()
       also closes any open cursor before preparing the statement for re-execution.
       mysqli_stmt_free_result() closes any open cursor.
      
If you open a cursor for a prepared statement, mysqli_stmt_store_result() is unnecessary.
valueThe value to assign to the attribute.
   成功时返回 true, 或者在失败时返回 false。