Tài liệu MySQL Administrator''''s Bible- P3 docx

Accessing MySQL 3 the server host and the mysqld instance. If you experience any problems SQLyog has very thor- ough, context-sensitive help. Figure 3-1 shows this connection dialog. FIGURE 3-1 SQL query creation SQLyog has two methods of SQL query creation. With the first method you type the query in a query building window. SQLyog provides two tools to assist you — the auto-completion feature and SQL templates. mysql does not have tab completion on Windows (see the previous section on mysql features). With SQLyog you can use the Tab key to complete table or column names or even functions, no matter what operating system you are using. SQL templates help with the proper syntax for the various SQL commands. First, right-click in the query building window. This will bring up a menu where you left-click Insert Templates to use a template. Figure 3-2 shows the list of available templates with the CREATE TRIGGER statement template selected. At this point you just click the Insert button and SQLyog will create the template for you to fill in with your specific data. The second method of query writing is using the query builder to create the query. This is a more graphical method of query building where you drag the appropriate tables from the schema objects to a blank window. You can then do the common query actions of joining tables, sorting, filtering, and grouping based on your chosen criteria. SQLyog will then build the SQL command for you to execute without actually having to type any SQL code. Figure 3-3 shows how the query builder looks with a simple query built from the sakila database. 67 Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Part I First Steps with MySQL FIGURE 3-2 FIGURE 3-3 68 Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Accessing MySQL 3 After building the query you can copy the query over to the Query tab and then execute it with just a couple of clicks. Database management SQLyog has numerous features designed for database management. Among the tasks you can perform are: ■ Create new tables ■ Manage table indexes ■ Manage users ■ Synchronize databases ■ Back up and restore databases ■ Create triggers, views, events, and stored procedures Database synchronization One of the best features of SQLyog is the database synchronization with its powertool. This tool allows you to synchronize two different databases by creating the corresponding SQL commands needed to match both the structure and data of the two database tables. There is a wizard that will guide through each step of the process. The process is simple — just select the databases and tables to synchronize and SQLyog takes care of everything else. Resolving a data synchro- nization problem by hand is incredibly difficult, and SQLyog reduces the complexity to a few simple clicks. phpMyAdmin phpMyAdmin is a free set of PHP scripts that are used to manage a MySQL server via a web interface. Because phpMyAdmin is based on these PHP scripts it does require a web server to run. Though this might be seen as a drawback, it also means that you can access your MySQL servers from any computer that has a web browser. phpMyAdmin can be used to manage an entire MySQL server or a single database. You can find more information about phpMyAdmin, including how to download the program, at http://www.phpmyadmin.net/. We are not going to show how to install phpMyAdmin for your server setup because it varies depending on your operating system. Typically, it is not very difficult. Once done with the installation of phpMyAdmin, access the system by simply going to the following URL in your browser: http://yourserverip/phpmyadmin. You will need to replace yourserverip with the hostname or IP address of your web server. You will be presented with a login screen where you will input your MySQL server login credentials. 69 Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Part I First Steps with MySQL Figure 3-4 shows the opening screen for phpMyAdmin once you log in. FIGURE 3-4 You will use the left-hand frame in phpMyAdmin for navigation. Initially you will see the databases on the server displayed in this area. Tables will also be displayed under each database as they are created. In addition to the database navigation area on the left side, a number of options are available on the right-hand side of the split screen. Creating a database If you need to create a database there is a Create Database option on the main screen. You sim- ply enter the new database name and click the Create button. Creating a table in your database Creating a table is almost as easy as creating a database. Just click the database you created in the navigation frame and a new window will appear on the right-hand side of the split screen. To create a table you just use the Create New Table option. You should enter the name of the new table into the Name field, and the number of expected fields for the table into Fields. At this point, after you click Go, you just fill in the information for the columns in your new table. Once you are done with configuration, clicking the Save button will create your new table. 70 Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Accessing MySQL 3 Data insertion into a table Once your table is configured you can fill it with data using phpMyAdmin. On the screen that is displayed after you create a table there is an Insert tab. Click this and another screen should appear. This screen is your data entry screen. When you are done with a record just click Save and it will be saved to the table. After you click Save, the record is saved to the testing table, and the data entry screen is shown again. You can insert more records by selecting Insert again. If you are going to be inserting multiple records it is faster if you select the Insert Another New Row radio button on the input form. Database backup Backing up databases is easy with phpMyAdmin. You select the database you want to back up by clicking the database name in the left-hand navigation bar. Next you click the Export button and then make sure all tables are highlighted that you want to back up. You can then specify the options you want under Export. Make sure that you enter a filename so you can save the output. In the background phpMyAdmin is using the mysqldump program, which is covered in Chapter 13. The phpMyAdmin program has a fairly user-friendly interface. Because it is used by a number of web-hosting providers, many administrators are at least somewhat familiar with it. Although it has a modest range of abilities, it does have some flexibility in that you can access the program from anywhere with a web browser. It should be pointed out, as we discuss in Chapter 20, that running both a web server and a database server on the same server increases your security risk. Sharing resources means there will be fewer available for mysqld. Think very carefully before installing phpMyAdmin on the same machine as mysqld. MySQL Query Browser The Query Browser is part of the GUI bundle that MySQL has available for free download from http://dev.mysql.com/downloads/gui-tools. Also included in this bundle are the MySQL Administrator tool (discussed in the following section) and the MySQL Migration Tool, which we will not be covering. The Query Browser and other associated tools are available for Windows, Macintosh OS X, and Linux so it allows for a good degree of cross-platform usage. The Query Browser is a GUI tool for creating, executing, and optimizing queries. The Query Browser includes the following components: ■ Query Toolbar: Create small queries and execute them. Browse old queries. ■ Script Editor: Useful for editing more complex queries. 71 Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Part I First Steps with MySQL ■ Results Window: Displays query results. ■ Database Explorer: Navigate, create, and drop tables and fields. The central interface of the Query Browser provides access to all of the preceding functionality. This window is also customizable by allowing you to control which toolbars are present. The Query History functionality combined with navigation buttons allows you to browse your query history and re-execute queries with or without editing them. To begin a Query Browser session you have to establish a connection to your server. When you start Query Browser you see the screen in Figure 3-5. FIGURE 3-5 One of the biggest shortcomings of Query Browser is that it does not allow for the direct con- nection to a server using an ssh session. In many organizations, administrator access to mysqld is restricted to connecting only from the local server. In order to use Query Browser you must establish an ssh tunnel manually, which can be a tricky operation. It is also frustrating to have to set up an ssh tunnel every time you want to use MySQL Query Browser. In contrast, the pre- viously discussed SQLyog program allows direct secure connections using ssh tunneling very easily. Once you have established your connection to the server you are presented with the main Query Browser screen, which is shown in Figure 3-6. Looking on the right-hand side of the screen you can see the databases on the connected server. In this case you can see the information_schema and mysql databases (used by the MySQL server) and a test database. Also there is the sakila database, which you will be using for the example. 72 Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Accessing MySQL 3 FIGURE 3-6 To work with the sakila database a single mouse-click on the arrow to the left of the sakila database icon will display all the tables. Just enter the query to execute and click the Execute button to the right of query entry screen. Once you enter the query and execute it the results are shown in the results pane on the bottom left of the screen, as shown in Figure 3-7. After you have entered multiple queries you can use the Go Back and Next buttons to browse through the history of the already executed queries. Under the Tools menu you can start MySQL Administrator, the mysql command-line client, the Windows command line (if you are on Windows), a text importer (that uses regular expressions), and the connections manager, where you can save connection information. You can also manage stored routines very easily with Query Browser. This might be one of the best features of Query Browser because it is very difficult to manage a stored routine from the MySQL command line (see Chapter 7 for more information about stored routines). Though a procedure or function can be programmed from the command line, it is awkward at best. A graphical environment such as Query Browser makes it much easier to work with stored procedures and functions. 73 Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Part I First Steps with MySQL FIGURE 3-7 To begin a new stored procedure, make sure you have a database selected and then just click Script and then Create Stored Procedure/Function. Once you have created the stored procedure or function you will be presented with the editing screen as shown in Figure 3-8. All of the initial setup is already done for you. Just write your query and click the Execute but- ton to store it on the server. You can also examine and edit stored procedures and functions that are already created. To do this just click Script on the menu bar and select Edit All Stored Pro- cedures/Functions. Figure 3-9 shows what this looks like. Now you just edit the appropriate procedure and click Execute to reload the procedures. The Query Browser program is well rounded with only one major weakness: Though it is more specialized than the other programs covered here, it is designed to work in tandem with the MySQL Administrator program covered in the next section. MySQL Administrator The MySQL Administrator is included in the same bundle with the Query Browser. It is a cross-platform tool that runs on Windows, Linux, and the Mac OS X. MySQL Administrator is a GUI console that enables you to administer a mysqld server instance. 74 Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Accessing MySQL 3 FIGURE 3-8 FIGURE 3-9 75 Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Part I First Steps with MySQL Some of the functionality that MySQL Administrator allows includes: ■ User management ■ Monitoring database health ■ Performing backups and restores ■ Managing server logs ■ Monitoring server connections The connection dialog is the same as for Query Brower. Once you have established your connec- tion to a server the main screen will look similar to what is shown in Figure 3-10. FIGURE 3-10 This is the central control panel used to manage your servers. On the left-hand panel you can see the icons that are used to access the screens for specific functions. 76 Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. [...]... tool ■ The mysqlshow tool Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark 83 3 Part I First Steps with MySQL ■ GUI tools for MySQL administration including: ■ SQLyog ■ phpMyAdmin ■ MySQL Query Browser ■ MySQL Administrator ■ MySQL Workbench 84 Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark Developing with MySQL IN THIS PART Chapter 4 How MySQL Extends... Extends and Deviates From Standard SQL Chapter 5 MySQL Data Types Chapter 6 MySQL Index Types Chapter 7 Stored Routines, Triggers, and Events Chapter 8 MySQL Views Chapter 9 Transactions in MySQL Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark How MySQL Extends and Deviates from SQL M ySQL was originally... the sakila database is: IN THIS CHAPTER Learning MySQL language Structure Understanding MySQL deviations Using MySQL extensions SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA=’sakila’; The easiest way to find out this information in MySQL is: SHOW TABLES FROM sakila; Most of the differences from standard SQL and SQL extensions in MySQL come from the desire to make the database system... — these are actually translated into other commands by the mysql command line client However, mysqld has actual escape sequences, which are independent of the mysql commands Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark 91 4 Part II Developing with MySQL These escape sequences are used only within strings (the mysql ones are not within strings) and are parsed unless the... There is no conversion that takes place during an upgrade from MySQL 5.1 to MySQL 6.0 Therefore, to use a true implementation of Unicode, MySQL must be upgraded to version 6.0 or higher, and an explicit conversion must be done of all fields using utf8mb3 For more information about this type of upgrade, see the MySQL manual at http://dev .mysql. com/doc/refman/6.0/en/charset-unicode-upgrading.html Identifiers... your MySQL server version for the right syntax to use near ’from DATE)’ at line 1 mysql> CREATE TABLE `name.test`(date DATE); Query OK, 0 rows affected (0.37 sec) mysql> SELECT COUNT(*) FROM dot.test; ERROR 1146 (42S02): Table ’dot.test’ doesn’t exist mysql> SELECT COUNT(*) FROM test.dot.test; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL. .. allow 88 Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark How MySQL Extends and Deviates from SQL partial line and multi-line commenting Putting ! after the bracketed comment introducer indicates that this is MySQL specific code, and the mysqld server will parse it: /*! SHOW DATABASES */; The mysqld server will parse the SHOW DATABASES statement, but other database systems will... SQL_NOTES=0 */; This means that mysqld versions 4.1.1 and higher will apply the first statement, and mysqld versions 4.1.11 and higher will apply the last statement A comment that will only be applied to mysqld versions 6.0.8 and higher begins with /*!60008 While this syntax makes the code portable, it does not guarantee that the code will work as expected For example, mysqldump exports tables in alphabetical... meaning that SELECT, select, and SeLeCt are all parsed by mysqld as the same reserved word Throughout this book, we will format reserved words in uppercase, even though mysqld will properly parse reserved words regardless of case In general, mysqld is case-insensitive with respect to names of fields, indexes, stored routines and events However, mysqld stores information on the file system and makes assumptions... is the stronger of the two related programs Both programs are available from http://dev .mysql. com/downloads/gui-tools MySQL Workbench MySQL Workbench is a visual data modeling and database design tool Schema creation and change scripts can be automatically created from the database designs There are two versions of MySQL Workbench: an open source Community Edition and a commercial Standard Edition (SE) . First Steps with MySQL ■ GUI tools for MySQL administration including: ■ SQLyog ■ phpMyAdmin ■ MySQL Query Browser ■ MySQL Administrator ■ MySQL Workbench 84 Please. watermark. Developing with MySQL IN THIS PART Chapter 4 How MySQL Extends and Deviates From Standard SQL Chapter 5 MySQL Data Types Chapter 6 MySQL Index Types Chapter