JDBC数据库

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1、jdbc java database connection
导包：
web工程：直接复制jar包到WEB-INF/lib下
java工程：新建lib文件夹，放置jar包；
build path--》Libraries -》Add jars
案例一： // 1. 加载驱动
Class.forName("org.sqlite.JDBC");
// 2.创建数据库的连接
Connection conn = DriverManager
.getConnection("jdbc:sqlite:/c:/db1522.db");
// 3.创建执行sql语句的Statement
Statement stmt = conn.createStatement();

// 4.执行查询操作,返回结果集
String sql = "select * from student";
ResultSet rs = stmt.executeQuery(sql);

while (rs.next()) {
System.out.println(rs.getInt(1) + "," + rs.getStrin("name"));
}
案例二：数据的增删改： // 1. 加载驱动
Class.forName("org.sqlite.JDBC");
// 2.创建数据库的连接
Connection conn = DriverManager
.getConnection("jdbc:sqlite:/c:/db1522.db");

// 3.创建执行sql语句的Statement
Statement stmt = conn.createStatement();

// insert
String name = "tom";
String sql = "insert into student(name,age,sex) values('" + name+ "',21,'male')";
// update
sql = "update student set age=22 where id=12";
// delete
sql = "delete from student where name='tom'";
// 返回值为整数，表示影响数据库的行数
int n = stmt.executeUpdate(sql);
System.out.println(n);
if (n > 0) {
System.out.println("执行成功！");
}
案例三：// 1. 加载驱动
Class.forName("org.sqlite.JDBC");
// 2.创建数据库的连接
Connection conn = DriverManager
.getConnection("jdbc:sqlite:/c:/db1522.db");

String sql = "insert into student(name,age,sex) values(?,?,?)";

// 创建执行sql的PreparedStatement
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, "tom");
pstmt.setInt(2, 22);
pstmt.setString(3, "male");

int n = pstmt.executeUpdate();
if (n > 0)
System.out.println("success");

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