Easy SQL Practice

8/3/2019 Easy SQL Practice

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SQL – Structured Query Language

Data Definition Language (DDL)1. Create2. Alter

3. Drop4. Truncate5. Rename

To create a TableEx:

Create Table cig_emp(empno number,name varchar2(25),doj date,job varchar2(25),salnumber,deptno number);

To View the Structure of the Table.SQL>Describe cig_emp;

Or SQL>Desc cig_emp;

To Alter the Table Structure?SQL> Alter Table Cig_Emp modify(job varchar2(20));

Note: To resize the column width of Job

To add one more column in the existing table.SQL> Alter Table Cig_emp Add(Blood_Group varchar2(10));

To Delete the unwanted Column.

SQL> Alter Table Cig_emp Drop(Blood_Group);To Rename the Column NameSQL> ALter Table Dept1 Rename column Deptno To Dno;

To Delete the Table.SQL>Drop Table CIG_EMP;

To remove the data from the table.SQL> Truncate Table CIG_Emp;

To rename the Table NameSQL>Rename CIG_EMP To CIG_EMP1;

2. Data Manipulation LanguageINSERTUPDATEDELETE



MERGE

Ex:SQL>Insert into CIG_EMP Values(1000, ‘Raghu’, ’02-Apr-2008’, ‘Tech_Consult’,20000, 40);

For Continuous InputSQL> insert into cig_emp values(&empno,'&name','&doj','&job',&sal,&dno);

Note: Use /

For insert in desired field onlySQL > Insert into CIG_EMP(empno,name) Values (100,’Seenu’);

For insert all rows to a new tableSql> Insert into Dept1 ( Select * from dept )

5 rows created.Data Retrieval - SelectTo View the DataSQL> Select * From CIG_EMP;

To view Selected ColumnsSQL> Select Empno, Name from CIG_EMP;

How to view the Desired Record?To view the Record of ‘Raghu’SQL> select * from CIg_EMP Where empno=1001;or SQL> select * from CIg_EMP Where name='Raghu';

To view the records of name starts with ‘r’?SQL> select * from cig_emp where name like 'r%';

Note: % - For Multicharacters. _ For Single Character.SQL> select * from cig_emp where name like '_a%';

To view the records Last character as ‘r’?SQL> select * from cig_emp where name like '%r';

To view the records : empno >=1002SQL> select * from cig_emp where empno>=1002;

Using In to extract Data?SQL> select * from cig_emp where empno in (1000,1003);SQL> select * from cig_emp where name in ('Raghu','raja');



Using ANDSQL> Select * from emp where job='CLERK' AND SAL > 1000;SQL> SELECT * FROM EMP WHERE SAL >=1000 AND SAL <=2000;

Using OR SQL> select * from emp where job = 'CLERK' OR job = 'MANAGER';SQL> SELECT * FROM EMP WHERE JOB IN ('MANAGER','CLERK');

Between andSQL> select * from emp where sal between 1000 and 2000;

Not (except 1000 to 2000)SQL> select * from emp where sal not between 1000 and 2000;SQL> select * from emp where not job='MANAGER';

SQL> SELECT * FROM EMP WHERE JOB NOT IN ('MANAGER','CLERK');SQL> Select name from trial where name like '%\_%' ESCAPE '\';

NAME--------------------st_thomassri_ramajayamlathika_saranabi_nayaaa_rvinthan

Note: Search for special characters : By using ESCAPE

24.09.2008To Insert Data in particular fields.SQL> Insert into cig_emp (Empno,Name) values(2000,'Vignesh');

Update : To made Changes in Existing Records.Ex:

SQL> Update Cig_Emp1 Set DOJ='02-May-2008' where empno=2000; Note: Update in a Single Field.

SQL> Update Cig_Emp1 Set Job='DBA',sal=5000,deptno=30 where name='Vignesh'; Note: To update in multiple Fields.

SQL> Update CIG_EMP1 set sal=sal*1.20; Note: To increase 20% of sal to all employees.



CONSTRAINTS1. NOT NULL2. UNIQUE3. CHECK

4. PRIMARY KEY (UNIQUE + NOT NULL)5. FOREIGN KEY

To create the table with Primary Key & Not NullSQL> CREATE TABLE CIG_EMP2(ENO NUMBER PRIMARY KEY,NAMEVARCHAR2(30) NOT NULL,DEPTNO NUMBER,SAL NUMBER);

Note: We can’t enter duplicate values in ENO & with out leaving the NAME Field.

How to set Default Value .SQL> CREATE TABLE CIG_EMP2(ENO NUMBER PRIMARY KEY,NAMEVARCHAR2(30) NOT NULL,DOJ DATE DEFAULT SYSDATE,DEPTNO

NUMBER);Ex:SQL> INSERT INTO CIG_EMP2(ENO,NAME,DEPTNO) VALUES(&ENO,'&NAME',&DNO);Or SQL> INSERT INTO CIG_EMP2 (ENO,NAME,DEPTNO) VALUES(1000,'ASHOK',40);

SQL> Insert into CIG_EMP2 values (1004,'Raghu','02-May-2008',40); Note: If we give value then take that value otherwise take the default value.

CHECK SQL> Create table cig_emp3 (eno number primary key,name varchar2(30) notnull,deptno number check(deptno<50));

Note: Allows deptno is less than 50

How to Add Not Null in existing Column?SQL> Alter table cig modify(name varchar2(20) NOT NULL);

How To add constraint?SQL> Alter table cig add constraint cons1 PRIMARY KEY(no);

Add Primary Key for Column SetsSQL> CREATE TABLE TR _ TAB 1(ID NUMBER , NAME VARCHAR 2(20), SAL NUMBER , CONSTRAINT TR _ CONS PRIMARY KEY(ID, NAME ))

Note: If we create as like above then it check for 2 columns not a single column.



Ex: SQL> select * from tr_tab1;

ID NAME SAL---------- -------------------- ----------

1000 Saran 2500

1000 Seenu 25002000 Seenu 2500

How to Handle More than one Table?1. List EmpNo, Name, DepartmentNo, Department Name,JOBSQL> select cig_emp2.eno,cig_emp2.name,cig_emp2.deptno,cig_dept.dname fromcig_emp2,cig_dept where cig_emp2.deptno = cig_dept.deptno;

By using ALIAS Name to the TableSQL> Select e.eno,e.name,d.dname from cig_emp2 e,cig_dept d where

e.deptno=d.deptno;

SortingSQL> select * from cig_emp2 order by name;

Note: In Default : Ascending

DescendingSQL> select * from cig_emp2 order by name desc;

FunctionsSingle Row Function

• General functions:– NVL– NVL2– NULLIF– COALESCE– CASE

– DECODE

Function DescriptionNVL Converts a null value to an actual value

NVL2 If expr1 is not null, NVL2 returns expr2 . If expr1 is null, NVL2 returns expr3 .The argument expr1 can have any data type.

NULLIF Compares two expressions and returns null if they are equal, or the firstexpression if they are not equal

COALESCE Returns the first non-null expression in the expression list



Ex: NVLSQL> select empno,ename,nvl(comm,100) from emp;

Note: Substitute the value 100 for null value.

SQL> select ename,sal*nvl(comm,1) from emp;

SQL> select empno,ename,nvl(hiredate,sysdate) from emp; Note: Show system date for null of hiredate

SQL> select empno,nvl(ename,'Prasanth') from emp;

NVL2SQL> Select empno,ename,comm,nvl2(comm,'YES','NO') "Commision Status" fromemp;

Ex:EMPNO ENAME COMM Com

---------- ---------- ---------- ---7369 SMITH NO7499 ALLEN 300 YES7521 WARD 500 YES7566 JONES NO

NULLIFSyntaxNULLIF ( expr1 , expr2 )In the syntax:expr1 is the source value compared to expr2expr2 is the source value compared with expr1 . (If it is not equal to expr1 , expr1is returned.)

Note: The NULLIF function is logically equivalent to the following CASE expression. TheCASEexpression is discussed in a subsequent page:CASE WHEN expr1 = expr 2 THEN NULL ELSE expr1 END

Ex:SQL> select ename,job,NULLIF(EMPNO,MGR) "NULLIF" FROM EMP;

ENAME JOB NULLIF---------- --------- ----------SMITH CLERK 7369ALLEN SALESMAN 7499WARD SALESMAN 7521JONES MANAGER 7566XX Sales 1321the manager 1121Saran 100ASHOK TECH

The COALESCE FunctionThe COALESCE function returns the first non-null expression in the list.



SyntaxCOALESCE ( expr1 , expr2, ... exprn )In the syntax:expr1 returns this expression if it is not nullexpr2 returns this expression if the first expression is null and this expression is notnullexprn returns this expression if the preceding expressions are null

SQL> Select ename,coalesce(comm,sal,1000) "COALESCE" From emp;

ENAME COALESCE---------- ----------SMITH 800ALLEN 300WARD 500JONES 2975MARTIN 1400the 5000Saran 1000ASHOK 25

Conditional Expressions• Provide the use of IF-THEN-ELSE logic within aSQL statement• Use two methods:– CASE expression

– DECODE function

SQL> Select ename,job,sal "Current Salary", CASE JOBWhen 'CLERK' THEN 1.10 * SAL

2 When 'SALESMAN' Then 1.15 * sal3 When 'MANAGER' Then 1.20 * Sal4 ELSE5 Sal6 End "Revised Salary" From Emp;

ENAME JOB Current Salary Revised Salary

---------- --------- -------------- --------------SMITH CLERK 800 880ALLEN SALESMAN 1600 1840WARD SALESMAN 1250 1437.5JONES MANAGER 2975 3570MARTIN SALESMAN 1250 1437.5BLAKE MANAGER 2850 3420kannan SALESMAN 850 977.5



SCOTT ANALYST 300 300

SQL> Select Ename,Job,Sal "Current Salary", DECODE(Job, 'CLERK', 1.10 * Sal,'SALESMAN',1.15 * Sal, 'MANAGER', 1.20 * Sal, sal) "Revised Sal" From Emp;

ENAME JOB Current Salary Revised Sal---------- --------- -------------- -----------SMITH CLERK 800 880ALLEN SALESMAN 1600 1840WARD SALESMAN 1250 1437.5JONES MANAGER 2975 3570MARTIN SALESMAN 1250 1437.5BLAKE MANAGER 2850 3420

Try it Yourself

1. Find a Grade for the Employees Depends upon theSalary:

‘A’ > 3000‘B’ > 2000 & <=3000‘C’ Others

27-09-2008

Character-Manipulation FunctionsThese functions manipulate character strings:

CONCAT – To Add more than one text.Ex:1SQL> select concat('Hello',' World') from Dual;

CONCAT('HEL-----------Hello World

SQL> Select Concat(Ename,Job) from Emp;CONCAT(ENAME,JOB)-------------------SMITHCLERK

ALLENSALESMAN

WARDSALESMANJONESMANAGER

In Real Time Example.SQL> Select ename || ' is a ' || job "Ename with Job" From Emp;

Ename with Job



-------------------------SMITH is a CLERKALLEN is a SALESMANWARD is a SALESMANJONES is a MANAGER

SUBSTR – To extract a particular character(s) from theexisting text.Syntax: SubStr(text,startpos,no.of Char)SQL> Select SubStr('Murshidh',4,5) from dual;

SUBST-----Shidh

SQL> Select SubStr('Ashok',3) from Dual;

SUB---Hok

To extract from Right of the Text.SQL> Select Substr(ename,-3) from emp;

SUB---ITHLEN

LENGTH

SQL> Select Length('Ashok') from Dual;LENGTH('ASHOK')---------------

5

SQL> Select Ename, Length(Ename) "Length" from Emp;

ENAME Length---------- ----------SMITH 5ALLEN 5



SQL> Select * from Emp where Length(Ename)=5;

EMPNO ENAME JOB MGR HIREDATE---------- ---------- --------- ---------- ---------

7369 SMITH CLERK 7902 17-DEC-80

7499 ALLEN SALESMAN 7698 20-FEB-817566 JONES MANAGER 7839 02-APR-81

OrSQL> Select * from emp Where Ename Like '_____';

EMPNO ENAME JOB MGR HIREDATE---------- ---------- --------- ---------- ---------

7369 SMITH CLERK 7902 17-DEC-807499 ALLEN SALESMAN 7698 20-FEB-817566 JONES MANAGER 7839 02-APR-81

INSTR – To find the Position of the Character in the Text.

SQL> Select Instr('Ashok','o') From Dual;

INSTR('ASHOK','O')------------------

4

SQL> Select Instr('Murshidh','o') From Dual;

INSTR('MURSHIDH','O')---------------------

0

SQL> Select Instr('amirtha','a') From Dual;

INSTR('AMIRTHA','A')--------------------

1

SQL> Select Instr('amirtha','a',2) From Dual;

INSTR('AMIRTHA','A',2)----------------------

7

Exercise:Extract the Characters upto second ‘-‘ in a columnSQL> select * from ex1;



COL1------------------------------5676-2345-6572-567256-57-565

567-676-752-1105-7865-656-756

ResultSelect Substr(col1,1,Instr(col1,'-',instr(col1,'-')+1)-1)from ex1/SUBSTR(COL1,1,INSTR(COL1,'-',I------------------------------5676-234556-57567-6765-7865

LPAD – To Add Given Character in Left Side (For filling theEmpty Space)SQL> Select LPAD('Saranya',20,'#') From Dual;

LPAD('SARANYA',20,'#--------------------#############Saranya

SQL> Select Lpad(Ename,25,'*') From Emp;

LPAD(ENAME,25,'*')-------------------------********************SMITH********************ALLEN*********************WARD

RPAD – To Add Given Character in Right Side (For fillingthe Empty Space)

SQL> Select Rpad('Kiran',20,'$') From Dual;

RPAD('KIRAN',20,'$')--------------------Kiran$$$$$$$$$$$$$$$

SQL> Select Rpad(sal,15,'%') From emp;



RPAD(SAL,15,'%'---------------800%%%%%%%%%%%%1600%%%%%%%%%%%

1250%%%%%%%%%%%TRIM – To remove the blank space or first character of atext.SQL> Select Trim('a' From 'aaaalagi') from dual;TRIM----LagiSQL> select trim(ename) from emp;

TRIM(ENAME----------SMITHALLEN

29.09.2008Replace :Syntax: Replace(Text,Searching Text, Replacing Text);

Ex:SQL> Select Replace('saravanan','a','z') from dual;

REPLACE('---------szrzvznznSQL> Select Replace ('This is sample','is','was') from dual;

REPLACE('THISISS----------------Thwas was sample

SQL> select ename,replace(ename,'a','x') from emp;

ENAME REPLACE(EN---------- ----------kannan kxnnxnSCOTT SCOTTkannan kxnnxnthe thekumar kumxrnithya1 nithyx1



To remove all ‘a’ in a Given TextSQL>select replace('aaaalagi','a') from dual

REP

---lgi

Case Manipulation FunctionsThese functions convert case for character strings.LOWER(’SQL Course’)UPPER(’SQL Course’)INITCAP(’SQL Course’)

SQL> Select Lower('AShok') From dual;

LOWER-----ashokSQL> SelectLower(ename),Upper(Ename),Initcap(Ename) From emp;

LOWER(ENAM UPPER(ENAM INITCAP(EN---------- ---------- ----------smith SMITH Smith

allen ALLEN Allenward WARD Wardjones JONES Jonesmartin MARTIN Martin

Number Functions• ROUND: Rounds value to specified decimalROUND(45.926, 2) 45.93SQL> SELECT ROUND(45.923,2), ROUND(45.923,0),

2 ROUND(45.923,-1)3 FROM DUAL;

ROUND(45.923,2) ROUND(45.923,0) ROUND(45.923,-1)-------------- --------------- ----------------

45.92 46 50

• TRUNC: Truncates value to specified decimal



TRUNC(45.926, 2) 45.92

SQL> select round(2000.3589,2),Trunc(2000.3589,2)From Dual;

ROUND(2000.3589,2) TRUNC(2000.3589,2)------------------ ------------------

2000.36 2000.35

SQL> Select Round(3564.25,-2) from Dual;

ROUND(3564.25,-2)-----------------

3600

TRUNC(3554.25,-3)-----------------

3000

• MOD: Returns remainder of division MOD(1600, 300) 100

SQL> Select Mod(26,5) from dual;

MOD(26,5)

---------- 1Calculate the remainder of a salary after it is dividedby 5000 for all employees whose job title is salesrepresentative.

SELECT last_name, salary, MOD(salary, 5000)FROM employees WHERE job_id = 'SA_REP'/

LAST_NAME SALARY MOD(SALARY,5000)

-------------------- ---------- ----------------Abel 11000 1000Grant 7000 2000

Date FunctionsTo view the System DateSQL> select sysdate from dual;



SYSDATE---------29-SEP-08

Arithmetic with Dates• Add or subtract a number to or from a date for aresultant date value.• Subtract two dates to find the number of days

between those dates.• Add hours to a date by dividing the number ofhours by 24.

SQL> SELECT last_name, (SYSDATE-hire_date)/7 ASWEEKS FROM employees WHERE department_id = 90;

LAST_NAME WEEKS-------------------- ----------King 1110.78507Kochhar 992.642216De Haan 818.92793

For example, display the employee number, hire date, number of months employed, six-month review date, first Friday after hire date, and last day of the hire month for allemployees employed for fewer than 36 months.

SQL> SELECT employee_id, hire_date,2 MONTHS_BETWEEN (SYSDATE, hire_date) TENURE,3 ADD_MONTHS (hire_date, 6) REVIEW,4 NEXT_DAY (hire_date, 'FRIDAY'),

LAST_DAY(hire_date)5* FROM employees

EMPLOYEE_ID HIRE_DATE TENURE REVIEW NEXT_DAY( LAST_DAY(

---------- --------- ---------- --------- --------- ---------100 17-JUN-87 255.403214 17-DEC-87 19-JUN-87 30-JUN-87101 21-SEP-89 228.274182 21-MAR-90 22-SEP-89 30-SEP-89102 19-JAN-93 188.338698 19-JUL-93 22-JAN-93 31-JAN-93103 03-JAN-90 224.854827 03-JUL-90 05-JAN-90 31-JAN-90104 21-MAY-91 208.274182 21-NOV-91 24-MAY-91 31-MAY-91

Using Date Functions



• MONTHS_BETWEEN (’01-SEP-95’,’11-JAN-94’)SQL> Select Round(Months_Between(Sysdate,To_Date('15-Jan-1975'))/12) From Dual;

•

ADD_MONTHS (’11-JAN-94’,6)SQL> Select Sysdate,ADD_MONTHS(SYSDATE,6) FromDual;

SYSDATE ADD_MONTH--------- ---------29-SEP-08 29-MAR-09

• NEXT_DAY (’01-SEP-95’,’FRIDAY’)SQL> Select Sysdate,Next_Day(SYSDATE,'WEDNESDAY')

From Dual;

SYSDATE NEXT_DAY(--------- ---------29-SEP-08 01-OCT-08

• LAST_DAY(’01-FEB-95’)SQL> Select Last_Day(Sysdate) From Dual;

LAST_DAY(---------30-SEP-08

Explicit Data Type Conversion

To_CharSQL> Select sysdate,To_Char(sysdate,'MM/YY') FromDual;

SYSDATE TO_CH--------- -----29-SEP-08 09/08

AS Like We use the Below Terms YYYY YEARMM



MONTHDYDAYMONDD

To Spelled the YearSQL> Select To_Char(sysdate,'YEAR') From Dual;

TO_CHAR(SYSDATE,'YEAR')------------------------------------------TWO THOUSAND EIGHT

To Spelled the day

SQL> Select To_Char(To_Date('15-Jan-75'),'ddspth')from dual;

TO_CHAR(TO_DAT--------------Fifteenth

To Spelled the Day of the DateSQL> Select To_Char(sysdate,'DAY') From Dual;

TO_CHAR(S---------MONDAYNote: For ‘MON’ – Use ‘DY’

To Spelled the Month of the DateSQL> Select To_Char(sysdate,'MONTH') From Dual;

TO_CHAR(S---------

SEPTEMBERNote: For ‘JAN’ – Use ‘MON’

To Show in Roman LetterSQL> Select To_Char(sysdate,'RM') From Dual;

TO_C



----IX

SQL> Select To_Char(sysdate,'DD "of" Month') From Dual;

TO_CHAR(SYSDATE---------------29 of September

SQL> Select To_char(sysdate,'DD') || ' of ' ||To_Char(sysdate,'Month') from dual;

TO_CHAR(SYSDATE

---------------29 of September

SQL> SELECT last_name,2 TO_CHAR(hire_date, 'fmDD Month YYYY')3 AS HIREDATE4* FROM employees;

LAST_NAME HIREDATE-------------------- -----------------

King 17 June 1987Kochhar 21 September 1989De Haan 19 January 1993Hunold 3 January 1990Ernst 21 May 1991

9 Represents a number

0 Forces a zero to be displayed

$ Places a floating dollar sign

L Uses the floating local currency symbol

. Prints a decimal point



, Prints a thousand indicator

SQL> Select To_Char(sal,'9,99,999.99') from emp;

TO_CHAR(SAL,------------

800.001,600.001,250.002,975.001,250.002,850.00

SQL>Select To_Char(sal,'0,99,999.99') from empTO_CHAR(SAL,------------

0,00,800.000,01,600.000,01,250.00

SQL > Select To_Char(sal,'$9,99,999.99') from emp;

TO_CHAR(SAL,'-------------$800.00

$1,600.00$1,250.00$2,975.00

SQL > Select To_Char(sal,'L9,99,999.99') from emp;TO_CHAR(SAL,'L9,99,999----------------------

£800.00£1,600.00£1,250.00£2,975.00

For Negative values onlySQL > select To_Char(-4500,'999999MI') from dual;



TO_CHAR-------

4500-

SQL>select To_Char(-4500,'999999PR') from dual;

TO_CHAR(--------

<4500>

SQL> Select To_Char(4578456874,'9999EEEE') from dual;

TO_CHAR

-------5E+09

V Multiply by 10 n times ( n = number of 9s after V) 9999V99 123400SQL> Select To_Char(1234,'9999V99') from Dual;

TO_CHAR-------

123400

B - Display zero values as blank, not 0 B9999.99 1234.00SQL> select To_Char(0,'9B') from dual;

TO--

To_NumberSQL> Select To_Number('145') from dual;

TO_NUMBER('145')----------------

145

To_DateSQL> Select To_Date('19-Sep-2008') from dual;



TO_DATE('---------19-SEP-08

SQL> Select To_Date('25-Jul-1973') + 7 From dual;

TO_DATE('---------01-AUG-73

30-09-2008Displaying Data From Multiple Tables

Cartesian Products

When a join condition is invalid or omitted completely, the result is a Cartesian product, in which all combinations of rows are displayed. All rows in the firsttable are joined to all rows in the second table.A Cartesian product tends to generate a large number of rows, and the result israrely useful. You should always include a valid join condition in a WHEREclause, unless you have a specific need to combine all rows from all tables.Cartesian products are useful for some tests when you need to generate a largenumber of rows to simulate a reasonable amount of data.

Ex:

Sql>Select Ename,Dname From Emp,Dept;135 Rows Selected.. (27 x 5 Records)

Note: Cartesian Product occursSQL> Set Pause On;SQL> Set Pause “Press any key to Continue..”(Wait for each page)

To Avoid Cartesian Product..



SQL > Select Ename,emp.deptno,Dname from emp,deptwhere emp.deptno=dept.deptno;

ENAME DEPTNO DNAME---------- ---------- --------------SMITH 20 RESEARCHALLEN 30 SALESWARD 30 SALESJONES 20 RESEARCHMARTIN 30 SALESBLAKE 30 SALES

Note: If we use the common named columns then weuse the table name also as prefix. (emp.deptno)Note: Equijoins are also called simple joins or inner joins .

Using AND condition.SQL>Select Ename,emp.deptno,Dname from emp,deptwhere emp.deptno=dept.deptno AND dept.deptno=20;

ENAME DEPTNO DNAME---------- ---------- --------------SMITH 20 RESEARCH



JONES 20 RESEARCHSCOTT 20 RESEARCHADAMS 20 RESEARCH

Using Table AliasQualifying Ambiguous Column NamesYou need to qualify the names of the columns in the WHERE clause with the table name to avoidambiguity. Without the table prefixes, the DEPARTMENT_ID column could be from either theDEPARTMENTS table or the EMPLOYEES table. It is necessary to add the table prefix toexecute your query.

SQL> Select e.ename,e.job,e.sal,e.deptno,d.dname,d.loc from emp e,dept d where e.deptno=d.deptno;ENAME JOB SAL DEPTNO DNAME LOC---------- --------- ---------- ---------- -------------- -------------SMITH CLERK 800 20 RESEARCH DALLASALLEN SALESMAN 1600 30 SALES CHICAGOWARD SALESMAN 1250 30 SALES CHICAGOJONES MANAGER 2975 20 RESEARCH DALLASMARTIN SALESMAN 1250 30 SALES CHICAGO

SQL > Select e.ename,d.dname,l.name From emp e,deptd,location l where e.deptno=d.deptno andd.loc_id=l.loc_id



ENAME DNAME NAME---------- -------------- --------------------kannan ACCOUNTING EASTkannan ACCOUNTING EASTRaman ACCOUNTING EASTXX ACCOUNTING EASTSMITH RESEARCH WESTADAMS RESEARCH WESTFORD RESEARCH WEST

SQL >Select Distinct e.ename,d.dname,l.name From emp e,dept d,location l where e.deptno=d.deptno andd.loc_id=l.loc_id;

ENAME DNAME NAME---------- -------------- --------------------ADAMS RESEARCH WESTALLEN SALES SOUTHASHOK RESEARCH WESTBLAKE SALES SOUTHFORD RESEARCH WESTJAMES SALES SOUTHJONES RESEARCH WEST

Non-EquijoinsA non-equijoin is a join condition containing something other than an equality operator.The relationship between the EMPLOYEES table and the JOB_GRADES table has anexample of a non-equijoin. A relationship between the two tables is that the SALARYcolumn in the EMPLOYEES table must be between the values in the LOWEST_SALARYand HIGHEST_SALARY columns of the JOB_GRADES table. The relationship isobtained using an operator other than equals (=).

SQL> SELECT e.last_name, e.salary, j.grade_level2 FROM employees e, job_grades j3 WHERE e.salary4 BETWEEN j.lowest_sal AND j.highest_sal;

LAST_NAME SALARY GRA-------------------- ---------- ---Matos 2600 AVargas 2500 A



Lorentz 4200 BRajs 3500 BDavies 3100 BWhalen 4400 BHunold 9000 C

The slide example creates a non-equijoin to evaluate an employee’s salary grade. The salary must be between any pair of the low and high salary ranges.It is important to note that all employees appear exactly once when this query is executed. Noemployee is repeated in the list. There are two reasons for this:• None of the rows in the job grade table contain grades that overlap. That is, the salary value for an employee can lie only between the low salary and high salary values of one of the rows in thesalary grade table.• All of the employees’ salaries lie within the limits provided by the job grade table. That is, noemployee earns less than the lowest value contained in the LOWEST_SAL column or more thanthe highest value contained in the HIGHEST_SAL column.Note: Other conditions, such as <= and >= can be used, but BETWEEN is the simplest.Remember to specify the low value first and the high value last when using BETWEEN.Table aliases have been specified in the slide example for performance reasons, not because of

possible ambiguity.SQL> SELECT e.last_name, e.salary, j.grade_level FROM employeese, job_grades j WHERE e.salary >= j.lowest_sal AND e.salary <=j.highest_sal

LAST_NAME SALARY GRA-------------------- ---------- ---Matos 2600 AVargas 2500 ALorentz 4200 BRajs 3500 B



SQL > select ename,dept.deptno,dept.dname from emp,dept whereemp.deptno(+)=dept.deptno

ENAME DEPTNO DNAME---------- ---------- --------------kannan 10 ACCOUNTINGkannan 10 ACCOUNTINGBLAKE 30 SALESMARTIN 30 SALESJAMES 30 SALESTURNER 30 SALESWARD 30 SALESPRIYA 40 OPERATIONS

65 ADMINSQL>select ename,dept.deptno,dept.dname from emp,dept where

emp.deptno=dept.deptno(+)

ENAME DEPTNO DNAME---------- ---------- --------------

SMITH 20 RESEARCHADAMS 20 RESEARCHJAMES 30 SALESFORD 20 RESEARCH

10 ACCOUNTINGthekumarnithya1



Raman 20 RESEARCHRaman 10 ACCOUNTINGPRIYA 40 OPERATIONS

ENAME DEPTNO DNAME---------- ---------- --------------XX 10 ACCOUNTINGthe 20 RESEARCHSaranASHOK 20 RESEARCH

Ashok

SQL> edWrote file afiedt.buf

SQL > SELECT worker.last_name || ' works for '|| manager.last_name

FROM employees worker, employees managerWHERE worker.manager_id = manager.employee_id WORKER.LAST_NAME||'WORKSFOR'||MANAGER.LAST_NAME

---------------------------------------------------Kochhar works for KingDe Haan works for KingHaritstein works for KingZlotkey works for KingWhalen works for Kochhar



Higgins works for KochharHunold works for De HaanLorentz works for HunoldAbel works for ZlotkeyGrant works for ZlotkeyFay works for HaritsteinGietz works for Higgins

12 rows selected.03-Oct-2008

CROSS JOINSQL> Select Empno,Dept.deptno,Dname From Emp CROSS JOIN Dept;



EMPNO DEPTNO DNAME---------- ---------- --------------

7369 10 ACCOUNTING7499 10 ACCOUNTING

---- --100 65 ADMIN

5000 65 ADMIN145 65 ADMIN

135 rows selected.

ORSQL> Select Empno,Dept.Deptno,Dname From Emp,Dept;

NATURAL JOINSQL>Select Empno,Deptno,Ename,Dname From Emp NATURAL JOIN Dept

EMPNO DEPTNO ENAME DNAME

---------- ---------- ------------------------- --------------7369 20 SMITH RESEARCH7499 30 ALLEN SALES7521 30 WARD SALES7566 20 JONES RESEARCH7654 30 MARTIN SALES7698 30 BLAKE SALES4567 10 kannan ACCOUNTING7788 20 SCOTT RESEARCH4568 10 kannan ACCOUNTING7844 30 TURNER SALES7876 20 ADAMS RESEARCH7900 30 JAMES SALES7902 20 FORD RESEARCH

Using Where Clause in NATURAL JOINSQL>Select Empno,Deptno,Ename,Dname From Emp NATURAL JOIN DeptWhere Deptno in (20,40)

EMPNO DEPTNO ENAME DNAME--------- ---------- ------------------------------ ----------

7512 40 PRIYA OPERATIONS7369 20 SMITH RESEARCH7566 20 JONES RESEARCH7788 20 SCOTT RESEARCH

JOIN & USING (As like EQUI JOIN)SQL> Select e.ename,d.dname from emp e join dept d using(deptno);

ENAME DNAME------------------------------ --------------SMITH RESEARCHALLEN SALES



WARD SALESJONES RESEARCHMARTIN SALESBLAKE SALESkannan ACCOUNTINGSCOTT RESEARCH



LEFT OUTER JOIN



Instructor NoteIt was not possible to complete this in earlier releases using outer joins. However, you couldaccomplish the same results using the UNION operator.SELECT e.last_name, e.department_id, d.department_nameFROM employees e, departments dWHERE e.department_id (+) = d.department_idUNIONSELECT e.last_name, e.department_id, d.department_nameFROM employees e, departments dWHERE e.department_id = d.department_id (+);



Aggregating DataUsing Group Functions

Group FunctionsUnlike single-row functions, group functions operate on sets of rows to give one result per group.These sets may be the whole table or the table split into groups.









Groups of DataUntil now, all group functions have treated the table as one large group of information. At times,you need to divide the table of information into smaller groups. This can be done by using theGROUP BY clause.











Standard Deviation

SQL> select stddev(sal) from emp;

STDDEV(SAL)-----------

14044.1804

1 row selected.

SQL> select variance(sal) from emp;

VARIANCE(SAL)-------------

197239002

1 row selected.

04-Oct-2008

SubqueriesIn this lesson, you learn about more advanced features of the SELECT statement. You can writesubqueries in the WHERE clause of another SQL statement to obtain values based on an unknown

conditional value. This lesson covers single-row subqueries and multiple-row subqueries.







Note: The outer and inner queries can get data from different tables.











Multiple-Row Subqueries (continued)The ANY operator (and its synonym, the SOME operator) compares a value to each valuereturned by a subquery. The slide example displays employees who are not IT programmers andwhose salary is less than that of any IT programmer. The maximum salary that a programmer earns is $9,000.<ANY means less than the maximum. > ANY means more than the minimum. = ANY isequivalent to

IN .<ALL means less than the maximum. > ALL means more than the minimum



Multiple-Row Subqueries (continued)The ALL operator compares a value to every value returned by a subquery. The slide exampledisplaysemployees whose salary is less than the salary of all employees with a job ID of IT_PROG andwhose job is not IT_PROG.>ALL means more than the maximum, and <ALL means less than the minimum.The NOT operator can be used with IN , ANY, and ALL operators.



Manipulating Data







To create a Table from existing with record SQL> Create Table Dept_Dupe As Select * from Dept;

Table created.

To create a Table from existing with out record SQL> Create Table Dept_Dupe1 As Select * from Dept Where 0=1;

To insert RecordsSQL> Insert into Dept_Dupe1 Select * From Dept;

To a Particular ColumnSQL> Insert into Dept_Dupe1(Dname) Select Loc_Id from Dept;



6-Oct-2008

To change a name in the existing record?SQL> Update emp SET ENAME = 'ABISHEIK' where ename='kannan';

To Change in 2 columnsSQL> UPDATE EMP SET ENAME='THIRU',JOB='TECH' WHERE EMPNO=4569;

Update for 2 Emp numbersSQL> UPDATE EMP SET ENAME='PRASANTH',JOB='CONSULT' WHEREEMPNO=1254 OR EMPNO=1245;

To Change the salary as 1000 those who get Less than 1000SQL> Update emp set sal=1000 Where SAL < 1000;



Ex:SQL> Update Emp set Job = (Select Job from emp whereename='PRIYA'),Sal = (Select Sal from Emp WhereEname='PRIYA') Where Ename='ABISHEIK';



Ex:SQL> UPDATE EMP2 SET ENAME=(Select Ename From Emp WhereEmpno=4569) Where empno=4569;



EX:SQL> Truncate Table Departments;Truncate Table Departments

*ERROR at line 1:



ORA-02266: unique/primary keys in table referenced byenabled foreign keys

Ex:To delete a particular rowSQL>Delete From Emp2 Where Empno=1000;

To Delete all RowsSQL>Delete From Emp2;

Note: Rollback the Deleted Rows



Using INSQL>Delete From Emp Where Empno IN (145,100,1321,11111)

Ex:SQL> Delete From Emp Where Deptno = (Select deptno from dept where dname='OPERATIONS');







ID NAME DEPTNO---------- ------------------------- ----------

1000 PRASANTH 202000 ASHOK 20

3000 20SQL> UPDATE CIG_STAFF SET NAME=DEFAULT WHERE ID=1000;

1 row updated.

SQL> SELECT * FROM CIG_STAFF;

ID NAME DEPTNO---------- ------------------------- ----------

1000 202000 ASHOK 203000 20



Ex:SQL> Merge into copy_staff cs using cig_staff ot

2 on (cs.id = ot.id)3 When Matched then4 Update set cs.name = ot.name5 , cs.deptno=ot.deptno6 When Not Matched Then7 Insert values (ot.id,ot.name,ot.deptno);

5 rows merged.





Ex:SQL> commit;

Commit complete.

SQL> insert into copy_staff values(8000,'Saro',65);1 row created.

SQL> SavePoint A;

Savepoint created.

SQL> insert into copy_staff values(9000,'Seenu',75);

1 row created.

SQL> SavePoint B;

Savepoint created.

SQL> insert into copy_staff values(7500,'raja',85);

1 row created.

SQL> rollback to savepoint A;

Rollback complete.

SQL> select * from copy_staff;

ID NAME DEPTNO---------- ------------------------- ----------

1000 Saran 202000 ASHOK 203000 Saran 205000 Abishiek 604000 Thiru 508000 Saro 65

6 rows selected.

SQL> rollback;

Rollback complete.




ID NAME DEPTNO---------- ------------------------- ----------

1000 Saran 202000 ASHOK 20

3000 Saran 205000 Abishiek 604000 Thiru 50

SQL> delete from copy_staff;

5 rows deleted.

SQL> rollback;

Rollback complete.


ID NAME DEPTNO---------- ------------------------- ----------

1000 Saran 202000 ASHOK 203000 Saran 205000 Abishiek 604000 Thiru 50



11-Oct-08

Creating and Managing Tables





Ex:SQL>Select * From SCOTT.EMP;



Ex:SQL>CREATE TABLE STAFF(ENO NUMBER,ENAME VARCHAR2(25),DOJ DATE DEFAULT SYSDATE);



Ex:SQL> SELECT * FROM USER_TABLES;SQL> SELECT * FROM USER_VIEWS;SQL> SELECT * FROM USER_SYNONYMS;SQL> SELECT * FROM USER_SEQUENCES;

USE ALL_ SQL> SELECT * FROM ALL_TABLES;

SQL> SELECT * FROM ALL_VIEWS;























Ex:SQL> SELECT * FROM ALL_TAB_COMMENTS WHERE TABLE_NAME ='EMPLOYEES';

Including Constraints







Ex:Sql>CREATE TABLE CIG_CONS1(ID NUMBER,NAME VARCHAR2(15),NICK

VARCHAR2(10), CONSTRAINT CONS_1 UNIQUE(name,nick));



















ISQLPLUS



Note:If we give the value by “Define” then take that valueotherwise it asking for a value.

SQL>DEFINE TN=DEPT;SQL>SELECT * FROM &TN;











Note: SQL>SET VERIFY OFF; Now old & new are skipped.







Ex:







'Data in Thousands'

Monthly Analysis 01 Jan 2001 Page: 1Data in Thousands

To suppress the top title display without changing its definition, enter

TTITLE OFF

Ex:SQL>REPHEADER “WELCOME”SQL>REPFOOTER “GOOD BYE”

15-Oct-08

Creating Views

Ex:



SQL>create or replace view emp_view AS Select employee_number,ename,sal from emp;





SQL> SELECT * FROM CVIEW;

DEPTNO MINSAL MAXSAL AVGSAL---------- ---------- ---------- ----------

10 1000 3740 229020 1000 71500 11315.312530 1045 3135 1723.3333340 2200 2200 2200









•













16-Oct-08

Ex:SQL>ALTER SEQUENCE CIG_SEQ1 INCREMENT BY 5;



Ex:SQL> ALTER SEQUENCE CIG_SEQ1 MAXVALUE 50;ALTER SEQUENCE CIG_SEQ1 MAXVALUE 50*ERROR at line 1:ORA-04009: MAXVALUE cannot be made to be less thanthe current value

Ex:SQL> DROP SEQUENCE CIG_SEQ1;

Sequence dropped.









Let students know that to create a function-based index in your own schema on your own table,you must have the CREATE INDEX and QUERY REWRITE system privileges. To create theindex in another schema or on another schema’s table, you must have the CREATE ANY INDEX

and GLOBAL QUERY REWRITE privileges. The table owner must also have the EXECUTEobject privilege on the functions used in the function-based index.





Controlling User Access























NOPRINTTo hide a column upto the current sessionSQL>COLUMN ENAME NOPRINT;

Note: The column Ename is hidden;

17-Oct-08Oracle9 i Datetime Functions



To view all zonesSQL>Select * From V$TIMEZONE_NAMES;





















Note:If we use as like above , just eliminate the subtotals ofjobid wise.

















Ex:SQL> Update cor_emp e set dname = (Select dname from dept

where e.deptno=deptno);

29 rows updated.





Hierarchical Retrieval



























Documents

Easy SQL Practice