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1 software environment Oracle Linux 6.9 Oracle 12.1.0.2 Main library: sz.oracle.com ，IP: 192.168.1.102 Standby: sh.oracle.com ，IP: 192.168.1.103 2 main database configuration 2.1 check and set up database 1) First, the primary database must be running in Force Logging mode, which is to prevent direct data modification without logging ...

How to Building physical standby database by RMAN Duplicate , this article will demonstrate how to use Cloud Control to build a physical standby database. 1 software environment Oracle Linux 6.9 Oracle 12.1.0.2 Oracle Enterprise Management Cloud Control 12.1.0.4 Main library: odd.oracle.com ，IP: 192.168.1.105 Standby: even.oracle.com ， ...

Constraints on database tables 1. An overview of Database Constraints 1.1 Role of constraints: Restrict the data in the table to ensure the correctness, validity and integrity of the data.If a table has constraints added, incorrect data cannot be inserted into the table.Constraints are appropriate to add when creating tables. 1.2 Constraint ...

Using PDO constructor to connect database and DSN <?php $dbms = 'mysql'; $dbname = 'test'; $user = 'root'; $pwd = '123456'; $host = 'localhost'; $dsn = "$dbms:host=$host;dbName=$dbname"; try{ $pdo = new PDO($dsn,$user,$pwd); echo 'pdo Successfully connected to database'; }catch(Exception $e){ echo $e->getMessage().'<br&gt ...

There is a lot of feedback from readers. Please refer to the previous article< Hive is finally waiting, Flink >When Flink is deployed and Hive is integrated, there are some bug s and compatibility problems. Although waiting, it is not available. So I added this article as a sister article. review In the previous article, the author use ...

php connects to mysql database Five steps for PHP to access MYSQL database 1. Connect to MySQL database Using MySQL_ The connect() function establishes a connection to the MySQL server. 2. Select MySQL database Using MySQL_ select_ The db() function selects the database of the MySQL database server. 3. Execute SQL statement Using MySQL in the s ...

The tests are as follows: (1) Create two tables and insert data. The sql statement is as follows: a table: CREATE TABLE `a` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(50) DEFAULT '', `grade` int(11) DEFAULT NULL, `dept` int(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB CHARSET=utf8mb4 insert into `a` ...

Verification details of php forms First of all, we process all the data submitted by the user through the htmlspecialchars() function of PHP. Converts special characters to HTML entities. This means that HTML characters such as < and > are replaced with & lt; and & gt. This prevents attackers from injecting HTML or JavaScript Code ...

0. Preface We have a general understanding of SqlSugar in the last and last articles, but this is not perfect, because those are theoretical knowledge, unable to describe the actual situation in our engineering development. In this article, I will lead my friends to try to write a template class that can be used in the project. 1. Create a Clie ...

0. Preface In the last article, we know how to use SqlSugar, but we just know how to use it, as if walking in chains, which obviously does not meet the quality of a qualified programmer. Therefore, in this article, we will dig deep into it and explore the secrets behind it. 1. Fancy mapping In the actual development, the entity class in the pro ...