CRUD Operations in postgreSQL
在PostgreSQL中执行CRUD操作通常涉及使用SQL语句。以下是一些基本的CRUD操作示例:
- 创建(Create):
CREATE TABLE users (
id SERIAL PRIMARY KEY,
username VARCHAR(50) UNIQUE NOT NULL,
password VARCHAR(50) NOT NULL,
email VARCHAR(100) NOT NULL
);
读取(Read):
- 获取所有数据:
SELECT * FROM users;
- 根据条件查询:
SELECT * FROM users WHERE id = 1;
- 更新(Update):
UPDATE users SET password = 'new_password' WHERE id = 1;
- 删除(Delete):
DELETE FROM users WHERE id = 1;
- 查询特定列:
SELECT username, email FROM users;
- 插入数据:
INSERT INTO users (username, password, email) VALUES ('user1', 'password1', 'user1@example.com');
确保在执行这些操作之前,你已经连接到了PostgreSQL数据库,并且你有适当的权限来创建表、插入数据、更新和删除记录。
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