tailieunhanh - Hướng dẫn sử dụng MySQL part 18

Trong Chương XXX: Bảo mật, chúng tôi đã thấy cách sử dụng MySQL bảng riêng của nó để lưu trữ các thông tin truy cập được sử dụng để thực hiện chứng thực. Thực tế, có một số bảng nội bộ được tạo ra như là một phần của tất cả các cài đặt máy chủ MySQL. MySQL sử dụng các bảng cho nhiều mục đích. | DRAFT 8 24 01 21 MySQL System Tables In Chapter XXX Security we saw how MySQL used its own internal tables to store the access information used to perform authentication. There are actually several internal tables that are created as part of every MySQL server installation. MySQL uses these tables for a variety of purposes. Columns_Priv ---------- ------------------------- ---- --------- ---- Field Type Null Key Default Extra ---------- ------------------------- ---- --- ------- ---- Host char 60 binary PRI Db char 64 binary PRI User char 16 binary PRI Table_name char 64 binary PRI Column_name char 64 binary PRI Timestamp timestamp 14 YES NULL Column_priv set Select Insert Update References ----------------- ------------------------------------------ -------- ------- ----------- ---------- The columns_priv table controls column-level access to a MySQL database table. The column-level check is the final check performed in the access verification sequence describe in Chapter XXX Security. The information in this table can be broken into four sections location scope privilege and timestamp. Location These fields determine to whom this privilege applies. Any user who matches both of these fields in a given row will be subjected to the privilege rule for that row. Host - The hostname or IP address of the user. Copyright 2001 O Reilly Associates Inc. 1 DRAFT 8 24 01 User - The authenticated username of the user. Scope These fields determine exactly which column this rule is for. Any columns which match all three of these fields in a given row will have the privilege rule for that row apply. Db - The database that contains the table with the column Table_name - The name of the table containing the column Column_name - The name of the column Privledge The singe privilege column Column_priv determines which privileges are allowed for location and scope defined in the other fields in this table. The value of this column is a set that can contain any of the following .