![3
3
3
Basic SELECT Statement
SELECT [DISTINCT] {*, column [alias],...}
FROM table;
• Select Clause determines what columns
• The From Clause determines which table.](https://image.slidesharecdn.com/3-250617094946-9f146197/85/Structure-query-language-Data-Query-language-for-beginners-pdf-3-320.jpg)
![15
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Defining Column Alias
• The Heading name is replaced for the
current SELECT Statement.
• AS Keyword [ Optional ] between the
column name and the actual alias name
• Double Quotation Marks.](https://image.slidesharecdn.com/3-250617094946-9f146197/85/Structure-query-language-Data-Query-language-for-beginners-pdf-15-320.jpg)
![22
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SQL*Plus Commands
–A[PPEND] text
–C[HANGE] / old / new
–C[HANGE] / text /
–CL[EAR] BUFF[ER]
–DEL
–DEL n
–DEL m n](https://image.slidesharecdn.com/3-250617094946-9f146197/85/Structure-query-language-Data-Query-language-for-beginners-pdf-22-320.jpg)
![24
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Summary
•Use SQL*Plus as an environment to:
–Execute SQL statements
–Edit SQL statements
SELECT [DISTINCT] {*,column[alias],...}
FROM table;](https://image.slidesharecdn.com/3-250617094946-9f146197/85/Structure-query-language-Data-Query-language-for-beginners-pdf-24-320.jpg)
![27
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Using ‘WHERE’ Clause
• Specify the Selection of rows retrieved by
the WHERE Clause.
• The WHERE clause follows the FROM
clause.
SELECT [DISTINCT] {*, column [alias], ...}
FROM table
[WHERE condition(s)];](https://image.slidesharecdn.com/3-250617094946-9f146197/85/Structure-query-language-Data-Query-language-for-beginners-pdf-27-320.jpg)
![47
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Summary
SELECT [DISTINCT] {*, column [alias], ...}
FROM table
[WHERE condition(s)]
[ORDER BY {column, expr, alias} [ASC|DESC]];](https://image.slidesharecdn.com/3-250617094946-9f146197/85/Structure-query-language-Data-Query-language-for-beginners-pdf-47-320.jpg)
Structure query language - Data Query language for beginners.pdf
- 2. 2 2 2 Objectives • SQL SELECT statements • A basic SELECT statement • SQL statements and SQL*Plus commands
- 3. 3 3 3 Basic SELECT Statement SELECT [DISTINCT] {*, column [alias],...} FROM table; • Select Clause determines what columns • The From Clause determines which table.
- 4. 4 4 4 Writing SQL Statements • SQL is not Case Sensitive. • Tabs and Indentations will promote readability. • Keywords cannot be split or abbreviated. • SQL Statements can be split across lines. • Clauses are placed in different lines, to promote readability.
- 5. 5 5 5 Selecting All Columns DEPTNO DNAME LOC --------- -------------- ------------- 10 ACCOUNTING NEW YORK 20 RESEARCH DALLAS 30 SALES CHICAGO 40 OPERATIONS BOSTON SQL> SELECT * 2 FROM departments;
- 6. 6 6 6 Selecting Specific Columns DEPTNO LOC --------- ------------- 10 NEW YORK 20 DALLAS 30 CHICAGO 40 BOSTON SQL> SELECT deptno, loc 2 FROM departments;
- 7. 7 7 7 Default Column Headings • Default justification • Date and Character Data is Left Justified • Numeric Data is Right Justified • Display Headings in UPPER CASE. • Alias name can be replaced by the column name.
- 8. 8 8 8 Arithmetic Expressions •Basic Arithmetic operators Operator + - * / Description Add Subtract Multiply Divide
- 9. 9 9 9 Using Arithmetic Operators SQL> SELECT ename, sal, sal+300 2 FROM employees; ENAME SAL SAL+300 ---------- --------- --------- KING 5000 5300 BLAKE 2850 3150 CLARK 2450 2750 JONES 2975 3275 MARTIN 1250 1550 ALLEN 1600 1900 ... 14 rows selected.
- 10. 10 10 10 Operator Precedence • Parentheses can force precedence • Multiplication and Division followed by Addition and subtraction. * / + _
- 11. 11 11 11 Operator Precedence SQL> SELECT ename, sal, 12*sal+100 2 FROM employees; ENAME SAL 12*SAL+100 ---------- --------- ---------- KING 5000 60100 BLAKE 2850 34300 CLARK 2450 29500 JONES 2975 35800 MARTIN 1250 15100 ALLEN 1600 19300 ... 14 rows selected.
- 12. 12 12 12 Using Parentheses SQL> SELECT ename, sal, 12*(sal+100) 2 FROM emp; ENAME SAL 12*(SAL+100) ---------- --------- ----------- KING 5000 61200 BLAKE 2850 35400 CLARK 2450 30600 JONES 2975 36900 MARTIN 1250 16200 ... 14 rows selected.
- 13. 13 13 13 Defining a Null Value • NULL is UNASSIGNED Value. SQL> SELECT ename, job, comm 2 FROM emp; ENAME JOB COMM ---------- --------- --------- KING PRESIDENT BLAKE MANAGER ... TURNER SALESMAN 0 ... 14 rows selected.
- 14. 14 14 14 Null Values in Arithmetic Expr • NULL as an operand will result NULL SQL> select ename NAME, 12*sal+comm 2 from emp 3 WHERE ename='KING'; NAME 12*SAL+COMM ---------- ----------- KING
- 15. 15 15 15 Defining Column Alias • The Heading name is replaced for the current SELECT Statement. • AS Keyword [ Optional ] between the column name and the actual alias name • Double Quotation Marks.
- 16. 16 16 16 Using Column Aliases SQL> SELECT ename AS name, sal salary 2 FROM employees; NAME SALARY ------------- --------- ... SQL> SELECT ename "Name", 2 sal*12 "Annual Salary" 3 FROM employees; Name Annual Salary ------------- ------------- ...
- 17. 17 17 17 Concatenation Operator (||) • Concatenates the Columns of any data type. • A Resultant column will be a Single column.
- 18. 18 18 18 Using Concatenation Operator SQL> SELECT ename||job AS "Employees" 2 FROM emp; Employees ------------------- KINGPRESIDENT BLAKEMANAGER CLARKMANAGER JONESMANAGER MARTINSALESMAN ALLENSALESMAN ... 14 rows selected.
- 19. 19 19 19 Literal Character Strings • Date and character literal values must be enclosed within single quotation marks.
- 20. 20 20 20 Using ‘DISTINCT’ Clause •Eliminate duplicate rows by using the DISTINCT keyword SQL> SELECT DISTINCT deptno 2 FROM emp; DEPTNO --------- 10 20 30
- 21. 21 21 21 SQL Vs SQL*Plus SQL • A language • Keyword cannot be abbreviated • Statements manipulate data and table definitions in the database • SQL statements are stored in buffer SQL*Plus • An environment • Keywords can be abbreviated • Commands do not allow manipulation of values in the database • SQL*PLUS statements are not stored in Buffer
- 22. 22 22 22 SQL*Plus Commands –A[PPEND] text –C[HANGE] / old / new –C[HANGE] / text / –CL[EAR] BUFF[ER] –DEL –DEL n –DEL m n
- 23. 23 23 23 SQL*Plus File Commands –SAVE filename –GET filename –START filename –EDIT filename
- 24. 24 24 24 Summary •Use SQL*Plus as an environment to: –Execute SQL statements –Edit SQL statements SELECT [DISTINCT] {*,column[alias],...} FROM table;
- 25. 25 25 25 Using 'Where' and 'Order By' Clauses
- 26. 26 26 26 Objectives • Limit the rows required • Arrange the rows in a particular order.
- 27. 27 27 27 Using ‘WHERE’ Clause • Specify the Selection of rows retrieved by the WHERE Clause. • The WHERE clause follows the FROM clause. SELECT [DISTINCT] {*, column [alias], ...} FROM table [WHERE condition(s)];
- 28. 28 28 28 Using WHERE Clause SQL> SELECT ename, job, deptno 2 FROM emp 3 WHERE job='CLERK'; ENAME JOB DEPTNO ---------- --------- --------- JAMES CLERK 30 SMITH CLERK 20 ADAMS CLERK 20 MILLER CLERK 10
- 29. 29 29 29 Character Strings and Dates • Character / Dates are Represented by the Single Quotation Marks. • Default date format is 'DD-MON-YY' SQL> SELECT ename, job, deptno 2 FROM emp 3 WHERE ename = 'JAMES';
- 30. 30 30 30 Comparison Operators Operator = > >= < <= <> Meaning Equal to Greater than Greater than or equal to Less than Less than or equal to Not equal to
- 31. 31 31 31 Using Comparison Operators SQL> SELECT ename, sal, comm 2 FROM emp 3 WHERE sal<=comm; ENAME SAL COMM ---------- --------- --------- MARTIN 1250 1400
- 32. 32 32 32 More Comparison Operators Operator BETWEEN ...AND... IN(list) LIKE IS NULL Meaning Between two values (inclusive) Match any of a list of values Match a character pattern Is a null value
- 33. 33 33 33 Using BETWEEN Operator ENAME SAL ---------- --------- MARTIN 1250 TURNER 1500 WARD 1250 ADAMS 1100 MILLER 1300 SQL> SELECT ename, sal 2 FROM emp 3 WHERE sal BETWEEN 1000 AND 1500; Lower limit Higher limit •Used to compare between range of values. Values Specified are inclusive.
- 34. 34 34 34 Using IN Operator •IN Operator to check with a List of Values. SQL> SELECT empno, ename, sal, mgr 2 FROM emp 3 WHERE mgr IN (7902, 7566, 7788); EMPNO ENAME SAL MGR --------- ---------- --------- --------- 7902 FORD 3000 7566 7369 SMITH 800 7902 7788 SCOTT 3000 7566 7876 ADAMS 1100 7788
- 35. 35 35 35 Using LIKE Operator • Like Keyword Does Wildcard Searches in Valid String Values.. % ---------- zero or many characters _ ----------- one character SQL> SELECT ename 2 FROM emp 3 WHERE ename LIKE 'S%';
- 36. 36 36 36 Using LIKE Operator • ESCAPE identifier to search for "%" or "_". SQL> SELECT ename 2 FROM emp 3 WHERE ename LIKE ‘_A%‘; ENAME ---------- JAMES WARD
- 37. 37 37 37 Using IS NULL Operator •To Check for Null Values , IS NULL is used. SQL> SELECT ename, mgr 2 FROM emp 3 WHERE mgr IS NULL; ENAME MGR ---------- --------- KING
- 38. 38 38 38 Logical Operators Operator AND OR NOT Meaning Returns TRUE if both component conditions are TRUE Returns TRUE if either component condition is TRUE Returns TRUE if the following condition is FALSE
- 39. 39 39 39 Using AND Operator •AND requires both conditions to be TRUE. SQL> SELECT empno, ename, job, sal 2 FROM emp 3 WHERE sal>=1100 4 AND job='CLERK'; EMPNO ENAME JOB SAL --------- ---------- --------- --------- 7876 ADAMS CLERK 1100 7934 MILLER CLERK 1300
- 40. 40 40 40 Using OR Operator • OR requires either condition to be TRUE. SQL> SELECT empno, ename, job, sal 2 FROM emp 3 WHERE sal>=1100 4 OR job='CLERK'; EMPNO ENAME JOB SAL --------- ---------- --------- --------- 7839 KING PRESIDENT 5000 7698 BLAKE MANAGER 2850 7782 CLARK MANAGER 2450 7566 JONES MANAGER 2975 7654 MARTIN SALESMAN 1250 ... 14 rows selected.
- 41. 41 41 41 Using NOT Operator SQL> SELECT ename, job 2 FROM emp 3 WHERE job NOT IN ('CLERK','MANAGER','ANALYST'); ENAME JOB ---------- --------- KING PRESIDENT MARTIN SALESMAN ALLEN SALESMAN TURNER SALESMAN WARD SALESMAN
- 42. 42 42 42 Rules of Precedence Order Evaluated Operator 1 All comparison operators 2 NOT 3 AND 4 OR
- 43. 43 43 43 ‘ORDER BY’ Clause • Sort rows specified by the order: ASC/DESC SQL> SELECT ename, job, deptno, hiredate 2 FROM emp 3 ORDER BY hiredate; ENAME JOB DEPTNO HIREDATE ---------- --------- --------- --------- SMITH CLERK 20 17-DEC-80 ALLEN SALESMAN 30 20-FEB-81 ... 14 rows selected.
- 44. 44 44 44 Sorting in Descending Order SQL> SELECT ename, job, deptno, hiredate 2 FROM emp 3 ORDER BY hiredate DESC; ENAME JOB DEPTNO HIREDATE ---------- --------- --------- --------- ADAMS CLERK 20 12-JAN-83 SCOTT ANALYST 20 09-DEC-82 MILLER CLERK 10 23-JAN-82 JAMES CLERK 30 03-DEC-81 FORD ANALYST 20 03-DEC-81 KING PRESIDENT 10 17-NOV-81 MARTIN SALESMAN 30 28-SEP-81 ... 14 rows selected.
- 45. 45 45 45 Sorting the rows by Alias SQL> SELECT empno, ename, sal*12 annsal 2 FROM emp 3 ORDER BY annsal; EMPNO ENAME ANNSAL --------- ---------- --------- 7369 SMITH 9600 7900 JAMES 11400 7876 ADAMS 13200 7654 MARTIN 15000 7521 WARD 15000 7934 MILLER 15600 7844 TURNER 18000 ... 14 rows selected.
- 46. 46 46 46 Sorting by Multiple Columns • The order of ORDER BY list is the order of sort. SQL> SELECT ename, deptno, sal 2 FROM emp 3 ORDER BY deptno, sal DESC; ENAME DEPTNO SAL ---------- --------- --------- KING 10 5000 CLARK 10 2450 MILLER 10 1300 FORD 20 3000 ... 14 rows selected.
- 47. 47 47 47 Summary SELECT [DISTINCT] {*, column [alias], ...} FROM table [WHERE condition(s)] [ORDER BY {column, expr, alias} [ASC|DESC]];