表空间：主要就是用于存放表的物理空间
创建表空间：create tablespace ts1 datafile 'E:\ts1.dbf' size 50M;
自动扩展大小：create tablespace ts2 datafile 'E:\ts2.dbf' size 50M autoextend on next 10M;
设置最大空间：create tablespace ts3 datafile 'E:\ts3.dbf' size 50M autoextend on next 10M maxsize 1024M;
查看用户的表空间，在视图 Dba_Users 中查看
SELECT a.* from Dba_Users a
更改用户默认表空间：alter database default tablespace ts1;
表空间改名：alter tablespace ts1 rename to tss1;
删除表空间：drop tablespace ts3 including contents and datafiles;
序列：作为数据库里的对象，主要作用就是生成主键的唯一值
SELECT a.*,rowid FROM aa a
1:NEXTVAL、CURRVAL 序列两个重要属性
CREATE SEQUENCE A1_SEQ;
SELECT A1_SEQ.nextval FROM dual
SELECT A1_SEQ.currval FROM dual
2: START WITH 100
CREATE SEQUENCE A2_SEQ START WITH 100
SELECT A2_SEQ.nextval FROM dual
3: MINVALUE 5 MAXVALUE 100
CREATE SEQUENCE A3_SEQ MINVALUE 5 MAXVALUE 100
SELECT A3_SEQ.nextval FROM dual
4:INCREMENT BY
CREATE SEQUENCE A4_SEQ INCREMENT BY 3
SELECT A4_SEQ.nextval FROM dual
5:综合
CREATE SEQUENCE A5_SEQ START WITH 10 INCREMENT BY 1
SELECT A5_SEQ.nextval FROM dual
数据类型和函数
1：字符串
SELECT a.*,rowid FROM scott.emp a
substr 从位置1开始，截取长度为3位
SELECT substr(ename,1,3) FROM scott.emp a WHERE a.empno=7369
trim 删除左右两边空格
SELECT TRIM(ename) FROM scott.emp a WHERE a.empno=7369
2：NUMBER 数字：NUMBER(6,3) -> 123.456，六位数字，小数占三位
round
SELECT round(sal) FROM scott.emp a WHERE a.empno=7369
SELECT round(sal,1) FROM scott.emp a WHERE a.empno=7369
CEIL
SELECT CEIL(12.8) 薪水 FROM scott.emp a WHERE a.empno=7369
SELECT CEIL(-12.8) 薪水 FROM scott.emp a WHERE a.empno=7369
floor
SELECT floor(12.8) 薪水 FROM scott.emp a WHERE a.empno=7369;
SELECT floor(-12.8) 薪水 FROM scott.emp a WHERE a.empno=7369;
to_char：格式化数值
SELECT to_char(123.45,'0000.000') 薪水 FROM dual;
SELECT to_char(123.45,'9999.999') 薪水 FROM dual;
SELECT to_char(1231232.45,'99,999,999.99') 薪水 FROM dual;
SELECT to_char(1231232.454,'FM99,999,999.99') 薪水 FROM dual;
SELECT to_char(1231232.456,'FM99,999,999.99') 薪水 FROM dual;
SELECT to_char(1231232.45,'$99,999,999.99') 薪水 FROM dual;
SELECT to_char(1231232.45,'99,999,999.99C') 薪水 FROM dual;
3：日期函数
SELECT Sysdate from dual
SELECT Systimestamp from dual
SELECT add_months(Sysdate,2) from dual
SELECT last_day(SYSDATE) from dual
SELECT to_date('2055-12-25 15:55:11','YYYY-MM-DD HH24:MI:SS') from dual
SELECT extract(YEAR FROM Sysdate) from dual
SELECT extract(MONTH FROM Sysdate) from dual
SELECT extract(DAY FROM Sysdate) from dual
to_char：日期格式化
SELECT to_char(Sysdate,'yyyy-MM-DD') from dual
SELECT to_char(Sysdate,'yyyy-MM-DD HH24:MI:SS') from dual
4：聚合函数
SELECT sum(a.sal) FROM scott.emp a
SELECT AVG(a.sal) FROM scott.emp a
SELECT MIN(a.sal) FROM scott.emp a
SELECT MAX(a.sal) FROM scott.emp a
SELECT COUNT(a.sal) FROM scott.emp a
NVL 如果为空，则为第二个数，不为空则为第一个结果
SELECT a.* FROM scott.emp a
SELECT a.ename,nvl(a.comm, 0) FROM scott.emp a
SELECT a.ename,nvl(a.comm+ 111, 10) FROM scott.emp a
LIKE 模糊查询
SELECT a.* FROM scott.emp a WHERE a.ename LIKE '%M%'
SELECT a.* FROM scott.emp a WHERE a.ename LIKE 'M%'
SELECT a.* FROM scott.emp a WHERE a.ename LIKE '_M%'
权限：
SELECT a.* from User_Role_Privs a;查看用户的角色
SELECT a.* from Dba_Sys_Privs a WHERE a.grantee='DBA';查看角色对应的权限
GRANT DBA TO scott;授权用户dba角色
视图：虚拟的表，所以dml也就是对实体表进行操作。我们一般创建只读视图
SELECT a.*,rowid from emp a;
创建视图
CREATE VIEW e_emp1 AS SELECT empno,ename,job FROM emp;
SELECT a.* from e_emp1 a
INSERT INTO e_emp1 (empno,ename,job) VALUES('8888','sb','销售');
SELECT a.* from emp a;
创建只读视图
CREATE VIEW e_emp2 AS SELECT empno,ename,job FROM emp with READ ONLY;
流程结构:
在SQL 命令窗口 执行 后面 +/ 再按enter
SET serverout ON;
DECLARE n NUMBER:=1;
v Varchar2(20):='world';
BEGIN
dbms_output.put_line('hello'||n||v);
END;
注意分号
SET serverout ON;
DECLARE emp_count NUMBER;
BEGIN
SELECT COUNT(*) INTO emp_count FROM emp WHERE sal>=3000;
IF emp_count >0 THEN
dbms_output.put_line('有'||emp_count||'个员工大于3000');
ELSE
dbms_output.put_line('没有员工大于3000');
END IF;
END;
- 有多少个if 就有多少个end if
SET serverout ON;
DECLARE emp_count NUMBER;
BEGIN
SELECT COUNT(*) INTO emp_count FROM emp WHERE sal>=3000;
IF emp_count =1 THEN
dbms_output.put_line('有'||emp_count||'个员工等于3000');
ELSE IF emp_count>1 THEN
dbms_output.put_line('有'||emp_count||'个员工大于3000');
ELSE
dbms_output.put_line('没有员工大于3000');
END IF;
END IF;
END;
- CASE WHEN
SET serverout ON;
DECLARE emp_count NUMBER;
BEGIN
SELECT COUNT(*) INTO emp_count FROM emp WHERE sal>=3000;
CASE emp_count
WHEN 0 THEN dbms_output.put_line('有'||emp_count||'个员工等于3000');
WHEN 1 THEN dbms_output.put_line('有'||emp_count||'个员工等于3000');
WHEN 2 THEN dbms_output.put_line('有'||emp_count||'个员工等于3000');
WHEN 3 THEN dbms_output.put_line('有'||emp_count||'个员工等于3000');
ELSE dbms_output.put_line('有'||emp_count||'个员工等于3000');
END CASE;
END;
SELECT a.* from salgrade a;
- LOOP 循环：
SET serverout ON;
DECLARE g_id NUMBER:=2;
g_losal NUMBER;
g_hisal NUMBER;
BEGIN
LOOP
IF (g_id>4) THEN
EXIT;
END IF;
SELECT losal,hisal INTO g_losal,g_hisal FROM salgrade WHERE grade=g_id;
dbms_output.put_line('编号'||g_id||'的最低工资'||g_losal||',和最高工资'||g_hisal);
g_id:=g_id+1;
END LOOP;
END;
- WHILE：
SET serverout ON;
DECLARE g_id NUMBER:=2;
g_losal NUMBER;
g_hisal NUMBER;
BEGIN
WHILE g_id<5 LOOP
SELECT losal,hisal INTO g_losal,g_hisal FROM salgrade WHERE grade=g_id;
dbms_output.put_line('编号'||g_id||'的最低工资'||g_losal||',和最高工资'||g_hisal);
g_id:=g_id+1;
END LOOP;
END;
- FOR 循环
SET serverout ON;
DECLARE g_losal NUMBER;
g_hisal NUMBER;
BEGIN
for g_id IN 2..4 LOOP
SELECT losal,hisal INTO g_losal,g_hisal FROM salgrade WHERE grade=g_id;
dbms_output.put_line('编号'||g_id||'的最低工资'||g_losal||',和最高工资'||g_hisal);
END LOOP;
END;
SELECT a.* FROM emp a;
游标
SET serverout ON;
DECLARE CURSOR cu_emp IS SELECT empno,ename,sal FROM emp;
c_no emp.empno%TYPE;
c_name emp.ename%TYPE;
c_sal emp.sal%TYPE;
BEGIN
OPEN cu_emp;
FETCH cu_emp INTO c_no,c_name,c_sal;
WHILE cu_emp%FOUND LOOP
dbms_output.put_line('编号'||c_no||','||c_name||','||c_sal);
FETCH cu_emp INTO c_no,c_name,c_sal;
END LOOP;
CLOSE cu_emp;
END;
- 弱类型游标
SET serverout ON;
DECLARE TYPE customType IS REF CURSOR;
e_count NUMBER;
e emp%ROWTYPE;
s salgrade%ROWTYPE;
cType customType;
BEGIN
SELECT COUNT(*) INTO e_count FROM emp WHERE job = 'clerk';
IF e_count > 0 THEN
OPEN cType FOR SELECT * FROM salgrade;
FETCH cType INTO s;
WHILE cType%FOUND LOOP
dbms_output.put_line(s.grade||s.losal);
FETCH cType INTO s;
END LOOP;
CLOSE cType;
ELSE
OPEN cType FOR SELECT * FROM emp;
FETCH cType INTO e;
WHILE cType%FOUND LOOP
dbms_output.put_line(e.empno||e.ename);
FETCH cType INTO e;
END LOOP;
CLOSE cType;
END IF;
END;
触发器：一般是用于权限控制
- 语句触发器
CREATE TRIGGER t_trigger
BEFORE INSERT
ON t_book
BEGIN
IF USER !='SCOTT' THEN
raise_application_error(-20001,'权限不足');
END IF;
END;
INSERT INTO t_book(ID,name,idtype) VALUES (4,'xx',1);
SELECT a.* from t_book a;
CREATE TRIGGER t_trigger2
BEFORE UPDATE OR DELETE
ON t_book
BEGIN
IF USER !='SCOTT1' THEN
raise_application_error(-20001,'权限不足');
END IF;
END;
UPDATE t_book SET NAME='ttyy',idtype=2 WHERE ID =4;
DELETE FROM t_book WHERE ID=4;
CREATE TRIGGER t_trigger3
AFTER UPDATE OR DELETE OR INSERT
ON t_book
BEGIN
IF updating THEN
INSERT INTO actionlog(actionUser,actionType,actionTime) VALUES(USER,'update',SYSDATE);
ELSE IF inserting THEN
INSERT INTO actionlog(actionUser,actionType,actionTime) VALUES(USER,'inert',SYSDATE);
ELSE IF deleting THEN
INSERT INTO actionlog(actionUser,actionType,actionTime) VALUES(USER,'delete',SYSDATE);
END IF;
END IF;
END IF;
END;
UPDATE t_book SET NAME='yy',idtype=2 WHERE ID =4;
DELETE FROM t_book WHERE ID=4;
SELECT a.* from actionlog a;
SELECT a.* from t_book a FOR UPDATE;
SELECT a.* from t_type a FOR UPDATE;
SELECT a.* from actionlog a FOR UPDATE;
- 行触发器：针对每一行 两个内置对象 :OLD :NEW
CREATE TRIGGER t_trigger4
AFTER INSERT
ON t_book
FOR EACH ROW
BEGIN
UPDATE t_type SET NUM = NUM+1 WHERE ID = :now.idtype;
END;
INSERT into t_book (ID,NAME,Idtype)VALUES(5,'xx',1);
CREATE TRIGGER t_trigger5
AFTER DELETE
ON t_book
FOR EACH ROW
BEGIN
UPDATE t_type SET NUM = NUM-1 WHERE ID = :old.idtype;
END;
DELETE from t_book WHERE ID = 5;
自定义函数：要有返回值
CREATE FUNCTION getCountBook RETURN NUMBER AS
BEGIN
DECLARE countNum NUMBER;
BEGIN
SELECT COUNT(*) INTO countNum FROM t_book;
RETURN countNum;
END;
END getCountBook;
调用：
SET serverout ON;
BEGIN
dbms_output.put_line('数量：'|| getCountBook());
END;
SELECT getCountBook() 数量 from dual;
- 带参数函数：
CREATE FUNCTION getTableCount(tableName VARCHAR2) RETURN NUMBER AS
BEGIN
DECLARE countNum NUMBER;
querySql VARCHAR2(200);
BEGIN
querySql:='select count(*) from '||tableName;
EXECUTE IMMEDIATE querySql INTO countNum;
RETURN countNum;
END;
END getTableCount;
SELECT getTableCount('emp') 数量 from dual;
存储过程：项目怎么用？
CREATE PROCEDURE proInsertBook(bname IN VARCHAR2,bidtype IN NUMBER) AS
BEGIN
DECLARE maxId NUMBER;
BEGIN
SELECT MAX(ID) INTO maxId FROM t_book;
INSERT into t_book(ID,NAME,idtype)VALUES(maxId+1,bname,bidtype);
COMMIT;
END;
END proInsertBook;
CREATE PROCEDURE proInsertBook2(bname IN VARCHAR2,bidtype IN NUMBER) AS
BEGIN
DECLARE maxId NUMBER;
bookNum NUMBER;
BEGIN
SELECT COUNT(*) INTO bookNum FROM t_book WHERE NAME=bname;
IF bookNum>0 THEN
RETURN;
END IF;
SELECT MAX(ID) INTO maxId FROM t_book;
INSERT into t_book(ID,NAME,idtype)VALUES(maxId+1,bname,bidtype);
COMMIT;
END;
END proInsertBook2;
CREATE PROCEDURE proInsertBook3(bname IN VARCHAR2,bidtype IN NUMBER,n1 OUT NUMBER,n2 OUT NUMBER) AS
BEGIN
DECLARE maxId NUMBER;
bookNum NUMBER;
BEGIN
SELECT COUNT(*) INTO n1 FROM t_book;
SELECT COUNT(*) INTO bookNum FROM t_book WHERE NAME=bname;
IF bookNum>0 THEN
RETURN;
END IF;
SELECT MAX(ID) INTO maxId FROM t_book;
INSERT into t_book(ID,NAME,idtype)VALUES(maxId+1,bname,bidtype);
SELECT COUNT(*) INTO n2 FROM t_book;
COMMIT;
END;
END proInsertBook3;
调用：
在SQL窗口：
CALL proInsertBook2('小心翼55',2);
begin
proInsertBook('小心翼翼3',2);
end;
在命令窗口：
exec proInsertBook('小心翼翼',2);
EXECUTE proInsertBook('小心翼翼',2);
CALL proInsertBook('小心翼翼',2);
SELECT a.* from t_book a;
DECLARE n1 NUMBER;
n2 NUMBER;
BEGIN
proInsertBook3('5454',2,n1,n2);
dbms_output.put_line('n1='||n1);
END;
CALL proInsertBook3('32321',2,n1,n2);
用户、权限、角色：
概念
关系
常用查询
导出表结构和表数据
-
表结构
方式一
方式二 -
表数据
方式一
方式二
方式三
导出方案
导出方案
导出数据库
导出数据库
导入
导入