Oracle PL/SQL/Select Query/Query Select Columns
Содержание
Indicate the column names in query command
<source lang="sql">
SQL> SQL> -- create demo table SQL> create table Employee(
2 ID VARCHAR2(4 BYTE) NOT NULL, 3 First_Name VARCHAR2(10 BYTE), 4 Last_Name VARCHAR2(10 BYTE), 5 Start_Date DATE, 6 End_Date DATE, 7 Salary Number(8,2), 8 City VARCHAR2(10 BYTE), 9 Description VARCHAR2(15 BYTE) 10 ) 11 /
Table created. SQL> SQL> -- prepare data SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values ("01","Jason", "Martin", to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto", "Programmer")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("02","Alison", "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 2334.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("03","James", "Smith", to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 2334.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("04","Celia", "Rice", to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2334.78, "Vancouver","Manager")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("05","Robert", "Black", to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 2334.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("06","Linda", "Green", to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 2334.78,"New York", "Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("07","David", "Larry", to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 2334.78,"New York", "Manager")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("08","James", "Cat", to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 2334.78,"Vancouver", "Tester")
3 /
1 row created. SQL> SQL> SQL> SQL> -- display data in the table SQL> select * from Employee
2 /
ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION
---------- ---------- --------- --------- ---------- ---------- ---------------
01 Jason Martin 25-JUL-96 25-JUL-06 1234.56 Toronto Programmer 02 Alison Mathews 21-MAR-76 21-FEB-86 2334.78 Vancouver Tester 03 James Smith 12-DEC-78 15-MAR-90 2334.78 Vancouver Tester 04 Celia Rice 24-OCT-82 21-APR-99 2334.78 Vancouver Manager 05 Robert Black 15-JAN-84 08-AUG-98 2334.78 Vancouver Tester 06 Linda Green 30-JUL-87 04-JAN-96 2334.78 New York Tester 07 David Larry 31-DEC-90 12-FEB-98 2334.78 New York Manager 08 James Cat 17-SEP-96 15-APR-02 2334.78 Vancouver Tester 8 rows selected. SQL> SQL> SQL> SQL> SQL> SQL> SQL> SQL> --Indicate the column names in query command SQL> SQL> SELECT ID,First_Name,Last_Name,Start_Date,End_Date,Salary,City,Description FROM Employee; ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION
---------- ---------- --------- --------- ---------- ---------- ---------------
01 Jason Martin 25-JUL-96 25-JUL-06 1234.56 Toronto Programmer 02 Alison Mathews 21-MAR-76 21-FEB-86 2334.78 Vancouver Tester 03 James Smith 12-DEC-78 15-MAR-90 2334.78 Vancouver Tester 04 Celia Rice 24-OCT-82 21-APR-99 2334.78 Vancouver Manager 05 Robert Black 15-JAN-84 08-AUG-98 2334.78 Vancouver Tester 06 Linda Green 30-JUL-87 04-JAN-96 2334.78 New York Tester 07 David Larry 31-DEC-90 12-FEB-98 2334.78 New York Manager 08 James Cat 17-SEP-96 15-APR-02 2334.78 Vancouver Tester 8 rows selected. SQL> SQL> SQL> SQL> -- clean the table SQL> drop table Employee; Table dropped. SQL>
</source>
Query returning all rows and all columns from the table
<source lang="sql">
SQL> -- create demo table SQL> create table Employee(
2 ID VARCHAR2(4 BYTE) NOT NULL, 3 First_Name VARCHAR2(10 BYTE), 4 Last_Name VARCHAR2(10 BYTE), 5 Start_Date DATE, 6 End_Date DATE, 7 Salary Number(8,2), 8 City VARCHAR2(10 BYTE), 9 Description VARCHAR2(15 BYTE) 10 ) 11 /
Table created. SQL> SQL> -- prepare data SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values ("01","Jason", "Martin", to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto", "Programmer")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("02","Alison", "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 2334.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("03","James", "Smith", to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 2334.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("04","Celia", "Rice", to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2334.78, "Vancouver","Manager")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("05","Robert", "Black", to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 2334.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("06","Linda", "Green", to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 2334.78,"New York", "Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("07","David", "Larry", to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 2334.78,"New York", "Manager")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("08","James", "Cat", to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 2334.78,"Vancouver", "Tester")
3 /
1 row created. SQL> SQL> SQL> SQL> -- display data in the table SQL> select * from Employee
2 /
ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION
---------- ---------- --------- --------- ---------- ---------- ---------------
01 Jason Martin 25-JUL-96 25-JUL-06 1234.56 Toronto Programmer 02 Alison Mathews 21-MAR-76 21-FEB-86 2334.78 Vancouver Tester 03 James Smith 12-DEC-78 15-MAR-90 2334.78 Vancouver Tester 04 Celia Rice 24-OCT-82 21-APR-99 2334.78 Vancouver Manager 05 Robert Black 15-JAN-84 08-AUG-98 2334.78 Vancouver Tester 06 Linda Green 30-JUL-87 04-JAN-96 2334.78 New York Tester 07 David Larry 31-DEC-90 12-FEB-98 2334.78 New York Manager 08 James Cat 17-SEP-96 15-APR-02 2334.78 Vancouver Tester 8 rows selected. SQL> SQL> SQL> -- clean the table SQL> drop table Employee; Table dropped. SQL>
</source>
Reference one column more than once
<source lang="sql">
SQL> create table product(
2 product_id integer primary key 3 ,price number(7,2) 4 ,description varchar2(75) 5 ,onhand number(5,0) 6 ,reorder number(5,0) 7 ,supplier_no integer 8 );
Table created. SQL> -- product Table Inserts: SQL> insert into product(product_id, price, description, onhand, reorder)values (1,2.50,"Happy Birthday",100,20); 1 row created. SQL> insert into product(product_id, price, description, onhand, reorder)values (2,23.00,"Happy Birthday",null,null); 1 row created. SQL> insert into product(product_id, price, description, onhand, reorder)values (3,null,"Happy New Year",null,null); 1 row created. SQL> insert into product(product_id, price, description, onhand, reorder)values (4,1.50,"Happy New Year",50,10); 1 row created. SQL> SQL> SQL> select description, price, price * .068 as tax,
2 price * 1.068 as "Total" 3 from product;
DESCRIPTION
PRICE TAX Total
---------- ----------
Happy Birthday
2.5 .17 2.67
Happy Birthday
23 1.564 24.564
Happy New Year
Happy New Year
1.5 .102 1.602
4 rows selected. SQL> SQL> drop table product; Table dropped.
</source>
Reference renamed column in order by
<source lang="sql">
SQL> SQL> create table emp
2 ( empno NUMBER(4) constraint E_PK primary key 3 , ename VARCHAR2(8) 4 , init VARCHAR2(5) 5 , job VARCHAR2(8) 6 , mgr NUMBER(4) 7 , bdate DATE 8 , sal NUMBER(6,2) 9 , comm NUMBER(6,2) 10 , deptno NUMBER(2) default 10 11 ) ;
Table created. SQL> insert into emp values(1,"Tom","N", "Coder", 13,date "1965-12-17", 800 , NULL, 20); 1 row created. SQL> insert into emp values(2,"Jack","JAM", "Tester",6,date "1961-02-20", 1600, 300, 30); 1 row created. SQL> insert into emp values(3,"Wil","TF" , "Tester",6,date "1962-02-22", 1250, 500, 30); 1 row created. SQL> insert into emp values(4,"Jane","JM", "Designer", 9,date "1967-04-02", 2975, NULL, 20); 1 row created. SQL> insert into emp values(5,"Mary","P", "Tester",6,date "1956-09-28", 1250, 1400, 30); 1 row created. SQL> insert into emp values(6,"Black","R", "Designer", 9,date "1963-11-01", 2850, NULL, 30); 1 row created. SQL> insert into emp values(7,"Chris","AB", "Designer", 9,date "1965-06-09", 2450, NULL, 10); 1 row created. SQL> insert into emp values(8,"Smart","SCJ", "Coder", 4,date "1959-11-26", 3000, NULL, 20); 1 row created. SQL> insert into emp values(9,"Peter","CC", "Designer",NULL,date "1952-11-17", 5000, NULL, 10); 1 row created. SQL> insert into emp values(10,"Take","JJ", "Tester",6,date "1968-09-28", 1500, 0, 30); 1 row created. SQL> insert into emp values(11,"Ana","AA", "Coder", 8,date "1966-12-30", 1100, NULL, 20); 1 row created. SQL> insert into emp values(12,"Jane","R", "Manager", 6,date "1969-12-03", 800 , NULL, 30); 1 row created. SQL> insert into emp values(13,"Fake","MG", "Coder", 4,date "1959-02-13", 3000, NULL, 20); 1 row created. SQL> insert into emp values(14,"Mike","TJA","Manager", 7,date "1962-01-23", 1300, NULL, 10); 1 row created. SQL> SQL> select ename, 12*sal+comm yearsal
2 from emp 3 where job = "Tester" 4 order by yearsal desc;
ENAME YEARSAL
----------
Jack 19500 Take 18000 Mary 16400 Wil 15500 SQL> SQL> SQL> drop table emp; Table dropped.
</source>
Renaming a column with a longer name
<source lang="sql">
SQL> SQL> create table emp
2 ( empno NUMBER(4) constraint E_PK 3 primary key 4 , ename VARCHAR2(8) 5 , init VARCHAR2(5) 6 , job VARCHAR2(8) 7 , mgr NUMBER(4) 8 , bdate DATE 9 , sal NUMBER(6,2) 10 , comm NUMBER(6,2) 11 , deptno NUMBER(2) default 10 12 ) ;
Table created. SQL> insert into emp values(1,"Tom","N", "Coder", 13,date "1965-12-17", 800 , NULL, 20); 1 row created. SQL> insert into emp values(2,"Jack","JAM", "Tester",6,date "1961-02-20", 1600, 300, 30); 1 row created. SQL> insert into emp values(3,"Wil","TF" , "Tester",6,date "1962-02-22", 1250, 500, 30); 1 row created. SQL> insert into emp values(4,"Jane","JM", "Designer", 9,date "1967-04-02", 2975, NULL, 20); 1 row created. SQL> insert into emp values(5,"Mary","P", "Tester",6,date "1956-09-28", 1250, 1400, 30); 1 row created. SQL> insert into emp values(6,"Black","R", "Designer", 9,date "1963-11-01", 2850, NULL, 30); 1 row created. SQL> insert into emp values(7,"Chris","AB", "Designer", 9,date "1965-06-09", 2450, NULL, 10); 1 row created. SQL> insert into emp values(8,"Smart","SCJ", "Coder", 4,date "1959-11-26", 3000, NULL, 20); 1 row created. SQL> insert into emp values(9,"Peter","CC", "Designer",NULL,date "1952-11-17", 5000, NULL, 10); 1 row created. SQL> insert into emp values(10,"Take","JJ", "Tester",6,date "1968-09-28", 1500, 0, 30); 1 row created. SQL> insert into emp values(11,"Ana","AA", "Coder", 8,date "1966-12-30", 1100, NULL, 20); 1 row created. SQL> insert into emp values(12,"Jane","R", "Manager", 6,date "1969-12-03", 800 , NULL, 30); 1 row created. SQL> insert into emp values(13,"Fake","MG", "Coder", 4,date "1959-02-13", 3000, NULL, 20); 1 row created. SQL> insert into emp values(14,"Mike","TJA","Manager", 7,date "1962-01-23", 1300, NULL, 10); 1 row created. SQL> SQL> SQL> select ename, init, sal salary
2 from emp 3 where deptno = 30;
ENAME INIT SALARY
----- ----------
Jack JAM 1600 Wil TF 1250 Mary P 1250 Black R 2850 Take JJ 1500 Jane R 800 6 rows selected. SQL> SQL> drop table emp; Table dropped.
</source>
Return course name for an employee id
<source lang="sql">
SQL> CREATE TABLE emp
2 (id VARCHAR2(10) NOT NULL, 3 course VARCHAR2(10), 4 year VARCHAR2(4), 5 PRIMARY KEY (id));
Table created. SQL> SQL> SQL> CREATE OR REPLACE FUNCTION emp_Course(s_id emp.id%TYPE)
2 RETURN VARCHAR2 IS 3 v_course VARCHAR(10); 4 BEGIN 5 SELECT course INTO v_course 6 FROM emp 7 WHERE id = s_id; 8 RETURN v_course; 9 END emp_Course; 10 /
Function created. SQL> SQL> drop table emp; Table dropped.
</source>
Returning a Single Column.sql
<source lang="sql">
SQL> SQL> CREATE TABLE emp (
2 empID INT NOT NULL PRIMARY KEY, 3 Name VARCHAR(50) NOT NULL);
Table created. SQL> INSERT INTO emp (empID,Name) VALUES (1,"Victor"); 1 row created. SQL> INSERT INTO emp (empID,Name) VALUES (2,"Bill"); 1 row created. SQL> INSERT INTO emp (empID,Name) VALUES (3,"Mary"); 1 row created. SQL> INSERT INTO emp (empID,Name) VALUES (4,"Jack"); 1 row created. SQL> INSERT INTO emp (empID,Name) VALUES (5,"Peter"); 1 row created. SQL> INSERT INTO emp (empID,Name) VALUES (6,"Tom"); 1 row created. SQL> SQL> SQL> SELECT Name FROM emp; NAME
Victor Bill Mary Jack Peter Tom 6 rows selected. SQL> SQL> drop table emp; Table dropped.
</source>
