1.格式:
sql0. 建表: CREATE TABLE 表名(属性 类型,属性 类型,...); 🔵 1. 增(INSERT) INSERT INTO 表名 VALUES (值1, 值2, 值3, ...); 🟢 2. 查(SELECT) SELECT 列1, 列2 FROM 表名 WHERE 条件; SELECT * FROM 表名 WHERE 条件行值; SELECT * FROM 表名; 查所有表 🟡 3. 改(UPDATE) UPDATE 表名 SET 列1 = 新值, 列2 = 新值 WHERE 条件; 🔴 4. 删(DELETE) DELETE FROM 表名 WHERE 条件; → 永久生效 COMMIT; → 恢复原状 ROLLBACK;
2.例子:
sql
**✅ 建表**
CREATE TABLE xiehe_doctor (doctor_id NUMBER, name VARCHAR2(50), dept VARCHAR2(100), title VARCHAR2(50));
**✅ 插数据**
INSERT INTO xiehe_doctor VALUES (101, '李医生', '心内科', '主任医师');
INSERT INTO xiehe_doctor VALUES (102, '宁医生', '五官科', '主治医师');
INSERT INTO xiehe_doctor VALUES (103, '张医生', '耳鼻喉科', '副主任医师');
COMMIT;
**✅ 查询**
SELECT * FROM xiehe_doctor;
SELECT name, title FROM xiehe_doctor;
SELECT * FROM xiehe_doctor WHERE dept = '心内科';
**✅ 修改**
UPDATE xiehe_doctor SET title = '主任医师' WHERE doctor_id = 103;
COMMIT;
3.具体对应:
sql
🔵 1. 增(INSERT)
INSERT INTO 表名 VALUES (值1, 值2, 值3, ...);
INSERT INTO xiehe_doctor VALUES (101, '李主任', '心内科', '主任医师');
COMMIT;
🟢 2. 查(SELECT)
SELECT 列1, 列2 FROM 表名 WHERE 条件;
SELECT name, dept FROM xiehe_doctor WHERE doctor_id = 101;
SELECT * FROM xiehe_doctor WHERE dept = '心内科';
🟡 3. 改(UPDATE)
UPDATE 表名 SET 列1 = 新值, 列2 = 新值 WHERE 条件;
UPDATE xiehe_doctor SET title = '主任医师' WHERE doctor_id = 103;
UPDATE xiehe_doctor SET dept = '神经内科' WHERE name = '张医生';
COMMIT;
🔴 4. 删(DELETE)
DELETE FROM 表名 WHERE 条件;
✅ 正确(有 WHERE):
-- 先确认
SELECT * FROM xiehe_doctor WHERE doctor_id = 103;
-- 再删除
DELETE FROM xiehe_doctor WHERE doctor_id = 103;
COMMIT;
-- 删除所有儿科医生
DELETE FROM xiehe_doctor WHERE dept = '儿科';
COMMIT;
❌ 危险(无 WHERE = 删全表):
DELETE FROM xiehe_doctor;