JDBC示例（增删查改）
前提：
1、项目中引入MySQL的JAR包，POM参考如下配置：
<!-- mysql-connector-java -->
<!-- http://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.38</version>
</dependency>
示例：
一、创建数据库
//STEP 1. Import required packages
import java.sql.*; public class JDBCExample {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/"; // Database credentials
static final String USER = "root";
static final String PASS = "root"; 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 database...");
conn = DriverManager.getConnection(DB_URL, USER, PASS); // STEP 4: Execute a query
System.out.println("Creating database...");
stmt = conn.createStatement(); String sql = "CREATE DATABASE STUDENTS";
stmt.executeUpdate(sql);
System.out.println("Database created successfully...");
} 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)
stmt.close();
} catch (SQLException se2) {
} // nothing we can do
try {
if (conn != null)
conn.close();
} catch (SQLException se) {
se.printStackTrace();
} // end finally try
} // end try
System.out.println("Goodbye!");
}// end main
}// end JDBCExample
这将产生如下所示结果：
二、选择数据库
//STEP 1. Import required packages
import java.sql.*; public class JDBCExample2 {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/STUDENTS?serverTimezone=UTC"; // Database credentials
static final String USER = "root";
static final String PASS = "root"; public static void main(String[] args) {
Connection conn = 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...");
} 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 (conn != null)
conn.close();
} catch (SQLException se) {
se.printStackTrace();
} // end finally try
} // end try
System.out.println("Goodbye!");
}// end main
}// end JDBCExample
这将产生如下所示结果：
三、删除数据库
//STEP 1. Import required packages
import java.sql.*; public class JDBCExample3 {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/"; // Database credentials
static final String USER = "root";
static final String PASS = "root"; 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("Deleting database...");
stmt = conn.createStatement(); String sql = "DROP DATABASE STUDENTS";
stmt.executeUpdate(sql);
System.out.println("Database deleted successfully...");
} 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
这将产生如下所示结果：
四、创建表
//STEP 1. Import required packages
import java.sql.*; public class JDBCExample4 {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/STUDENTS?serverTimezone=UTC"; // Database credentials
static final String USER = "root";
static final String PASS = "root"; 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("Creating table in given database...");
stmt = conn.createStatement(); String sql = "CREATE TABLE REGISTRATION " + "(id INTEGER not NULL, " + " first VARCHAR(255), "
+ " last VARCHAR(255), " + " age INTEGER, " + " PRIMARY KEY ( id ))"; stmt.executeUpdate(sql);
System.out.println("Created table in given database...");
} 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
这将产生如下所示结果：
五、删除表
//STEP 1. Import required packages
import java.sql.*; public class JDBCExample5 {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/STUDENTS?serverTimezone=UTC"; // Database credentials
static final String USER = "root";
static final String PASS = "root"; 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("Deleting table in given database...");
stmt = conn.createStatement(); String sql = "DROP TABLE REGISTRATION "; stmt.executeUpdate(sql);
System.out.println("Table deleted in given database...");
} 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
这将产生如下所示结果：
六、插入记录
//STEP 1. Import required packages
import java.sql.*; public class JDBCExample6 {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/STUDENTS?serverTimezone=UTC"; // Database credentials
static final String USER = "root";
static final String PASS = "root"; 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 Registration " + "VALUES (100, 'Zara', 'Ali', 18)";
stmt.executeUpdate(sql);
sql = "INSERT INTO Registration " + "VALUES (101, 'Mahnaz', 'Fatma', 25)";
stmt.executeUpdate(sql);
sql = "INSERT INTO Registration " + "VALUES (102, 'Zaid', 'Khan', 30)";
stmt.executeUpdate(sql);
sql = "INSERT INTO Registration " + "VALUES(103, 'Sumit', 'Mittal', 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
这将产生如下所示结果：
七、查询表记录
//STEP 1. Import required packages
import java.sql.*; public class JDBCExample7 {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/STUDENTS?serverTimezone=UTC"; // Database credentials
static final String USER = "root";
static final String PASS = "root"; 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("Creating statement...");
stmt = conn.createStatement(); String sql = "SELECT id, first, last, age FROM Registration";
ResultSet rs = stmt.executeQuery(sql);
// STEP 5: Extract data from result set
while (rs.next()) {
// Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last"); // Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
}
rs.close();
} 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
这将产生如下所示结果：
八、更新表记录
//STEP 1. Import required packages
import java.sql.*; public class JDBCExample8 {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/STUDENTS?serverTimezone=UTC"; // Database credentials
static final String USER = "root";
static final String PASS = "root"; 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("Creating statement...");
stmt = conn.createStatement();
String sql = "UPDATE Registration " + "SET age = 30 WHERE id in (100, 101)";
stmt.executeUpdate(sql); // Now you can extract all the records
// to see the updated records
sql = "SELECT id, first, last, age FROM Registration";
ResultSet rs = stmt.executeQuery(sql); while (rs.next()) {
// Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last"); // Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
}
rs.close();
} 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
这将产生如下所示结果：
九、删除记录
//STEP 1. Import required packages
import java.sql.*; public class JDBCExample9 {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/STUDENTS?serverTimezone=UTC"; // Database credentials
static final String USER = "root";
static final String PASS = "root"; 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("Creating statement...");
stmt = conn.createStatement();
String sql = "DELETE FROM Registration " + "WHERE id = 101";
stmt.executeUpdate(sql); // Now you can extract all the records
// to see the remaining records
sql = "SELECT id, first, last, age FROM Registration";
ResultSet rs = stmt.executeQuery(sql); while (rs.next()) {
// Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last"); // Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
}
rs.close();
} 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
这将产生如下所示结果：
十、Where子句
//STEP 1. Import required packages
import java.sql.*; public class JDBCExample10 {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/STUDENTS?serverTimezone=UTC"; // Database credentials
static final String USER = "root";
static final String PASS = "root"; 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("Creating statement...");
stmt = conn.createStatement(); // Extract records without any condition.
System.out.println("Fetching records without condition...");
String sql = "SELECT id, first, last, age FROM Registration";
ResultSet rs = stmt.executeQuery(sql); while (rs.next()) {
// Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last"); // Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
} // Select all records having ID equal or greater than 101
System.out.println("Fetching records with condition...");
sql = "SELECT id, first, last, age FROM Registration" + " WHERE id >= 101 ";
rs = stmt.executeQuery(sql); while (rs.next()) {
// Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last"); // Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
}
rs.close();
} 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
这将产生如下所示结果：
十一、Like子句
//STEP 1. Import required packages
import java.sql.*; public class JDBCExample11 {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/STUDENTS?serverTimezone=UTC"; // Database credentials
static final String USER = "root";
static final String PASS = "root"; 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("Creating statement...");
stmt = conn.createStatement(); // Extract records without any condition.
System.out.println("Fetching records without condition...");
String sql = "SELECT id, first, last, age FROM Registration";
ResultSet rs = stmt.executeQuery(sql); while (rs.next()) {
// Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last"); // Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
} // Select all records having ID equal or greater than 101
System.out.println("Fetching records with condition...");
sql = "SELECT id, first, last, age FROM Registration" + " WHERE first LIKE '%za%' ";
rs = stmt.executeQuery(sql); while (rs.next()) {
// Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last"); // Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
}
rs.close();
} 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
这将产生如下所示结果：
十二、排序
//STEP 1. Import required packages
import java.sql.*; public class JDBCExample12 {
// JDBC driver name and database URL
static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://localhost/STUDENTS?serverTimezone=UTC"; // Database credentials
static final String USER = "root";
static final String PASS = "root"; 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("Creating statement...");
stmt = conn.createStatement(); // Extract records in ascending order by first name.
System.out.println("Fetching records in ascending order...");
String sql = "SELECT id, first, last, age FROM Registration" + " ORDER BY first ASC";
ResultSet rs = stmt.executeQuery(sql); while (rs.next()) {
// Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last"); // Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
} // Extract records in descending order by first name.
System.out.println("Fetching records in descending order...");
sql = "SELECT id, first, last, age FROM Registration" + " ORDER BY first DESC";
rs = stmt.executeQuery(sql); while (rs.next()) {
// Retrieve by column name
int id = rs.getInt("id");
int age = rs.getInt("age");
String first = rs.getString("first");
String last = rs.getString("last"); // Display values
System.out.print("ID: " + id);
System.out.print(", Age: " + age);
System.out.print(", First: " + first);
System.out.println(", Last: " + last);
}
rs.close();
} 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
这将产生如下所示结果：
测试工程：https://github.com/easonjim/5_java_example/tree/master/jdbcbasics/test10/
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