标签:work rust libs pass existing tst 编程 upd 记录
在本教程将演示如何在JDBC应用程序中向数据库的一个表中插入数据记录。 在执行以下示例之前,请确保您已经准备好以下操作:
username
)和密码(password
)。使用JDBC应用程序向表中插入数据记录需要以下步骤:
导入包:需要包含包含数据库编程所需的JDBC类的包。 大多数情况下,使用import java.sql.*
就足够了。
注册JDBC驱动程序:需要初始化驱动程序,以便可以程序中打开数据库的通信通道。
打开连接:需要使用DriverManager.getConnection()
方法来创建一个Connection
对象,它表示与数据库服务器的物理连接。
执行查询:需要使用类型为Statement
的对象来构建和提交SQL语句,以在选择的数据库的表中插入数据记录。
清理环境:需要明确地关闭所有数据库资源,而不依赖于JVM的垃圾收集。
复制以下示例代码保存到文件:InsertRecords.java中,然后编译并运行如下 -
//STEP 1. Import required packages
// See more detail at http://www.yiibai.com/jdbc/
import java.sql.*;
public class InsertRecords {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/jdbc_db";
// Database credentials
static final String USER = "root";
static final String PASS = "123456";
public static void main(String[] args) {
Connection conn = null;
Statement stmt = null;
try{
//STEP 2: Register JDBC driver
Class.forName("com.mysql.jdbc.Driver");
//STEP 3: Open a connection
System.out.println("Connecting to a selected database...");
conn = DriverManager.getConnection(DB_URL, USER, PASS);
System.out.println("Connected database successfully...");
//STEP 4: Execute a query
System.out.println("Inserting records into the table...");
stmt = conn.createStatement();
String sql = "INSERT INTO student " +
"VALUES (100, ‘C++‘, ‘Li‘, 18)";
stmt.executeUpdate(sql);
sql = "INSERT INTO student " +
"VALUES (101, ‘Python‘, ‘Py‘, 25)";
stmt.executeUpdate(sql);
sql = "INSERT INTO student " +
"VALUES (102, ‘Ruby‘, ‘Ru‘, 30)";
stmt.executeUpdate(sql);
sql = "INSERT INTO student " +
"VALUES(103, ‘Java‘, ‘Ja‘, 28)";
stmt.executeUpdate(sql);
System.out.println("Inserted records into the table...");
}catch(SQLException se){
//Handle errors for JDBC
se.printStackTrace();
}catch(Exception e){
//Handle errors for Class.forName
e.printStackTrace();
}finally{
//finally block used to close resources
try{
if(stmt!=null)
conn.close();
}catch(SQLException se){
}// do nothing
try{
if(conn!=null)
conn.close();
}catch(SQLException se){
se.printStackTrace();
}//end finally try
}//end try
System.out.println("Goodbye!");
}//end main
}//end JDBCExample
编译上面代码,如下 -
F:\worksp\jdbc> javac -Djava.ext.dirs=F:\worksp\jdbc\libs InsertRecords.java
执行上面代码,如下 -
## 可先创建表 -
## F:\worksp\jdbc> java -Djava.ext.dirs=F:\worksp\jdbc\libs CreateTable
F:\worksp\jdbc>java -Djava.ext.dirs=F:\worksp\jdbc\libs InsertRecords
Connecting to a selected database...
Thu Jun 01 22:51:41 CST 2017 WARN: Establishing SSL connection without server‘s identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn‘t set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to ‘false‘. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Connected database successfully...
Inserting records into the table...
Inserted records into the table...
Goodbye!
F:\worksp\jdbc>
在执行上面语句后,查询 student
表中的数据如下 -
mysql> select * from student;
+-----+--------+------+-----+
| id | first | last | age |
+-----+--------+------+-----+
| 100 | C++ | Li | 18 |
| 101 | Python | Py | 25 |
| 102 | Ruby | Ru | 30 |
| 103 | Java | Ja | 28 |
+-----+--------+------+-----+
4 rows in set
mysql>
标签:work rust libs pass existing tst 编程 upd 记录
原文地址:https://www.cnblogs.com/borter/p/9608826.html