Oracle19C入门到熟练024-JDBC

学习要求

有一定关系型数据的操作功底，会SQL语句

教学目标

熟练掌握Java如何操作Oracle数据库

概念

到这，Oracle基本的操作基本上都讲完了，下面说下编程语言如何操作Oracle数据库，本篇以Java为例子。

项目准备

1>建库，建表

使用sott 用户中的dept表/emp表作为例子

dept

编号	字段	类型	描述
1	DEPTNO	NUMBER(2)	部门编号
2	DNAME	VARCHAR2(14)	部门名称
3	LOC	VARCHAR2(13)	部门位置

emp 

编号	字段	类型	描述
1	EMPNO	NUMBER(4)	雇员编号
2	ENAME	VARCHAR2(10)	表示雇员姓名
3	JOB	VARCHAR2(9)	表示工作职位
4	MGR	NUMBER(4)	表示一个雇员的领导编号
5	HIREDATE	DATE	表示雇佣日期
6	SAL	NUMBER(7,2)	表示月薪，工资
7	COMM	NUMBER(7,2)	表示奖金或佣金
8	DEPTNO	NUMBER(2)	表示部门编号

创建maven项目oracle-demo-jdbc

这里自己去搭建，如果不会，建议先学习一下maven相关知识点 

导入oracle，jdbc操作依赖

这里需要注意，操作的oracle版本需要跟jdk版本对应，否则会导致兼容问题

导入依赖

<dependencies>
    <dependency>
        <groupId>com.oracle.database.jdbc</groupId>
        <artifactId>ojdbc10</artifactId>
        <version>19.10.0.0</version>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.16</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter</artifactId>
        <version>RELEASE</version>
        <scope>compile</scope>
    </dependency>
</dependencies>

 这里需要额外注意：因为oracle安全协议，maven并不会下载对应的jar进入仓库， 需要自己额外打包

mvn install:install-file -Dfile=本地jar包所在路径\ojdbc10-19.10.0.0.jar -DgroupId=com.oracle.database.jdbc -DartifactId=ojdbc10 -Dversion=19.10.0.0 -Dpackaging=jar

-Dfile：指定本地jar所在路径

-DgroupId：包路径

-DartifactId：包名

-Dversion：包版本

注意：jar需要到oracle官网或者maven仓库去下载， 下载完成之后， 包路径，包名， 版本名必须一直，否则mvn命令执行会失败。

编写jdbc连接操作代码

@Setter
@Getter
@ToString
public class Department {
    private Long deptno;
    private String dname;
    private String loc;
}

@Test
public static void testConn() throws Exception {

    String url ="jdbc:oracle:thin:@localhost:1521:ORCL";
    String uname="scott";
    String pwd="tiger";
    Class.forName("oracle.jdbc.OracleDriver");//加载具体的驱动类
    Connection connection = DriverManager.getConnection(url, uname, pwd);
    System.out.println(connection);
    connection.close();
}

增删改查

增

如果需要id自动增长，需要提前创建一个id序列

create sequence dept_id_seq increment by 1 start with 1;

@Test
public  void testAdd() throws Exception {
	String url="jdbc:oracle:thin:@localhost:1521:ORCL";
	String uname="scott";
	String pwd="tiger";
	Class.forName("oracle.jdbc.OracleDriver");//加载具体的驱动类
	Connection connection = DriverManager.getConnection(url, uname, pwd);

	String sql = "insert into dept(deptno, dname, loc) values(dept_id_seq.nextval,?,?)";

	PreparedStatement ps = connection.prepareStatement(sql);
	ps.setString(1, "小卖部");
	ps.setString(2, "广州");
	ps.execute();
	ps.close();
	connection.close();
}

删

@Test
public  void testDelete() throws Exception {
	String url="jdbc:oracle:thin:@localhost:1521:ORCL";
	String uname="scott";
	String pwd="tiger";
	Class.forName("oracle.jdbc.OracleDriver");//加载具体的驱动类
	Connection connection = DriverManager.getConnection(url, uname, pwd);

	String sql = "delete from dept where deptno = ?";

	PreparedStatement ps = connection.prepareStatement(sql);
	ps.setLong(1, 1L);
	ps.execute();
	ps.close();
	connection.close();
}

改

@Test
public  void testUpdate() throws Exception {
	String url="jdbc:oracle:thin:@localhost:1521:ORCL";
	String uname="scott";
	String pwd="tiger";
	Class.forName("oracle.jdbc.OracleDriver");//加载具体的驱动类
	Connection connection = DriverManager.getConnection(url, uname, pwd);

	String sql = "update dept set dname=? where deptno = ?";

	PreparedStatement ps = connection.prepareStatement(sql);
	ps.setString(1, "大卖部");
	ps.setLong(2, 1L);
	ps.execute();
	ps.close();
	connection.close();
}

查

@Test
public static void testQuery() throws Exception {
    String url="jdbc:oracle:thin:@localhost:1521:ORCL";
    String uname="scott";
    String pwd="tiger";
    Class.forName("oracle.jdbc.OracleDriver");//加载具体的驱动类
    Connection connection = DriverManager.getConnection(url, uname, pwd);
    PreparedStatement ps = connection.prepareStatement("select * from dept");
    ResultSet rs = ps.executeQuery();
    while(rs.next()){
        Department department = new Department();
        department.setDeptno(rs.getLong("deptno"));
        department.setDname(rs.getString("dname"));
        department.setLoc(rs.getString("loc"));
        System.out.println(department);
    }
    rs.close();
    ps.close();
    connection.close();
}

分页

//分页信息分组对象
@Getter
public class PageResult<T> {
    private int currentPage;        //当前页
    private int pageSize;           //每页显示条数
    private int totalCount;        //总记录数
    private List<T> data;           //当前页显示数据集
    private int prePage;            //上一页
    private int nextPage;           //下一页
    private int totalPage;          //总页数
    public PageResult(int currentPage, int pageSize, int totalCount, List<T> data){
        this.currentPage = currentPage;
        this.pageSize = pageSize;
        this.totalCount = totalCount;
        this.data = data;
        if(totalCount == 0){
            this.prePage = 1;
            this.totalPage = 1;
            this.nextPage = 1;
        }
        this.totalPage = totalCount % pageSize == 0? totalCount/pageSize : totalCount / pageSize + 1;
        this.prePage = currentPage > 1 ? currentPage - 1 : 1;
        this.nextPage = currentPage > totalPage ? currentPage + 1 : totalPage;
    }
}

@Test
public  void testPage() throws Exception {
	String url="jdbc:oracle:thin:@localhost:1521:ORCL";
	String uname="scott";
	String pwd="tiger";
	Class.forName("oracle.jdbc.OracleDriver");//加载具体的驱动类
	Connection connection = DriverManager.getConnection(url, uname, pwd);

	//查总数
	String totalsql = "select count(1) from dept ";
	PreparedStatement ps = connection.prepareStatement(totalsql);
	ResultSet countRS = ps.executeQuery();
	int totalCount = 0;
	while (countRS.next()){
		totalCount = countRS.getInt(1);
	}
	countRS.close();
	ps.close();

	//模拟页面传入：currentPage  pageSize
	int currentPage = 1;
	int pageSize = 3;

	int skip = (currentPage - 1) * pageSize;
	String sql = "select * from dept  offset ?  rows fetch next ? rows only";
	ps = connection.prepareStatement(sql);

	ps.setInt(1, skip);
	ps.setInt(2, pageSize);

	ResultSet rs = ps.executeQuery();

	List<Department> data = new ArrayList<>();

	while(rs.next()){
		Department department = new Department();
		department.setDeptno(rs.getLong("deptno"));
		department.setDname(rs.getString("dname"));
		department.setLoc(rs.getString("loc"));
		data.add(department);
	}
	//分页对象
	PageResult<Department> page = new PageResult<Department>(currentPage, pageSize, totalCount, data);
	System.out.println("当前页：" + page.getCurrentPage());
	System.out.println("上一页：" + page.getPrePage());
	System.out.println("下一页：" + page.getNextPage());
	System.out.println("总页数：" + page.getTotalPage());
	System.out.println("每页显示：" + page.getPageSize());
	System.out.println("每页数据：" );
	page.getData().forEach(System.out::println);

	rs.close();
	ps.execute();
	ps.close();
	connection.close();
}

存储过程/函数

jdbc 调用存储过程/函数有2种格式

{?= call <procedure-name>[(<arg1>,<arg2>, ...)]}  //包含结果参数的调用形式   如：函数（funciton）
{call <procedure-name>[(<arg1>,<arg2>, ...)]}  //不包含结果参数的调用形式     如：存储过程（procedure）

设置参数

in输入型

setXXX(int parameterIndex,XXX x) //主要用于设置过程调用时候需要的输入参数信息  其中XXX代表对应类型  

out输出型

void registerOutParameter(int parameterIndex, int sqlType)  
        throws SQLException; //在调用存储过程的时候设置输出参数的类型，用于接收输出结果  

其中sqlType 通过OracleTypes枚举类型指定

public abstract class OracleTypes {
    public static final int BIT = -7;
    public static final int TINYINT = -6;
    public static final int SMALLINT = 5;
    public static final int INTEGER = 4;
    public static final int BIGINT = -5;
    public static final int FLOAT = 6;
    public static final int REAL = 7;
    public static final int DOUBLE = 8;
    public static final int NUMERIC = 2;
    public static final int DECIMAL = 3;
    public static final int CHAR = 1;
    public static final int VARCHAR = 12;
    public static final int LONGVARCHAR = -1;
    public static final int DATE = 91;
    public static final int TIME = 92;
    public static final int TIMESTAMP = 93;
    public static final int PLSQL_BOOLEAN = 252;
    /** @deprecated */
    public static final int TIMESTAMPNS = -100;
    public static final int TIMESTAMPTZ = -101;
    public static final int TIMESTAMPLTZ = -102;
    public static final int INTERVALYM = -103;
    public static final int INTERVALDS = -104;
    public static final int BINARY = -2;
    public static final int VARBINARY = -3;
    public static final int LONGVARBINARY = -4;
    public static final int ROWID = -8;
    public static final int CURSOR = -10;
    public static final int BLOB = 2004;
    public static final int CLOB = 2005;
    public static final int BFILE = -13;
    public static final int STRUCT = 2002;
    public static final int ARRAY = 2003;
    public static final int REF = 2006;
    public static final int NCHAR = -15;
    public static final int NCLOB = 2011;
    public static final int NVARCHAR = -9;
    public static final int LONGNVARCHAR = -16;
    public static final int SQLXML = 2009;
    public static final int REF_CURSOR = 2012;
    public static final int OPAQUE = 2007;
    public static final int JAVA_STRUCT = 2008;
    public static final int JAVA_OBJECT = 2000;
    public static final int PLSQL_INDEX_TABLE = -14;
    public static final int BINARY_FLOAT = 100;
    public static final int BINARY_DOUBLE = 101;
    public static final int NULL = 0;
    public static final int NUMBER = 2;
    public static final int RAW = -2;
    public static final int OTHER = 1111;
    public static final int FIXED_CHAR = 999;
    public static final int DATALINK = 70;
    public static final int BOOLEAN = 16;

    public OracleTypes() {
    }
}

返回值

getXXX(int x) //主要用于获取过程调用后返回的参数的信息 

定义存储过程

-- 给指定员工加100工资
create or replace procedure addSal(v_eno in number) 
	is
	v_sal number;
begin
	update emp set sal = sal + 100 where empno = v_eno;
	dbms_output.put_line('操作成功');
end;

调用存储过程

@Test
public  void testPro() throws Exception {
	String url="jdbc:oracle:thin:@localhost:1521:ORCL";
	String uname="scott";
	String pwd="tiger";
	Class.forName("oracle.jdbc.OracleDriver");//加载具体的驱动类
	Connection connection = DriverManager.getConnection(url, uname, pwd);

	//调用存储过程， 指定名称
	CallableStatement cs = connection.prepareCall("{call addSal(?)}");
	//传入参数
	cs.setLong(1,7981);
	cs.execute();

	cs.close();
	connection.close();
}

定义函数

-- 调用函数
create or replace function findEmpYearSal(pno in number,pname out varchar2,psal out number)
  return number
as
  pcomm emp.comm%type;
begin
  select ename,sal,comm into pname,psal,pcomm from emp where empno=pno;
  return psal*12+nvl(pcomm,0);
end;

调用函数

@Test
public  void testFun() throws Exception {
	String url="jdbc:oracle:thin:@localhost:1521:ORCL";
	String uname="scott";
	String pwd="tiger";
	Class.forName("oracle.jdbc.OracleDriver");//加载具体的驱动类
	Connection connection = DriverManager.getConnection(url, uname, pwd);

	//调用存储过程， 指定名称
	CallableStatement cs = connection.prepareCall("{? = call findEmpYearSal(?,?,?)}");
	//设置返回值类型
	cs.registerOutParameter(1, OracleTypes.DOUBLE);
	cs.setLong(2,7981);

	cs.registerOutParameter(3, OracleTypes.VARCHAR);
	cs.registerOutParameter(4, OracleTypes.NUMBER);
	cs.execute();
	System.out.println("年薪：" + cs.getDouble(1));
	System.out.println("姓名：" + cs.getString(3));
	System.out.println("月薪：" + cs.getString(4));

	cs.close();
	connection.close();
}