1Eyad Alshareef Enhanced Guide to Oracle 10g Chapter 3: Using SQL Queries to Insert, Update, Delete, and View Data

2Eyad Alshareef Writing Basic SQL Statements

3Eyad Alshareef ObjectivesObjectives After completing this lesson, you should be able to do the following: After completing this lesson, you should be able to do the following: List the capabilities of SQL SELECT statements List the capabilities of SQL SELECT statements Execute a basic SELECT statement Execute a basic SELECT statement After completing this lesson, you should be able to do the following: After completing this lesson, you should be able to do the following: List the capabilities of SQL SELECT statements List the capabilities of SQL SELECT statements Execute a basic SELECT statement Execute a basic SELECT statement

4Eyad Alshareef Capabilities of SQL SELECT Statements Selection Projection Table 1 Table 2 Table 1 Join

5Eyad Alshareef Basic SELECT Statement SELECT[DISTINCT] {*, column [alias],...} FROMtable; SELECT[DISTINCT] {*, column [alias],...} FROMtable; SELECT identifies what columns. SELECT identifies what columns. FROM identifies which table. FROM identifies which table. SELECT identifies what columns. SELECT identifies what columns. FROM identifies which table. FROM identifies which table.

6Eyad Alshareef Writing SQL Statements SQL statements are not case sensitive. SQL statements are not case sensitive. SQL statements can be on one or more lines. SQL statements can be on one or more lines. Keywords cannot be abbreviated or split across lines. Keywords cannot be abbreviated or split across lines. Clauses are usually placed on separate lines. Clauses are usually placed on separate lines. Tabs and indents are used to enhance readability. Tabs and indents are used to enhance readability. SQL statements are not case sensitive. SQL statements are not case sensitive. SQL statements can be on one or more lines. SQL statements can be on one or more lines. Keywords cannot be abbreviated or split across lines. Keywords cannot be abbreviated or split across lines. Clauses are usually placed on separate lines. Clauses are usually placed on separate lines. Tabs and indents are used to enhance readability. Tabs and indents are used to enhance readability.

7Eyad Alshareef Selecting All Columns DEPTNO DNAME LOC ACCOUNTING NEW YORK 20 RESEARCH DALLAS 30 SALES CHICAGO 40 OPERATIONS BOSTON SQL> SELECT * 2 FROM dept;

8Eyad Alshareef Selecting Specific Columns DEPTNO LOC NEW YORK 20 DALLAS 30 CHICAGO 40 BOSTON SQL> SELECT deptno, loc 2 FROM dept;

9Eyad Alshareef Qualifying Table Names If you retrieve data from a table that is owned by another user, you must qualify the table name by prefacing it with the owner’s name If you retrieve data from a table that is owned by another user, you must qualify the table name by prefacing it with the owner’s name

10Eyad Alshareef Column Heading Defaults Default justification Default justification Left: Date and character data Left: Date and character data Right: Numeric data Right: Numeric data Default display: Uppercase Default display: Uppercase Default justification Default justification Left: Date and character data Left: Date and character data Right: Numeric data Right: Numeric data Default display: Uppercase Default display: Uppercase

11Eyad Alshareef Arithmetic Expressions Create expressions on NUMBER and DATE data by using arithmetic operators. Create expressions on NUMBER and DATE data by using arithmetic operators. Operator + - * / Description Add Subtract Multiply Divide

12Eyad Alshareef Using Arithmetic Operators SQL> SELECT ename, sal, sal FROMemp; ENAME SAL SAL KING BLAKE CLARK JONES MARTIN ALLEN rows selected.

13Eyad Alshareef Operator Precedence Multiplication and division take priority over addition and subtraction. Multiplication and division take priority over addition and subtraction. Operators of the same priority are evaluated from left to right. Operators of the same priority are evaluated from left to right. Parentheses are used to force prioritized evaluation and to clarify statements. Parentheses are used to force prioritized evaluation and to clarify statements. Multiplication and division take priority over addition and subtraction. Multiplication and division take priority over addition and subtraction. Operators of the same priority are evaluated from left to right. Operators of the same priority are evaluated from left to right. Parentheses are used to force prioritized evaluation and to clarify statements. Parentheses are used to force prioritized evaluation and to clarify statements. ** //++__

14Eyad Alshareef Operator Precedence SQL> SELECT ename, sal, 12*sal FROM emp; ENAME SAL 12*SAL KING BLAKE CLARK JONES MARTIN ALLEN rows selected.

15Eyad Alshareef Using Parentheses SQL> SELECT ename, sal, 12*(sal+100) 2 FROM emp; ENAME SAL 12*(SAL+100) KING BLAKE CLARK JONES MARTIN rows selected.

16Eyad Alshareef Defining a Null Value A null is a value that is unavailable, unassigned, unknown, or inapplicable. A null is a value that is unavailable, unassigned, unknown, or inapplicable. A null is not the same as zero or a blank space. A null is not the same as zero or a blank space. A null is a value that is unavailable, unassigned, unknown, or inapplicable. A null is a value that is unavailable, unassigned, unknown, or inapplicable. A null is not the same as zero or a blank space. A null is not the same as zero or a blank space. ENAME JOB SAL COMM KING PRESIDENT 5000 BLAKE MANAGER TURNER SALESMAN rows selected. SQL> SELECT ename, job, sal, comm 2 FROM emp;

17Eyad Alshareef Null Values in Arithmetic Expressions Arithmetic expressions containing a null value evaluate to null. Arithmetic expressions containing a null value evaluate to null. SQL> select ename, 12*sal+comm 2 from emp 3 WHERE ename='KING'; ENAME 12*SAL+COMM KING

18Eyad Alshareef Defining a Column Alias Renames a column heading Renames a column heading Is useful with calculations Is useful with calculations Immediately follows column name; optional AS keyword between column name and alias Immediately follows column name; optional AS keyword between column name and alias Requires double quotation marks if it contains spaces or special characters or is case sensitive Requires double quotation marks if it contains spaces or special characters or is case sensitive Renames a column heading Renames a column heading Is useful with calculations Is useful with calculations Immediately follows column name; optional AS keyword between column name and alias Immediately follows column name; optional AS keyword between column name and alias Requires double quotation marks if it contains spaces or special characters or is case sensitive Requires double quotation marks if it contains spaces or special characters or is case sensitive

19Eyad Alshareef Using Column Aliases SQL> SELECT ename AS name, sal salary 2 FROM emp; NAME SALARY SQL> SELECT ename "Name", 2 sal*12 "Annual Salary" 3 FROM emp; Name Annual Salary

20Eyad Alshareef Concatenation Operator Concatenates columns or character strings to other columns Concatenates columns or character strings to other columns Is represented by two vertical bars (||) Is represented by two vertical bars (||) Creates a resultant column that is a character expression Creates a resultant column that is a character expression Concatenates columns or character strings to other columns Concatenates columns or character strings to other columns Is represented by two vertical bars (||) Is represented by two vertical bars (||) Creates a resultant column that is a character expression Creates a resultant column that is a character expression

21Eyad Alshareef Using the Concatenation Operator SQL> SELECTename||job AS "Employees" 2 FROM emp; Employees KINGPRESIDENT BLAKEMANAGER CLARKMANAGER JONESMANAGER MARTINSALESMAN ALLENSALESMAN rows selected.

22Eyad Alshareef Literal Character Strings A literal is a character, a number, or a date included in the SELECT list. A literal is a character, a number, or a date included in the SELECT list. Date and character literal values must be enclosed within single quotation marks. Date and character literal values must be enclosed within single quotation marks. Each character string is output once for each row returned. Each character string is output once for each row returned. A literal is a character, a number, or a date included in the SELECT list. A literal is a character, a number, or a date included in the SELECT list. Date and character literal values must be enclosed within single quotation marks. Date and character literal values must be enclosed within single quotation marks. Each character string is output once for each row returned. Each character string is output once for each row returned.

23Eyad Alshareef Using Literal Character Strings Employee Details KING is a PRESIDENT BLAKE is a MANAGER CLARK is a MANAGER JONES is a MANAGER MARTIN is a SALESMAN rows selected. Employee Details KING is a PRESIDENT BLAKE is a MANAGER CLARK is a MANAGER JONES is a MANAGER MARTIN is a SALESMAN rows selected. SQL> SELECT ename||' is a '||job 2 AS "Employee Details" 3 FROM emp;

24Eyad Alshareef Duplicate Rows The default display of queries is all rows, including duplicate rows. The default display of queries is all rows, including duplicate rows. SQL> SELECT deptno 2 FROM emp; SQL> SELECT deptno 2 FROM emp; DEPTNO rows selected.

25Eyad Alshareef Eliminating Duplicate Rows Eliminate duplicate rows by using the DISTINCT keyword in the SELECT clause. SQL> SELECT DISTINCT deptno 2 FROM emp; DEPTNO

26Eyad Alshareef Restricting and Sorting Data

27Eyad Alshareef ObjectivesObjectives After completing this lesson, you should be able to do the following: After completing this lesson, you should be able to do the following: Limit the rows retrieved by a query Limit the rows retrieved by a query Sort the rows retrieved by a query Sort the rows retrieved by a query After completing this lesson, you should be able to do the following: After completing this lesson, you should be able to do the following: Limit the rows retrieved by a query Limit the rows retrieved by a query Sort the rows retrieved by a query Sort the rows retrieved by a query

28Eyad Alshareef Limiting Rows Using a Selection "…retrieve all employees in department 10" EMP EMPNO ENAME JOB... DEPTNO 7839KINGPRESIDENT BLAKEMANAGER CLARKMANAGER JONESMANAGER EMP EMPNO ENAME JOB... DEPTNO 7839KINGPRESIDENT CLARKMANAGER MILLERCLERK 10

29Eyad Alshareef Limiting Rows Selected Restrict the rows returned by using the WHERE clause. Restrict the rows returned by using the WHERE clause. The WHERE clause follows the FROM clause. The WHERE clause follows the FROM clause. Restrict the rows returned by using the WHERE clause. Restrict the rows returned by using the WHERE clause. The WHERE clause follows the FROM clause. The WHERE clause follows the FROM clause. SELECT[DISTINCT] {*| column [alias],...} FROM table [WHEREcondition(s)];

30Eyad Alshareef Using the 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

31Eyad Alshareef Character Strings and Dates Character strings and date values are enclosed in single quotation marks. Character strings and date values are enclosed in single quotation marks. Character values are case sensitive and date values are format sensitive. Character values are case sensitive and date values are format sensitive. The default date format is DD-MON-YY. The default date format is DD-MON-YY. Character strings and date values are enclosed in single quotation marks. Character strings and date values are enclosed in single quotation marks. Character values are case sensitive and date values are format sensitive. Character values are case sensitive and date values are format sensitive. The default date format is DD-MON-YY. The default date format is DD-MON-YY. SQL> SELECTename, job, deptno 2 FROM emp 3 WHEREename = ; SQL> SELECTename, job, deptno 2 FROM emp 3 WHEREename = ; 'JAMES'

32Eyad Alshareef Comparison Operators Operator = > >= < <= <>, !=, ^= Meaning Equal to Greater than Greater than or equal to Less than Less than or equal to Not equal to

33Eyad Alshareef Using the Comparison Operators SQL> SELECT ename, sal, comm 2 FROM emp 3 WHERE sal<=comm; ENAME SAL COMM MARTIN

34Eyad Alshareef Other 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

35Eyad Alshareef Using the BETWEEN Operator ENAME SAL MARTIN 1250 TURNER 1500 WARD 1250 ADAMS 1100 MILLER 1300 SQL> SELECTename, sal 2 FROM emp 3 WHEREsal BETWEEN 1000 AND 1500; Lower limit Higher limit Use the BETWEEN operator to display rows based on a range of values. Use the BETWEEN operator to display rows based on a range of values.

36Eyad Alshareef Using the IN Operator Use the IN operator to test for values in a list. Use the IN operator to test for values in a list. SQL> SELECTempno, ename, sal, mgr 2 FROM emp 3 WHEREmgr IN (7902, 7566, 7788); EMPNO ENAME SAL MGR FORD SMITH SCOTT ADAMS

37Eyad Alshareef Using the LIKE Operator Use the LIKE operator to perform wildcard searches of valid search string values. Search conditions can contain either literal characters or numbers. – % denotes zero or many characters. – _ denotes one character. Use the LIKE operator to perform wildcard searches of valid search string values. Search conditions can contain either literal characters or numbers. – % denotes zero or many characters. – _ denotes one character. SQL> SELECTename 2 FROM emp 3 WHEREename LIKE 'S%';

38Eyad Alshareef Using the LIKE Operator You can combine pattern-matching characters. You can combine pattern-matching characters. SQL> SELECTename 2 FROMemp 3 WHEREename LIKE '_A%'; ENAME MARTIN JAMES WARD

39Eyad Alshareef Using the IS NULL Operator Test for null values with the IS NULL operator. Test for null values with the IS NULL operator. SQL> SELECT ename, mgr 2 FROM emp 3 WHERE mgr IS NULL; ENAME MGR KING

40Eyad Alshareef 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

41Eyad Alshareef Using the AND Operator AND requires both conditions to be TRUE. SQL> SELECT empno, ename, job, sal 2 FROM emp 3 WHERE sal>= AND job='CLERK'; EMPNO ENAME JOB SAL ADAMS CLERK MILLER CLERK 1300

42Eyad Alshareef Using the OR Operator OR requires either condition to be TRUE. SQL> SELECT empno, ename, job, sal 2 FROM emp 3 WHERE sal>= OR job='CLERK'; EMPNO ENAME JOB SAL KING PRESIDENT BLAKE MANAGER CLARK MANAGER JONES MANAGER MARTIN SALESMAN JAMES CLERK rows selected.

43Eyad Alshareef Using the 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

44Eyad Alshareef Rules of Precedence Override rules of precedence by using parentheses. Override rules of precedence by using parentheses. Order EvaluatedOperator 1All comparison operators 2NOT 3AND 4OR

45Eyad Alshareef Rules of Precedence ENAME JOB SAL KING PRESIDENT 5000 MARTIN SALESMAN 1250 ALLEN SALESMAN 1600 TURNER SALESMAN 1500 WARD SALESMAN 1250 ENAME JOB SAL KING PRESIDENT 5000 MARTIN SALESMAN 1250 ALLEN SALESMAN 1600 TURNER SALESMAN 1500 WARD SALESMAN 1250 SQL> SELECT ename, job, sal 2 FROM emp 3 WHERE job='SALESMAN' 4 OR job='PRESIDENT' 5 AND sal>1500;

46Eyad Alshareef Rules of Precedence ENAME JOB SAL KING PRESIDENT 5000 ALLEN SALESMAN 1600 ENAME JOB SAL KING PRESIDENT 5000 ALLEN SALESMAN 1600 Use parentheses to force priority. SQL> SELECT ename, job, sal 2 FROM emp 3 WHERE (job='SALESMAN' 4 OR job='PRESIDENT') 5 AND sal>1500;

47Eyad Alshareef ORDER BY Clause Sort rows with the ORDER BY clause Sort rows with the ORDER BY clause ASC: ascending order, default ASC: ascending order, default DESC: descending order DESC: descending order The ORDER BY clause comes last in the SELECT statement. The ORDER BY clause comes last in the SELECT statement. Sort rows with the ORDER BY clause Sort rows with the ORDER BY clause ASC: ascending order, default ASC: ascending order, default DESC: descending order DESC: descending order The ORDER BY clause comes last in the SELECT statement. The ORDER BY clause comes last in the SELECT statement. SQL> SELECT ename, job, deptno, hiredate 2 FROM emp 3 ORDER BY hiredate; ENAME JOB DEPTNO HIREDATE SMITH CLERK DEC-80 ALLEN SALESMAN FEB rows selected.

48Eyad Alshareef  Default sort order  Numerical: ascending  Character: A - Z  Date: oldest - newest  To force the sort order: use ASC or DESC  Example SELECT s_name, s_age FROM my_students ORDER BY s_age DESC; Sorting Query Data

49Eyad Alshareef Sorting in Descending Order SQL> SELECT ename, job, deptno, hiredate 2 FROM emp 3 ORDER BY hiredate DESC; ENAME JOB DEPTNO HIREDATE ADAMS CLERK JAN-83 SCOTT ANALYST DEC-82 MILLER CLERK JAN-82 JAMES CLERK DEC-81 FORD ANALYST DEC-81 KING PRESIDENT NOV-81 MARTIN SALESMAN SEP rows selected.

50Eyad Alshareef Sorting by Column Alias SQL> SELECT empno, ename, sal*12 annsal 2 FROM emp 3 ORDER BY annsal; EMPNO ENAME ANNSAL SMITH JAMES ADAMS MARTIN WARD MILLER TURNER rows selected.

51Eyad Alshareef Sorting by Multiple Columns The order of ORDER BY list is the order of sort. The order of ORDER BY list is the order of sort. You can sort by a column that is not in the SELECT list. SQL> SELECT ename, deptno, sal 2 FROM emp 3 ORDER BY deptno, sal DESC; ENAME DEPTNO SAL KING CLARK MILLER FORD rows selected.

52Eyad Alshareef SummarySummary SELECT[DISTINCT] {*| column [alias],...} FROM table [WHEREcondition(s)] [ORDER BY{column, expr, alias} [ASC|DESC]];