tailieunhanh - MySQL Administrator's Bible- P8

MySQL Administrator's Bible- P8: Với tập trung đặc biệt vào việc phát hành lớn tiếp theo của MySQL, nguồn tài nguyên này cung cấp một khuôn khổ vững chắc cho bất cứ ai mới vào MySQL hoặc chuyển từ một nền tảng cơ sở dữ liệu, cũng như các quản trị MySQL kinh nghiệm. Các bộ đôi tác giả cao hồ sơ cung cấp bảo hiểm thiết yếu của các nguyên tắc cơ bản của phạm vi bảo hiểm cơ sở dữ liệu quản lý, bao gồm cả cách tiếp cận độc đáo MySQL của các tính năng cơ sở. | MySQL Views 8 Note that updating the view presents a logical error. Even if Benjamin had privileges to the base tables updating the view would generate no warning or error but produces incorrect results. Changing a View Definition There are two ways to change a view. One method has already been discussed using the CREATE OR REPLACE when defining a view. In addition MySQL has an ALTER VIEW command. ALTER VIEW works much like ALTER TABLE. The SELECT statement that defines the view must always be included in the ALTER VIEW statement even if that part of the view definition is not being modified. You may have noticed that in the CREATE VIEW statement four different clauses may come between the words CREATE and VIEW CREATE OR REPLACE ALGORITHM UNDEFINED MERGE TEMPTABLE DEFINER user CURRENT_USER SQL SECURITY DEFINER INVOKER VIEW view_name column_list AS select_statement WITH CASCADED LOCAL CHECK OPTION Similarly the syntax of the ALTER VIEW statement is ALTER ALGORITHM UNDEFINED MERGE TEMPTABLE DEFINER user CURRENT_USER SQL SECURITY DEFINER INVOKER VIEW view_name column_list AS select_statement WITH CASCADED LOCAL CHECK OPTION Only the view s definer or a user with the SUPER privilege can ALTER a view. Replication and Views In both row- and statement-based replication MySQL treats a view the same way it treats a base table. In statement-based replication CREATE VIEW ALTER VIEW and DROP VIEW statements are written to the binary log and thus replicated. In row-based replication the underlying data is replicated. The replicate-do-table and replicate-ignore-table replication options are applied to views and tables in both statement- and row-based replication with the following outcomes 317 Part II Developing with MySQL A view that matches a replicate-do-table pattern will be written to the binary log and thus replicated. A view that matches a replicate-ignore-table pattern will not be written to the binary log and thus not be replicated. replicate-do-table and .