最近几年来,地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持,如城市管理、区划、环境整治等等,地理信息成为信息时代重要的组成部分之一; “数字地球”概念的提出,更进一步推动了作为其技术支撑的GIS的发展。 与此同时,一些学者致力于相关的理论研究,如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面,并且这两个方面构成了相互促进的发展过程。
Using ordinary users to log in to the MySQL server, you may need specific permissions to create or delete MySQL databases, so we use root users to log in, and root users have the highest permissions.
Be careful when deleting a database, because all data will disappear after the delete command is executed. Drop command format: For example, delete a database named RUNOOB: You can also use it. The following example deletes the database RUNOOB (which was created in the previous section): After executing the above delete database command, a prompt box appears to confirm that the database is actually deleted: PHP usage This function takes two arguments and returns TRUE on successful execution, or FALSE otherwise. Parameters. Description connection Necessary. Specifies the MySQL connection to be used. query Required, specify the query string. resultmode Optional. A constant. It can be any of the following values: MYSQLI_USE_RESULT(如果需要检索大量数据,请使用这个) MYSQLI_STORE_RESULT(默认) The following example demonstrates the use of PHP Delete database After successful execution, the results are as follows: 注意: When using the PHP script to delete the database, there will be no confirmation of whether to delete the information, but will delete the specified database directly, so you should be very careful when deleting the database.Drop command to delete database ¶
drop database <数据库名>;
mysql> drop database RUNOOB;
Delete a database using mysqladmin ¶
mysql mysqladmin The command executes the delete command at the terminal.[root@host]# mysqladmin -u root -p drop RUNOOB Enter password:******
Dropping the database is potentially a very bad thing to do. Any data stored in the database will be destroyed. Do you really want to drop the 'RUNOOB' database [y/N] y Database "RUNOOB" dropped
Use the PHP script to delete the database ¶
mysqli_query Function to create or delete an MySQL database.Grammar ¶
mysqli_query(connection,query,resultmode);
Example ¶
mysqli_query Function to delete the database:';$sql='DROP DATABASE RUNOOB';$retval=mysqli_query($conn,$sql);if(!$retval){die('删除数据库失败:'.mysqli_error($conn));}echo"数据库 RUNOOB 删除成功\\n";mysqli_close($conn);?> 