... nó cũng được sử
dụng 1 cách đặc biệt. Để làm việc với NULL, chúng ta không sửdụng các toán
tử so sánh thông thường như <, >, <>, =. Để hiểu rõ, xin thử như sau:
mysql& gt; select ... Bạn mở tập tin
pet.txt ra, sửa lại record bạn muốn sửa. Rồi đánh lệnh sau:
mysql& gt; set autocommit=1; #dùng để tạo nhanh lại 1 bảng.
mysql& gt; delete from pet;
mysql& gt; load data infile ... f | 1989-05-13 | NULL |
+ + + + + + +
Ngoài ra, mysql còn sửdụng "extended regular expresions" cho pattern
matching. Khi sửdụng kiểu này, bạn thay LIKE và NOT LIKE thành REGEXP...
... and
support of MySQL. MySQL AB is a Swedish company run by MySQL s core devel-
opers. MySQL AB owns the copyright to MySQL as well as the trademark MySQL .
Since the initial Internet release of MySQL, ... and contents of a MySQL database or table to a file.
mysqlhotcopy
Performs a hot backup of a MySQL database.
mysqlimport
Imports data in different file formats into a MySQL table
mysqlshow
Shows ... in a file.
mysqlaccess
Manages users.
mysqladmin
Enables you to manage the database server, including the creation and dele-
tion of databases.
mysqld
The actual MySQL server process.
mysqldump
Dumps...
... one
popular database product: MySQL. We start by introducing you to relational databases
and MySQL. We then proceed to show you how to get up and running with MySQL and
how to administer it. ... get up and running with MySQL and
how to administer it. The rest of the book covers the use of MySQL to design, build and
support the type of applications important to users like you.
What ... database can be formatted by your program into a new
HTML page to send back to the user.
Summary
MySQL is an SQL-based Relational Database Management System (RDMS). Relational
databases are organized...
... /usr/local /mysql
$ chgrp –R mysql /usr/local /mysql
Set the ownership of the data directories to the MySQL administrative user you created
earlier (for this example, mysql) .
$ chown –R mysql /usr/local /mysql/ data ... software
MySQL- client-<VERSION>.i386.rpm
The MySQL client software
MySQL- bench-<VERSION>.i386.rpm
MySQL tests and benchmarks. This
requires the perl and msql -mysql-
modules RPMs.
MySQL- devel-<VERSION>.i386.rpm ... /usr/local /mysql
$ chgrp –R mysql /usr/local /mysql
Set the ownership of the data directories to the MySQL administrative user you created
earlier (for this example, mysql) .
$ chown –R mysql /usr/local /mysql/ data...
... following tables already exist:
mysql& gt; SHOW DATABASES;
+ +
| Database |
+ +
| mysql |
| test |
+ +
2 rows in set (0.37 sec)
mysql& gt;
The first database, mysql, is MySQL s system database. You ... Commands end with ; or \g.
Your MySQL connection id is 3 to server version: 3.22.29
Type 'help' for help.
mysql& gt;
The mysql command above says to connect to the MySQL server on the local
machine ... primary goals.
Chapter 17, MySQL Data Types, provides a full reference of SQL types supported
by MySQL. Table 4-1 is an abbreviated listing of the most common types.
MySQL supports the UNSIGNED...
... Associates, Inc.
8
$ ls -l
.
.
-rw-rw 1 mysqlmysql 203 Aug 5 17:45 odin-bin.001
-rw-rw 1 mysqlmysql 73 Aug 5 17:45 odin-bin.002
-rw-rw 1 mysqlmysql 30 Aug 5 17:45 odin-bin.index
.
. ... information.
$ mysql
mysql& gt; use test
.
.
mysql& gt; insert into test (object_id, object_title) values (1, "test");
Query OK, 1 row affected (0.02 sec)
mysql& gt; quit
Bye
$ mysqlbinlog ... UNIX system, you can use safe_mysqld to automatically start
MySQL at boot. safe_mysqld is found in the bin directory of your MySQL
installation (usually /usr/local /mysql/ bin).
DRAFT, 8/17/01...
... this approach is that MySQL has the overhead of parsing,
optimizing and executing the same query multiple times. If you let MySQL retrieve
all the rows at once, you let MySQL do what it is good ... sec)
This tells us that MySQL will scan all rows in the MySQL table to satisfy the query. This
is indicated by the join type of “ALL”. The rows column tells us that MySQL estimates it
will ... modified in the MySQL server which may
improve your performance. A full reference on these parameters can be found in Chapter
20, or by typing mysqld –help.
In general, when tuning MySQL, the two...
... rest
of the MySQL installation
• The MySQL server should run as a special user and group
Since any user who has access to the MySQL data files has access to the MySQL data, the
MySQL server ... user, created just for MySQL. The default
MySQL installation does this by creating a mysql user and a mysql group. This user
and this group have full access to the MySQL data and should ... any files containing data used by MySQL must be inaccessible by a normal
user. However, we cannot simply make all MySQL- related files forbidden. Most of the
MySQL files, such as the executable...
... is an example SQL script for creating the example database in MySQL.
Example 2-1: An Example Script for Creating the CD Database in MySQL
CREATE TABLE CD (CD_ID INT NOT NULL,
RECORD_LABEL_ID ... the “FOREIGN KEY” reference is not used in the script. This is because
MySQL does not support FOREIGN KEY constraints. MySQL will allow you to embed
them in your CREATE TABLE statements but ... up with a MySQL database where you can store data. How
do you get there? Physical database design translates your logical data model into a set of
SQL statements that define your MySQL database....
... recently, MySQL had no support for transactions. In other words, when you
executed a SQL statement under old versions of MySQL, it took effect immedi-
ately. This behavior is still the default for MySQL. ... to
this question.
Under MySQL, the right answer currently is to put the processing in the client due
to the lack of stored procedure support in MySQL. Stored procedures are on the
MySQL to-do list, ... in the later chapters of this section, MySQL exposes itself through
a variety of APIs tailored to specific programming languages. Java applications
access MySQL through JDBC; Python applications...
... database servers.
The database-specific functionality for MySQL is placed in a utility class called simply
&apos ;mysql& apos;.
package BM: :mysql;
use strict;
use warnings;
sub new {
my ... returned as ANSI SQL standard types. While these are often the same as the
MySQL data types, many of the more unusual MySQL data types (such as
NUMERIC, and TEXT) are represented as simpler ANSI ... case, we have a driver object created from the DBD MySQL
module. Through the 'func' method on this object, we are able to call the MySQL- specific
'ListDBs' function and retrieve...
... the
format you wish to use by setting MySQLdb.paramstyle. The above example is
MySQLdb.paramstyle = "format". The "format" value is the default for
MySQLdb when a tuple of parameters ... will be some instances, however, where you may
need access to MySQL- specific functionality.MySQLdb is actually built on top of
the MySQL C API, and it exposes that API to programs that wish to ... chapter, you will need to download and
install the MySQLdb, the MySQL version of DB-API. You can find the module at
http://dustman.net/andy/python/MySQLdb. Chapter 23, The Python DB-API in the
reference...
... com.caucho.jdbc .mysql.
Driver
jdbc :mysql- caucho://HOST[:PORT]/DB
GNU org.gjt.mm .mysql. Driver jdbc :mysql: //[HOST][:PORT]/
DB[?PROP1=VAL1][&PROP2=VAL2]
twz twz1.jdbc .mysql. jdbc-
MysqlDriver
jdbc:z 1MySQL: //HOST[:PORT]/
DB[?PROP1=VAL1][&PROP2=VAL2] ... available for MySQL. Of
course, you are also able to use any sort of ODBC bridge to talk to MySQL as
well—but we do not recommend it under any circumstance for MySQL develop-
ers.
Of the three MySQL ... protocol for the
Caucho MySQL driver, for example, is mysql- caucho while the GNU driver uses
mysql. The subprotocol provides the implementation-specific connection data. All
MySQL drivers require...
... three. This is equivalent to
running the mysqladmin drop utility. As with running mysqladmin, you must be
the administrative user for MySQL (usually root or mysql) to perform this state-
DRAFT, 8/24/01
Copyright ... large SELECT query is encountered. If set to
1, MySQL will abort the query with an error if the query would probably take
too long to compute. MySQL decides that a query will take too long it ... backslash followed by another character to indicate
to MySQL that the second character has a meaning other than its normal
meaning. Table 16-1 shows the MySQL escape sequences. Quotes can also be
escaped...