diff --git a/README.md b/README.md
index 111c3fd..84afab8 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,36 @@
 # learn_oracle_notebook
 
-Oracle 学习笔记
\ No newline at end of file
+Oracle 学习笔记
+
+## 查询 Select
+>
+> 查询语句
+
+当涉及到数据库查询时，子查询和表关联是非常常见的操作。让我通过一些简单的例子，并对每个例子进行简要的讲解来帮助你完善笔记。
+
+### 子查询
+
+#### 关联子查询
+
+```sql
+SELECT * 
+FROM employees 
+WHERE department_id IN 
+    (SELECT department_id 
+     FROM departments 
+     WHERE location_id = 1700);
+```
+
+这个例子演示了一个关联子查询。内部的子查询先根据条件从departments表中选择特定的部门ID，然后外部的主查询根据这些部门ID从employees表中检索相关的员工信息。这种方式可以帮助我们根据内部查询的结果来过滤外部查询的数据。
+
+### 表关联
+
+#### 左连接
+
+```sql
+SELECT customers.name, orders.order_date
+FROM customers
+LEFT JOIN orders ON customers.id = orders.customer_id;
+```
+
+这个例子演示了左连接，它返回了所有的顾客信息以及与之关联的订单信息。即使某些顾客没有订单，也会返回顾客的信息。这在需要显示所有主体数据的情况下非常有用。
diff --git a/course/01-practice.sql b/course/01-practice.sql
new file mode 100644
index 0000000..add9e6c
--- /dev/null
+++ b/course/01-practice.sql
@@ -0,0 +1,107 @@
+-- 查询名字中有 k
+-- 并薪水大于 2000 的员工姓名、薪水、以及年收入(12*(薪水+奖金))
+SELECT
+    ENAME,
+    SAL,
+    COMM,
+    NVL(COMM, 0),
+    12*(SAL+NVL(COMM, 0)) YEAR_SAL
+FROM
+    EMP
+WHERE
+    ENAME LIKE '%K%'
+    AND SAL > 2000;
+
+-- 查询那些部门的平均薪水大于2000
+SELECT
+    *
+FROM
+    (
+        SELECT
+            DEPTNO,
+            AVG(NVL(SAL, 0)) AVG_SAL
+        FROM
+            EMP
+        WHERE
+            DEPTNO IS NOT NULL
+        GROUP BY
+            DEPTNO
+        HAVING
+            AVG(NVL(SAL, 0)) > 2000
+        ORDER BY
+            DEPTNO
+    )    A
+    JOIN DEPT D
+    ON A.DEPTNO=D.DEPTNO;
+
+-- 那些人的薪水超过 10 部门的最高薪水
+SELECT
+    ENAME  姓名,
+    SAL    薪水,
+    DEPTNO 部门
+FROM
+    EMP E
+WHERE
+    E.SAL > (
+        SELECT
+            MAX(SAL)
+        FROM
+            EMP
+        WHERE
+            EMP.DEPTNO=20
+    );
+
+-- 查询各个部门的最低薪水
+SELECT
+    DEPTNO  部门号,
+    LOW_SAL 最低薪水
+FROM
+    (
+        SELECT
+            MIN(NVL(SAL, 0)) LOW_SAL
+        FROM
+            EMP
+        GROUP BY
+            DEPTNO
+    )   L
+    JOIN EMP E
+    ON L.LOW_SAL=E.SAL;
+
+SELECT
+    DEPTNO   部门号,
+    MIN(SAL) 最低薪水
+FROM
+    EMP
+GROUP BY
+    DEPTNO);
+
+-- 查询各个部门的平均大于20部门的平均薪水
+SELECT
+    DEPTNO,
+    AVG(NVL(SAL, 0))
+FROM
+    EMP
+WHERE
+    DEPTNO IS NOT NULL
+GROUP BY
+    DEPTNO
+HAVING
+    AVG(NVL(SAL, 0)) > (
+        SELECT
+            AVG(NVL(SAL, 0))
+        FROM
+            EMP
+        WHERE
+            DEPTNO=20
+    )
+ -- 查询员工姓名、薪水、部门号、和部门名称
+    SELECT
+        E.ENAME  姓名,
+        E.SAL    薪水,
+        E.ENAME  部门号,
+        E.DEPTNO 部门名称
+    FROM
+        EMP  E,
+        DEPT D
+    WHERE
+        E.DEPTNO=D.DEPTNO;
\ No newline at end of file
diff --git a/course/02-practice.sql b/course/02-practice.sql
new file mode 100644
index 0000000..b852f71
--- /dev/null
+++ b/course/02-practice.sql
@@ -0,0 +1,298 @@
+/*
+    练习2
+*/
+
+-- 创建数据表
+CREATE TABLE USER_SK (
+    ID NUMBER(4),
+    PASSWORD CHAR(4),
+    NAME CHAR(20),
+    PHONE CHAR(20),
+    EMAIL VARCHAR(50)
+);
+
+-- 为表添加数据
+INSERT INTO USER_SK VALUES(
+    1001,
+    '1234',
+    'liucs',
+    '13600000000',
+    'LIUCS@SINA.COM'
+);
+
+-- 查询数据
+SELECT
+    *
+FROM
+    USER_SK;
+
+/* 
+    案例-1
+*/
+-- 删除表
+DROP TABLE DEPT_SK;
+
+CREATE TABLE DEPT_SK(
+    DEPTNO NUMBER(2),
+    DNAME CHAR(20),
+    LOCATION CHAR(20)
+);
+
+INSERT INTO DEPT_SK VALUES(
+    10,
+    'developer',
+    'beijing'
+);
+
+INSERT INTO DEPT_SK VALUES(
+    20,
+    'account',
+    'shanghai'
+);
+
+INSERT INTO DEPT_SK VALUES(
+    30,
+    'sales',
+    'guangzhou'
+);
+
+INSERT INTO DEPT_SK VALUES(
+    40,
+    'operations',
+    'tianjin'
+);
+
+COMMIT;
+
+-- 查询创建的 DEPT_SK 表
+SELECT
+    *
+FROM
+    DEPT_SK;
+
+/* 
+    案例-1
+        创建表: EMP
+ */
+-- 创建表 EMP_SK
+CREATE TABLE EMP_SK(
+    EMPNO NUMBER(4),
+    ENAME VARCHAR2(20),
+    JOB VARCHAR2(15),
+    SALARY NUMBER(7, 2),
+    BONUS NUMBER(7, 2),
+    HIREDATE DATE,
+    MGR NUMBER(4),
+    DEPTNO NUMBER(10)
+);
+
+-- 插入数据
+INSERT INTO EMP_SK VALUES(
+    1001,
+    '张无忌',
+    'Manager',
+    10000,
+    2000,
+    '',
+    1005,
+    10
+);
+
+INSERT INTO EMP_SK VALUES(
+    1002,
+    '刘芒松',
+    'Analyst',
+    8000,
+    1000,
+    '',
+    NULL,
+    10
+);
+
+INSERT INTO EMP_SK VALUES(
+    1003,
+    '李翔',
+    'Analyst',
+    9000,
+    1000,
+    '',
+    1001,
+    10
+);
+
+INSERT INTO EMP_SK VALUES(
+    1004,
+    '郭英莹',
+    'Programmer',
+    5000,
+    NULL,
+    '',
+    1001,
+    10
+);
+
+INSERT INTO EMP_SK VALUES(
+    1005,
+    '张三丰',
+    'President',
+    15000,
+    NULL,
+    '',
+    NULL,
+    20
+);
+
+INSERT INTO EMP_SK VALUES(
+    1006,
+    '燕小六',
+    'Manager',
+    5000,
+    400,
+    '',
+    1005,
+    20
+);
+
+INSERT INTO EMP_SK VALUES(
+    1007,
+    '陆无双',
+    'Clerk',
+    3000,
+    500,
+    '',
+    1006,
+    20
+);
+
+INSERT INTO EMP_SK VALUES(
+    1008,
+    '黄莺',
+    'Manager',
+    5000,
+    500,
+    '',
+    1005,
+    30
+);
+
+INSERT INTO EMP_SK VALUES(
+    1009,
+    '乔小宝',
+    'Salesman',
+    4000,
+    NULL,
+    '',
+    1008,
+    30
+);
+
+INSERT INTO EMP_SK VALUES(
+    1010,
+    '郭琦',
+    'Salesman',
+    4500,
+    500,
+    '',
+    1008,
+    30
+);
+
+-- 设置显示格式
+set linesize 150;
+
+col empno for 9999;
+
+col mgr for 9999;
+
+col deptno for 99;
+
+col salary for 99999.99;
+
+-- 查询表
+SELECT
+    *
+FROM
+    EMP_SK;
+
+-- 插入一条ID 为1011, 姓名为 '余泽成', 其余字段为NULL 的数据
+INSERT INTO EMP_SK(
+    EMPNO,
+    ENAME
+) VALUES(
+    1011,
+    '余泽成'
+);
+
+-- 查询EMP_XXX 表, 如果没有职位, 显示'no position', 如果有职位, 显示员工的职位
+SELECT
+    ENAME,
+    NVL(JOB, '无职位')
+FROM
+    EMP_SK;
+
+/* 
+    案例2-关联子查询
+ */
+
+-- 哪些员工的薪水比公司的平均薪水低？
+SELECT
+    ENAME,
+    SALARY
+FROM
+    EMP_SK
+WHERE
+    SALARY < (
+        SELECT
+            AVG(NVL(SALARY, 0))
+        FROM
+            EMP_SK
+    );
+
+-- 哪些员工的薪水比本部门的平均薪水低？不再和整个部门的平均薪水比较。
+SELECT
+    E.ENAME,
+    E.SALARY,
+    E.DEPTNO
+FROM
+    EMP_SK E
+    JOIN (
+        SELECT
+            AVG(NVL(SALARY, 0)) NEW_SALARY,
+            DEPTNO
+        FROM
+            EMP_SK
+        WHERE
+            SALARY IS NOT NULL
+        GROUP BY
+            DEPTNO
+    ) NE
+    ON E.DEPTNO=NE.DEPTNO
+WHERE
+    E.SALARY < NE.NEW_SALARY
+ORDER BY
+    DEPTNO;
+
+-- 只查询当前时间
+SELECT
+    SYSDATE
+FROM
+    DUAL;
+
+/* 
+    案例3-关联子查询
+ */
+-- 哪些人是其他人的经理？( 查找有下属的员工 )
+SELECT
+    ENAME,
+    EMPNO
+FROM
+    EMP_SK E
+WHERE
+    EXISTS (
+        SELECT
+            1
+        FROM
+            EMP_SK
+        WHERE
+            MGR=E.EMPNO
+    );
\ No newline at end of file
diff --git a/course/03-practice.sql b/course/03-practice.sql
new file mode 100644
index 0000000..7d8a90a
--- /dev/null
+++ b/course/03-practice.sql
@@ -0,0 +1,135 @@
+/* 
+    Author: Fromsko
+    DATE:   2024.09.10 20:30
+*/
+
+-- 查询两个表
+SELECT
+    *
+FROM
+    EMP_WHC;
+
+SELECT
+    *
+FROM
+    DEPT_WHC;
+
+-- 工资大于张无忌的
+SELECT
+    ENAME,
+    SALARY
+FROM
+    EMP_WHC
+WHERE
+    SALARY > ANY(
+        SELECT
+            SALARY
+        FROM
+            EMP_WHC
+        WHERE
+            ENAME='张无忌'
+    );
+
+SELECT
+    ENAME,
+    DEPTNO
+FROM
+    EMP_WHC
+WHERE
+    DEPTNO IN (
+        SELECT
+            DEPTNO
+        FROM
+            EMP_WHC
+        WHERE
+            ENAME='张无忌'
+    )
+    AND ENAME<>'张无忌';
+
+SELECT
+    ENAME,
+    E.DEPTNO,
+    A.COU,
+    A.AVG_SAL
+FROM
+    EMP_WHC E,
+    (
+        SELECT
+            DEPTNO,
+            COUNT(*)            COU,
+            AVG(NVL(SALARY, 0)) AVG_SAL
+        FROM
+            EMP_WHC
+        WHERE
+            DEPTNO IS NOT NULL
+        GROUP BY
+            DEPTNO
+    )       A
+WHERE
+    E.DEPTNO = A.DEPTNO;
+
+--
+SELECT
+    DEPTNO,
+    AVG(NVL(SALARY, 0))
+FROM
+    EMP_WHC
+WHERE
+    DEPTNO IS NOT NULL
+GROUP BY
+    DEPTNO
+HAVING
+    AVG(NVL(SALARY, 0)) > (
+        SELECT
+            AVG(NVL(SALARY, 0))
+        FROM
+            EMP_WHC
+        WHERE
+            DEPTNO=20
+    );
+
+--列出员工的名字薪水和部门还有职位 要求这些员工所在
+--部门的人数比10部门的人数多
+SELECT
+    ENAME,
+    SALARY,
+    DEPTNO,
+    JOB
+FROM
+    EMP_WHC
+WHERE
+    DEPTNO IN (
+        SELECT
+            DEPTNO
+        FROM
+            EMP_WHC
+        WHERE
+            DEPTNO IS NOT NULL
+        GROUP BY
+            DEPTNO
+        HAVING
+            COUNT(*) > (
+                SELECT
+                    COUNT(*)
+                FROM
+                    EMP_WHC
+                WHERE
+                    DEPTNO =10
+            )
+    );
+
+--那些员工的薪水比本部门的平均薪水低?
+SELECT
+    ENAME,
+    SALARY
+FROM
+    EMP_WHC E
+WHERE
+    SALARY <(
+        SELECT
+            AVG(SALARY)
+        FROM
+            EMP_WHC
+        WHERE
+            DEPTNO = E.DEPTNO
+    )
\ No newline at end of file
diff --git a/course/03-test.sql b/course/03-test.sql
new file mode 100644
index 0000000..1a800db
--- /dev/null
+++ b/course/03-test.sql
@@ -0,0 +1,92 @@
+/* 
+    Author: Fromsko
+    DATE:   2024.09.10 20:30
+*/
+
+-- 更新赵敏的数据
+UPDATE EMP_WHC
+SET
+    MGR = 1002
+WHERE
+    ENAME = '赵敏';
+
+-- 总数居
+SELECT
+    *
+FROM
+    EMP_WHC;
+
+-- 谁是张无忌的下属？ (MGR=EMPNO=1002)
+SELECT
+    ENAME
+FROM
+    EMP_WHC
+WHERE
+    MGR IN (
+        SELECT
+            EMPNO
+        FROM
+            EMP_WHC
+        WHERE
+            ENAME='张无忌'
+    );
+
+--
+
+/* 
+    子查询:
+        子查询的条件是单列还是多列没关系,
+        关键是要分清返回的是单行还是多行
+
+        - 如果是单行, 用单行比较运算符, =, >, < 这些
+        - 如果是多行, 用IN, >ALL, >ANY, <ALL, <ANY 这些
+*/
+
+-- 每个部门拿最高薪水的是谁?
+
+--- 表外连接查法
+SELECT
+    E.ENAME,
+    E.SALARY,
+    E.DEPTNO
+FROM
+    EMP_WHC E
+    JOIN (
+        SELECT
+            DEPTNO,
+            MAX(SALARY) NEW_SALARY
+        FROM
+            EMP_WHC
+        WHERE
+            DEPTNO IS NOT NULL
+        GROUP BY
+            DEPTNO
+    ) R
+    ON E.DEPTNO=R.DEPTNO
+WHERE
+    E.SALARY=R.NEW_SALARY
+ORDER BY
+    E.DEPTNO;
+
+--- 子查询法
+SELECT
+    ENAME,
+    SALARY,
+    JOB,
+    DEPTNO
+FROM
+    EMP_WHC
+WHERE -- 顺序必须对上
+    (DEPTNO, SALARY) IN (
+        SELECT
+            DEPTNO,
+            MAX(SALARY) NEW_SALARY
+        FROM
+            EMP_WHC
+        WHERE
+            DEPTNO IS NOT NULL
+        GROUP BY
+            DEPTNO
+    )
+ORDER BY
+    DEPTNO;
\ No newline at end of file
diff --git a/course/db/01-base-db.sql b/course/db/01-base-db.sql
new file mode 100644
index 0000000..4ec84f1
--- /dev/null
+++ b/course/db/01-base-db.sql
@@ -0,0 +1,174 @@
+/*
+ Navicat Premium Data Transfer
+
+ Source Server         : 本地-Oracle
+ Source Server Type    : Oracle
+ Source Server Version : 110200 (Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
+With the Partitioning, OLAP, Data Mining and Real Application Testing options)
+ Source Host           : localhost:1521
+ Source Schema         : SCOTT
+
+ Target Server Type    : Oracle
+ Target Server Version : 110200 (Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
+With the Partitioning, OLAP, Data Mining and Real Application Testing options)
+ File Encoding         : 65001
+
+ Date: 10/09/2024 10:29:02
+*/
+
+
+-- ----------------------------
+-- Table structure for BONUS
+-- ----------------------------
+DROP TABLE "SCOTT"."BONUS";
+CREATE TABLE "SCOTT"."BONUS" (
+  "ENAME" VARCHAR2(10 BYTE),
+  "JOB" VARCHAR2(9 BYTE),
+  "SAL" NUMBER,
+  "COMM" NUMBER
+)
+LOGGING
+NOCOMPRESS
+PCTFREE 10
+INITRANS 1
+STORAGE (
+  BUFFER_POOL DEFAULT
+)
+PARALLEL 1
+NOCACHE
+DISABLE ROW MOVEMENT
+;
+
+-- ----------------------------
+-- Records of BONUS
+-- ----------------------------
+
+-- ----------------------------
+-- Table structure for DEPT
+-- ----------------------------
+DROP TABLE "SCOTT"."DEPT";
+CREATE TABLE "SCOTT"."DEPT" (
+  "DEPTNO" NUMBER(2,0) NOT NULL,
+  "DNAME" VARCHAR2(14 BYTE),
+  "LOC" VARCHAR2(13 BYTE)
+)
+LOGGING
+NOCOMPRESS
+PCTFREE 10
+INITRANS 1
+STORAGE (
+  INITIAL 65536 
+  NEXT 1048576 
+  MINEXTENTS 1
+  MAXEXTENTS 2147483645
+  BUFFER_POOL DEFAULT
+)
+PARALLEL 1
+NOCACHE
+DISABLE ROW MOVEMENT
+;
+
+-- ----------------------------
+-- Records of DEPT
+-- ----------------------------
+INSERT INTO "SCOTT"."DEPT" VALUES ('10', 'ACCOUNTING', 'NEW YORK');
+INSERT INTO "SCOTT"."DEPT" VALUES ('20', 'RESEARCH', 'DALLAS');
+INSERT INTO "SCOTT"."DEPT" VALUES ('30', 'SALES', 'CHICAGO');
+INSERT INTO "SCOTT"."DEPT" VALUES ('40', 'OPERATIONS', 'BOSTON');
+
+-- ----------------------------
+-- Table structure for EMP
+-- ----------------------------
+DROP TABLE "SCOTT"."EMP";
+CREATE TABLE "SCOTT"."EMP" (
+  "EMPNO" NUMBER(4,0) NOT NULL,
+  "ENAME" VARCHAR2(10 BYTE),
+  "JOB" VARCHAR2(9 BYTE),
+  "MGR" NUMBER(4,0),
+  "HIREDATE" DATE,
+  "SAL" NUMBER(7,2),
+  "COMM" NUMBER(7,2),
+  "DEPTNO" NUMBER(2,0)
+)
+LOGGING
+NOCOMPRESS
+PCTFREE 10
+INITRANS 1
+STORAGE (
+  INITIAL 65536 
+  NEXT 1048576 
+  MINEXTENTS 1
+  MAXEXTENTS 2147483645
+  BUFFER_POOL DEFAULT
+)
+PARALLEL 1
+NOCACHE
+DISABLE ROW MOVEMENT
+;
+
+-- ----------------------------
+-- Records of EMP
+-- ----------------------------
+INSERT INTO "SCOTT"."EMP" VALUES ('7369', 'SMITH', 'CLERK', '7902', TO_DATE('1980-12-17 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '800', NULL, '20');
+INSERT INTO "SCOTT"."EMP" VALUES ('7499', 'ALLEN', 'SALESMAN', '7698', TO_DATE('1981-02-20 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '1600', '300', '30');
+INSERT INTO "SCOTT"."EMP" VALUES ('7521', 'WARD', 'SALESMAN', '7698', TO_DATE('1981-02-22 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '1250', '500', '30');
+INSERT INTO "SCOTT"."EMP" VALUES ('7566', 'JONES', 'MANAGER', '7839', TO_DATE('1981-04-02 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '2975', NULL, '20');
+INSERT INTO "SCOTT"."EMP" VALUES ('7654', 'MARTIN', 'SALESMAN', '7698', TO_DATE('1981-09-28 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '1250', '1400', '30');
+INSERT INTO "SCOTT"."EMP" VALUES ('7698', 'BLAKE', 'MANAGER', '7839', TO_DATE('1981-05-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '2850', NULL, '30');
+INSERT INTO "SCOTT"."EMP" VALUES ('7782', 'CLARK', 'MANAGER', '7839', TO_DATE('1981-06-09 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '2450', NULL, '10');
+INSERT INTO "SCOTT"."EMP" VALUES ('7788', 'SCOTT', 'ANALYST', '7566', TO_DATE('1987-04-19 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '3000', NULL, '20');
+INSERT INTO "SCOTT"."EMP" VALUES ('7839', 'KING', 'PRESIDENT', NULL, TO_DATE('1981-11-17 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '5000', NULL, '10');
+INSERT INTO "SCOTT"."EMP" VALUES ('7844', 'TURNER', 'SALESMAN', '7698', TO_DATE('1981-09-08 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '1500', '0', '30');
+INSERT INTO "SCOTT"."EMP" VALUES ('7876', 'ADAMS', 'CLERK', '7788', TO_DATE('1987-05-23 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '1100', NULL, '20');
+INSERT INTO "SCOTT"."EMP" VALUES ('7900', 'JAMES', 'CLERK', '7698', TO_DATE('1981-12-03 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '950', NULL, '30');
+INSERT INTO "SCOTT"."EMP" VALUES ('7902', 'FORD', 'ANALYST', '7566', TO_DATE('1981-12-03 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '3000', NULL, '20');
+INSERT INTO "SCOTT"."EMP" VALUES ('7934', 'MILLER', 'CLERK', '7782', TO_DATE('1982-01-23 00:00:00', 'SYYYY-MM-DD HH24:MI:SS'), '1300', NULL, '10');
+
+-- ----------------------------
+-- Table structure for SALGRADE
+-- ----------------------------
+DROP TABLE "SCOTT"."SALGRADE";
+CREATE TABLE "SCOTT"."SALGRADE" (
+  "GRADE" NUMBER,
+  "LOSAL" NUMBER,
+  "HISAL" NUMBER
+)
+LOGGING
+NOCOMPRESS
+PCTFREE 10
+INITRANS 1
+STORAGE (
+  INITIAL 65536 
+  NEXT 1048576 
+  MINEXTENTS 1
+  MAXEXTENTS 2147483645
+  BUFFER_POOL DEFAULT
+)
+PARALLEL 1
+NOCACHE
+DISABLE ROW MOVEMENT
+;
+
+-- ----------------------------
+-- Records of SALGRADE
+-- ----------------------------
+INSERT INTO "SCOTT"."SALGRADE" VALUES ('1', '700', '1200');
+INSERT INTO "SCOTT"."SALGRADE" VALUES ('2', '1201', '1400');
+INSERT INTO "SCOTT"."SALGRADE" VALUES ('3', '1401', '2000');
+INSERT INTO "SCOTT"."SALGRADE" VALUES ('4', '2001', '3000');
+INSERT INTO "SCOTT"."SALGRADE" VALUES ('5', '3001', '9999');
+
+-- ----------------------------
+-- Primary Key structure for table DEPT
+-- ----------------------------
+ALTER TABLE "SCOTT"."DEPT" ADD CONSTRAINT "PK_DEPT" PRIMARY KEY ("DEPTNO");
+
+-- ----------------------------
+-- Primary Key structure for table EMP
+-- ----------------------------
+ALTER TABLE "SCOTT"."EMP" ADD CONSTRAINT "PK_EMP" PRIMARY KEY ("EMPNO");
+
+-- ----------------------------
+-- Foreign Keys structure for table EMP
+-- ----------------------------
+ALTER TABLE "SCOTT"."EMP" ADD CONSTRAINT "FK_DEPTNO" FOREIGN KEY ("DEPTNO") REFERENCES "SCOTT"."DEPT" ("DEPTNO") NOT DEFERRABLE INITIALLY IMMEDIATE NORELY VALIDATE;
diff --git a/course/db/02-two-tables.sql b/course/db/02-two-tables.sql
new file mode 100644
index 0000000..f49ebfb
--- /dev/null
+++ b/course/db/02-two-tables.sql
@@ -0,0 +1,297 @@
+CREATE TABLE EMP_WHC (
+    EMPNO NUMBER PRIMARY KEY,
+    ENAME VARCHAR2(50),
+    JOB VARCHAR2(50),
+    SALARY NUMBER(10, 2),
+    BONUS NUMBER(10, 2),
+    HIREDATE DATE,
+    MGR NUMBER,
+    DEPTNO NUMBER
+);
+
+INSERT INTO EMP_WHC (
+    EMPNO,
+    ENAME,
+    JOB,
+    SALARY,
+    BONUS,
+    HIREDATE,
+    MGR,
+    DEPTNO
+) VALUES (
+    1001,
+    '张三丰',
+    'BOSS',
+    88888.00,
+    8888.00,
+    TO_DATE('2010-01-01', 'YYYY-MM-DD'),
+    NULL,
+    10
+);
+
+INSERT INTO EMP_WHC (
+    EMPNO,
+    ENAME,
+    JOB,
+    SALARY,
+    BONUS,
+    HIREDATE,
+    MGR,
+    DEPTNO
+) VALUES (
+    1002,
+    '张无忌',
+    'Manager',
+    77777.00,
+    7777.00,
+    TO_DATE('2012-02-02', 'YYYY-MM-DD'),
+    1001,
+    10
+);
+
+INSERT INTO EMP_WHC (
+    EMPNO,
+    ENAME,
+    JOB,
+    SALARY,
+    BONUS,
+    HIREDATE,
+    MGR,
+    DEPTNO
+) VALUES (
+    1003,
+    '赵敏',
+    '财务',
+    20000.00,
+    500.00,
+    TO_DATE('2012-03-03', 'YYYY-MM-DD'),
+    1001,
+    20
+);
+
+INSERT INTO EMP_WHC (
+    EMPNO,
+    ENAME,
+    JOB,
+    SALARY,
+    BONUS,
+    HIREDATE,
+    MGR,
+    DEPTNO
+) VALUES (
+    1004,
+    '刘备',
+    'Manager',
+    66666.00,
+    6666.00,
+    TO_DATE('2014-04-04', 'YYYY-MM-DD'),
+    1001,
+    20
+);
+
+INSERT INTO EMP_WHC (
+    EMPNO,
+    ENAME,
+    JOB,
+    SALARY,
+    BONUS,
+    HIREDATE,
+    MGR,
+    DEPTNO
+) VALUES (
+    1005,
+    '关羽',
+    '市场',
+    3800.00,
+    2000.00,
+    TO_DATE('2014-05-05', 'YYYY-MM-DD'),
+    1004,
+    20
+);
+
+INSERT INTO EMP_WHC (
+    EMPNO,
+    ENAME,
+    JOB,
+    SALARY,
+    BONUS,
+    HIREDATE,
+    MGR,
+    DEPTNO
+) VALUES (
+    1006,
+    '张飞',
+    '市场',
+    3000.00,
+    1500.00,
+    TO_DATE('2014-06-06', 'YYYY-MM-DD'),
+    1004,
+    20
+);
+
+INSERT INTO EMP_WHC (
+    EMPNO,
+    ENAME,
+    JOB,
+    SALARY,
+    BONUS,
+    HIREDATE,
+    MGR,
+    DEPTNO
+) VALUES (
+    1007,
+    '唐三藏',
+    'Manager',
+    55555.00,
+    5555.00,
+    TO_DATE('2018-07-07', 'YYYY-MM-DD'),
+    1001,
+    30
+);
+
+INSERT INTO EMP_WHC (
+    EMPNO,
+    ENAME,
+    JOB,
+    SALARY,
+    BONUS,
+    HIREDATE,
+    MGR,
+    DEPTNO
+) VALUES (
+    1008,
+    '孙悟空',
+    '销售',
+    5000.00,
+    6000.00,
+    TO_DATE('2018-08-08', 'YYYY-MM-DD'),
+    1007,
+    30
+);
+
+INSERT INTO EMP_WHC (
+    EMPNO,
+    ENAME,
+    JOB,
+    SALARY,
+    BONUS,
+    HIREDATE,
+    MGR,
+    DEPTNO
+) VALUES (
+    1009,
+    '猪八戒',
+    '销售',
+    5000.00,
+    6000.00,
+    TO_DATE('2018-09-09', 'YYYY-MM-DD'),
+    1007,
+    30
+);
+
+INSERT INTO EMP_WHC (
+    EMPNO,
+    ENAME,
+    JOB,
+    SALARY,
+    BONUS,
+    HIREDATE,
+    MGR,
+    DEPTNO
+) VALUES (
+    1010,
+    '沙悟净',
+    '销售',
+    3000.00,
+    1000.00,
+    TO_DATE('2018-10-10', 'YYYY-MM-DD'),
+    1007,
+    30
+);
+
+INSERT INTO EMP_WHC (
+    EMPNO,
+    ENAME,
+    JOB,
+    SALARY,
+    BONUS,
+    HIREDATE,
+    MGR,
+    DEPTNO
+) VALUES (
+    1011,
+    '杨过',
+    'Manager',
+    4444.00,
+    NULL,
+    TO_DATE('2021-11-11', 'YYYY-MM-DD'),
+    1001,
+    40
+);
+
+SELECT
+    *
+FROM
+    EMP_WHC;
+
+-- 第二张表
+CREATE TABLE DEPT_WHC (
+    DEPTNO NUMBER PRIMARY KEY,
+    DNAME VARCHAR2(50),
+    LOCATION VARCHAR2(50)
+);
+
+INSERT INTO DEPT_WHC (
+    DEPTNO,
+    DNAME,
+    LOCATION
+) VALUES (
+    60,
+    '研发部',
+    '北京'
+);
+
+INSERT INTO DEPT_WHC (
+    DEPTNO,
+    DNAME,
+    LOCATION
+) VALUES (
+    10,
+    '财务部',
+    '张家界'
+);
+
+INSERT INTO DEPT_WHC (
+    DEPTNO,
+    DNAME,
+    LOCATION
+) VALUES (
+    20,
+    '市场部',
+    '南京'
+);
+
+INSERT INTO DEPT_WHC (
+    DEPTNO,
+    DNAME,
+    LOCATION
+) VALUES (
+    30,
+    '销售部',
+    '杭州'
+);
+
+INSERT INTO DEPT_WHC (
+    DEPTNO,
+    DNAME,
+    LOCATION
+) VALUES (
+    40,
+    '安保部',
+    '苏州'
+);
+
+SELECT
+    *
+FROM
+    DEPT_WHC;
\ No newline at end of file
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diff --git a/imgs/用户组特权登录.png b/imgs/用户组特权登录.png
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diff --git a/imgs/登录账户.png b/imgs/登录账户.png
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diff --git a/imgs/缓冲区执行-两种方式.png b/imgs/缓冲区执行-两种方式.png
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diff --git a/imgs/解锁账户.png b/imgs/解锁账户.png
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diff --git a/note/java_oracle_day01.pdf b/note/java_oracle_day01.pdf
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diff --git a/note/java_oracle_day02.pdf b/note/java_oracle_day02.pdf
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diff --git a/note/java_oracle_day04.pdf b/note/java_oracle_day04.pdf
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diff --git a/source/scott-tables-oracle.sql b/source/scott-tables-oracle.sql
new file mode 100644
index 0000000..703eeb4
--- /dev/null
+++ b/source/scott-tables-oracle.sql
@@ -0,0 +1,11 @@
+-- 显示用户
+SHOW user;
+
+-- 查询数据
+SELECT
+    *
+FROM
+    EMP;
+
+-- 显示结构
+DESC EMP;
diff --git a/source/sys-tables-oracle.sql b/source/sys-tables-oracle.sql
new file mode 100644
index 0000000..b65bdd3
--- /dev/null
+++ b/source/sys-tables-oracle.sql
@@ -0,0 +1,18 @@
+CREATE TABLESPACE WATERBOSS
+DATAFILE 'R:\waterboss.dbf'
+ 
+-- 分配大小
+SIZE 100m
+ 
+-- 自动扩展数据量
+AUTOEXTEND ON
+NEXT 10m
+ 
+-- 设置时间
+SET TIME ON;
+
+-- 输出用户
+SHOW USER;
+
+-- 修改显示行数
+SET LINESIZE 200;
\ No newline at end of file