一、基础操作篇
1. 数据定义语言(DDL)核心操作
1.1 表结构设计技巧
-- 电商用户表设计示例
CREATE TABLE tb_users (
user_id NUMBER(10) PRIMARY KEY,
username VARCHAR2(30) UNIQUE NOT NULL,
password CHAR(32) DEFAULT 'e10adc3949ba59abbe56e057f20f883e',
email VARCHAR2(50) CHECK(email LIKE '%@%'),
reg_date DATE DEFAULT SYSDATE,
last_login TIMESTAMP
);
Java全栈实践:
在Spring Boot中通过JPA实现自动建表:
@Entity
public class User {
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE)
private Long userId;
@Column(unique = true, nullable = false)
private String username;
@Column(columnDefinition = "CHAR(32) DEFAULT 'e10adc3949ba59abbe56e057f20f883e'")
private String password;
@Column(name = "REG_DATE", insertable = false)
private LocalDateTime regDate;
}
2. 数据操作语言(DML)实战
-- 电商订单批量插入
INSERT ALL
INTO orders VALUES (1001, 301, SYSDATE, '待支付')
INTO orders VALUES (1002, 302, SYSDATE, '已发货')
SELECT * FROM DUAL;
-- 商品价格批量调整
UPDATE products
SET price = price * 0.9
WHERE category = '电子产品';
性能优化技巧:
使用JDBC批处理提升数据操作效率:
try (Connection conn = dataSource.getConnection();
PreparedStatement pstmt = conn.prepareStatement(
"INSERT INTO products VALUES (?, ?, ?)")) {
for(P