wolfenstein 1981

目标：掌握SQL语句的基本语法;可以使用SQL语句完成简单查询功能;1.【范例】：查询emp表中的数据;select * from emp;EMPNO ename JOB MGR hiredate SAL COMM DEPTNO----- ---------- --------- ----- ----------- --------- --------- ------7369 SMITH Clerk 7902 1980/12/17 800.00 207499 ALLEN salesman 7698 1981/2/20 1600.00 300.00 307521 WARD salesman 7698 1981/2/22 1250.00 500.00 307566 JONES MANAGER 7839 1981/4/2 29

','BOSTON'); INSERT intoEmpVALUES(7369,'SMITH','Clerk',7902, To_date ('17-12-1980','dd-mm-yyyy'), -,NULL, -); INSERT intoEmpVALUES(7499,'ALLEN','salesman',7698, To_date ('20-2-1981','dd-mm-yyyy'), the, -, -); INSERT intoEmpVALUES(7521,'WARD','salesman',7698, To_date ('22-2-1981','dd-mm-yyyy'),1250, -, -); INSERT intoEmpVALUES(7566,'JONES','MANAGER',7839, To_date ('2-4-

(+, ' OPERATIONS ', ' BOSTON '), insert into EMP values (7369, ' S MITH ', ' Clerk ', 7902,to_date (' 17-12-1980 ', ' dd-mm-yyyy '), 800,null,20); INSERT into EMP VALUES (7499, ' ALLEN ', ' salesman ' , 7698, To_date (' 20-2-1981 ', ' dd-mm-yyyy '), 1600,300,30); INSERT into EMP VALUES (7521, ' WARD ', ' salesman ', 7698,to_date (' 22-2-1981 ', ' dd-mm-yyyy '), 1250,500,30); INSERT into EMP VALUES (7566, '

Stu VALUES (' s_1011 ', ' xxx ', null, NULL);============================================================================Department TableCREATE TABLE Dept (Deptno INT,dname VARCHAR (+),Loc VARCHAR (in));INSERT into Dept VALUES (' ACCOUNTING ', ' NEW YORK ');INSERT into Dept VALUES ("DALLAS");INSERT into Dept VALUES (' SALES ', ' CHICAGO ');INSERT into Dept VALUES (+, ' OPERATIONS ', ' BOSTON ');=============================================================================Employee TableCREATE TAB

In the development of the report, it is unavoidable to encounter the problem of row to column.For example, in the case of Scott's EMP in Oracle, you can use "Row to column" to count the number of people in each position in each department:The original data for Scott's EMP are: EMPNO Ename JOB MGR HireDate SAL COMM DEPTNO 7369 SMITH Clerk 7902 12/17/1980 800.00 　 20 7499

In the development of the report, it is unavoidable to encounter the problem of row to column.For example, in the case of Scott's EMP in Oracle, you can use "Row to column" to count the number of people in each position in each department:The original data for Scott's EMP are: EMPNO Ename JOB MGR HireDate SAL COMM DEPTNO 7369 SMITH Clerk 7902 12/17/1980 800.00 　 20 7499

(7,2), deptno number (2) CONSTRAINT FK _deptno REFERENCES DEPT); CREATE TABLE Bonus ( ename VARCHAR2 (Ten), job VARCHAR2 (9) , sal number, comm number); CREATE TABLE Salgrade ( grade number, losal number, hisal number);8. Insert test Data--deptINSERT into Dept VALUES (' ACCOUNTING ', ' NEW YORK '); INSERT into Dept VALUES ("DALLAS"); INSERT into Dept VALUES (' SALES ', ' CHICAGO '); INSERT into Dept VALUES (+, ' OPERATIONS ', ' BOSTON '); 9. Insert test Data--emp INSERT into EMP VALUES (7369

1. Installing FILE_FDWNeed to install FILE_FDW, usually into the PostgreSQL source package in the CONTRIB/FILE_FDW directory, execute:makemake installThen go into the database and execute the following SQL to install the FILE_FDW:CREATE EXTENSION file_fdw;CREATE SERVER file_fdw_server FOREIGN DATA WRAPPER file_fdw;2. Create an external tableTake the common EMP table as an example;Create foreign table EMP(empno integer NOT NULL,ename VARCHAR (Ten),Job VARCHAR (9),Mgr Integer,hiredate DATE,Sal NUM

', ' BOSTON '); --Employee Table CREATE TABLE EMP (empno int (4) NOT NULL, ename varchar (ten), Job varchar (9), Mgr Int (4), HireDate DATE, Sal DECIMAL (7,2), Comm DECIMAL (7,2), Deptno Int (2), DESC2 varchar (+) default 2); --Create/recreate primary, unique and FOREIGN KEY constraints ALTER TABLE EMP ADD constraint pk_emp primary key (EMPNO); ALTER TABLE EMP add constraint Fk_deptno foreign key (DEPTNO) references DEPT (DEPTNO); INSERT INTO EMP (EMPNO, ename, JOB, MGR, HireDate, SAL, COMM, D

', ' Sunqi ', +, ' male ');INSERT into Stu VALUES (' s_1008 ', ' Zhouba ', ' female ');INSERT into Stu VALUES (' s_1009 ', ' wujiu ', ' Male ');INSERT into Stu VALUES (' s_1010 ', ' Zhengshi ', 5, ' female ');INSERT into Stu VALUES (' s_1011 ', ' xxx ', null, NULL);//---------------------------------------------------------------CREATE table EMP (--Employee tableEmpnoint,--Employee NumberEnamevarchar (50),--Employee nameJobvarchar (,--) workMgrint,--Employee's boss's numberHiredatedate,--Date o

Tags: Create value ima display test sid ted. com xxxSimilar to Oracle's RowNumber () over (partition by xxx order by xxx ) statement, which is: sorting tables after grouping Creating a Test EMP table DROP TABLE IF EXISTS emp; CREATE TABLE emp (empno decimal (4,0) NOT NULL, ename varchar (TEN) default NULL, Job varchar (9) default NULL, Mgr D Ecimal (4,0) default NULL, HireDate datetime default NULL, sal decimal (7,2) default NULL, Comm Decimal (7,2) Default N ULL, Deptno decimal (2,0) default

-NOV-81 5000 10 7844 TURNER SA LESMAN 7698 08-SEP-81 1500 0 30 7876 adams clerk 7788 23-MAY-87 1100 20 7900 james clerk 7698 03-DEC-81 950 30 7902 ford analyst 7566 03-DEC-81 3000 20 7934 miller clerk 7782 23-JAN-82 1300 1016 rows selected. --- rollback successful! 2, Based on timestamp (you can find the DML operation time point and SCN through logminer) 05:43:31 SQL> delete from scott.emp1;14 rows deleted.05:44:25 SQL> flashback table scott.emp1 to timestamp to_timestamp('2011-03-18 04:50:00',

(7,2 ),COMMDOUBLE (7,2 ),DEPTNOBIGINT (2)); -- Records of EMP INSERTEMPVALUES (7369, 'Smith ', 'cler', 7902, '2017-12-17', 1980, NULL, 20 );INSERTEMPVALUES (7499, 'Allen ', 'Salesman', 7698, '2017-02-20', 1981, 30 );INSERTEMPVALUES (7521, 'ward ', 'salesman', 7698, '2017-02-22 ', 1981, 30 );INSERTEMPVALUES (7566, 'Jones ', 'manager', 7839, '2017-04-02', 1981,