1. 2009.10.06 - SLIDE 1IS 257 – Fall 2009 SQL and Client Applications University of California, Berkeley School of Information IS 257: Database Management

2. 2009.10.06 - SLIDE 2IS 257 – Fall 2009 Lecture Outline Review –Relational Operations –Relational Algebra –Relational Calculus –Introduction to SQL Introduction to SQL and MySQL Application Development in Access

3. 2009.10.06 - SLIDE 3IS 257 – Fall 2009 Lecture Outline Review –Relational Operations –Relational Algebra –Relational Calculus –Introduction to SQL Introduction to SQL and MySQL (continued) Application Development in Access

4. 2009.10.06 - SLIDE 4IS 257 – Fall 2009 Relational Algebra Operations Select Project Product Union Intersect Difference Join Divide

5. 2009.10.06 - SLIDE 5IS 257 – Fall 2009 Select Extracts specified tuples (rows) from a specified relation (table).

6. 2009.10.06 - SLIDE 6IS 257 – Fall 2009 Project Extracts specified attributes(columns) from a specified relation.

7. 2009.10.06 - SLIDE 7IS 257 – Fall 2009 Join Builds a relation from two specified relations consisting of all possible concatenated pairs, one from each of the two relations, such that in each pair the two tuples satisfy some condition. (E.g., equal values in a given col.) A1 B1 A2 B1 A3 B2 B1 C1 B2 C2 B3 C3 A1 B1 C1 A2 B1 C1 A3 B2 C2 (Natural or Inner) Join

8. 2009.10.06 - SLIDE 8IS 257 – Fall 2009 Outer Join Outer Joins are similar to PRODUCT -- but will leave NULLs for any row in the first table with no corresponding rows in the second. A1 B1 A2 B1 A3 B2 A4 B7 B1 C1 B2 C2 B3 C3 A1 B1 C1 A2 B1 C1 A3 B2 C2 A4 * * Outer Join

9. 2009.10.06 - SLIDE 9IS 257 – Fall 2009 Join Items

10. 2009.10.06 - SLIDE 10IS 257 – Fall 2009 Relational Algebra What is the name of the customer who ordered Large Red Widgets? –Select “large Red Widgets” from Part as temp1 –Join temp1 with Line-item on Part # as temp2 –Join temp2 with Invoice on Invoice # as temp3 –Join temp3 with customer on cust # as temp4 –Project Name from temp4

11. 2009.10.06 - SLIDE 11IS 257 – Fall 2009 Relational Calculus Relational Algebra provides a set of explicit operations (select, project, join, etc) that can be used to build some desired relation from the database. Relational Calculus provides a notation for formulating the definition of that desired relation in terms of the relations in the database without explicitly stating the operations to be performed SQL is based on the relational calculus.

12. 2009.10.06 - SLIDE 12IS 257 – Fall 2009 SQL - History Structured Query Language SEQUEL from IBM San Jose ANSI 1992 Standard is the version used by most DBMS today (SQL92) Basic language is standardized across relational DBMSs. Each system may have proprietary extensions to standard.

13. 2009.10.06 - SLIDE 13IS 257 – Fall 2009 Lecture Outline Review –Relational Operations –Relational Algebra –Relational Calculus –Introduction to SQL Introduction to SQL (continued) Application Development in Access

14. 2009.10.06 - SLIDE 14IS 257 – Fall 2009 SQL Uses Database Definition and Querying –Can be used as an interactive query language –Can be imbedded in programs Relational Calculus combines Select, Project and Join operations in a single command: SELECT

15. 2009.10.06 - SLIDE 15IS 257 – Fall 2009 SELECT Syntax: –SELECT [DISTINCT] attr1, attr2,…, attr3 FROM rel1 r1, rel2 r2,… rel3 r3 WHERE condition1 {AND | OR} condition2 ORDER BY attr1 [DESC], attr3 [DESC]

16. 2009.10.06 - SLIDE 16IS 257 – Fall 2009 SELECT Syntax: –SELECT a.author, b.title FROM authors a, bibfile b, au_bib c WHERE a.AU_ID = c.AU_ID and c.accno = b.accno ORDER BY a.author ; Examples in Access...

17. 2009.10.06 - SLIDE 17IS 257 – Fall 2009 SELECT Conditions = equal to a particular value >= greater than or equal to a particular value > greater than a particular value <= less than or equal to a particular value <> not equal to a particular value LIKE “*term*” (may be other wild cards in other systems) IN (“opt1”, “opt2”,…,”optn”) BETWEEN val1 AND val2 IS NULL

18. 2009.10.06 - SLIDE 18IS 257 – Fall 2009 Relational Algebra Selection using SELECT Syntax: –SELECT * FROM rel1 WHERE condition1 {AND | OR} condition2;

19. 2009.10.06 - SLIDE 19IS 257 – Fall 2009 Relational Algebra Projection using SELECT Syntax: –SELECT [DISTINCT] attr1, attr2,…, attr3 FROM rel1 r1, rel2 r2,… rel3 r3;

20. 2009.10.06 - SLIDE 20IS 257 – Fall 2009 Relational Algebra Join using SELECT Syntax: –SELECT * FROM rel1 r1, rel2 r2 WHERE r1.linkattr = r2.linkattr ;

21. 2009.10.06 - SLIDE 21IS 257 – Fall 2009 Sorting SELECT BIOLIFE.[Common Name], BIOLIFE.[Length (cm)] FROM BIOLIFE ORDER BY BIOLIFE.[Length (cm)] DESC; Note: the square brackets are not part of the standard, But are used in Access for names with embedded blanks

22. 2009.10.06 - SLIDE 22IS 257 – Fall 2009 Subqueries SELECT SITES.[Site Name], SITES.[Destination no] FROM SITES WHERE sites.[Destination no] IN (SELECT [Destination no] from DEST where [avg temp (f)] >= 78); Can be used as a form of JOIN.

23. 2009.10.06 - SLIDE 23IS 257 – Fall 2009 Aggregate Functions Count Avg SUM MAX MIN Others may be available in different systems

24. 2009.10.06 - SLIDE 24IS 257 – Fall 2009 Using Aggregate functions SELECT attr1, Sum(attr2) AS name FROM tab1, tab2... GROUP BY attr1, attr3 HAVING condition;

25. 2009.10.06 - SLIDE 25IS 257 – Fall 2009 Using an Aggregate Function SELECT DIVECUST.Name, Sum([Price]*[qty]) AS Total FROM (DIVECUST INNER JOIN DIVEORDS ON DIVECUST.[Customer No] = DIVEORDS.[Customer No]) INNER JOIN DIVEITEM ON DIVEORDS.[Order No] = DIVEITEM.[Order No] GROUP BY DIVECUST.Name HAVING (((DIVECUST.Name) Like "*Jazdzewski"));

26. 2009.10.06 - SLIDE 26IS 257 – Fall 2009 GROUP BY SELECT DEST.[Destination Name], Count(*) AS Expr1 FROM DEST INNER JOIN DIVEORDS ON DEST.[Destination Name] = DIVEORDS.Destination GROUP BY DEST.[Destination Name] HAVING ((Count(*))>1); Provides a list of Destinations with the number of orders going to that destination

27. 2009.10.06 - SLIDE 27IS 257 – Fall 2009 Lecture Outline Review –Relational Operations –Relational Algebra –Relational Calculus –Introduction to SQL Introduction to SQL and MySQL (continued) Application Development in Access

28. 2009.10.06 - SLIDE 28IS 257 – Fall 2009 MySQL The tag-line at http://www.mysql.com is –The world's most popular open source database It is true, it is the most widely used open source database system with users and uses that range from individuals to major corporations and includes… –Evite –Friend Finder Network –Friendster –Google (not for search though ) –PriceGrabber.com –Ticketmaster – Yahoo! –The US Census bureau –and many, many others

29. 2009.10.06 - SLIDE 29IS 257 – Fall 2009 MySQL myths The MySQL.com web site contains a list of common myths and misconceptions about MySQL and refutes them: –MYTH: MySQL is a new, untested database management system –MYTH: MySQL doesn’t support transactions like other proprietary database engines (it is supposed to be in the version we use here) –MYTH: MySQL is only for small, departmental, or web-based applications –MYTH: MySQL doesn’t offer enterprise-class features –MYTH: MySQL doesn’t have the type of support large corporations need –MYTH: MySQL isn’t open source any more

30. 2009.10.06 - SLIDE 30IS 257 – Fall 2009 MySQL documentation MySQL is available for download from MySQL.com In addition that site has complete online documentation for the MySQL system and for the mysql client program in their ‘Developer Zone’ –The online manuals are quite readable and have lot of examples to help you

31. 2009.10.06 - SLIDE 31IS 257 – Fall 2009 SQL Commands Data Definition Statements –For creation of relations/tables…

32. 2009.10.06 - SLIDE 32IS 257 – Fall 2009 CREATE Table CREATE TABLE table-name (col_name1 col_definition1 [PRIMARY KEY], col_name2 col_definition2,…,col_nameN col_definitionN); Adds a new table with the specified attributes (and types) to the database.

33. 2009.10.06 - SLIDE 33IS 257 – Fall 2009 Access Data Types (Not MySQL) Numeric (1, 2, 4, 8 bytes, fixed or float) Text (255 max) Memo (64000 max) Date/Time (8 bytes) Currency (8 bytes, 15 digits + 4 digits decimal) Autonumber (4 bytes) Yes/No (1 bit) OLE (limited only by disk space) Hyperlinks (up to 64000 chars)

34. 2009.10.06 - SLIDE 34IS 257 – Fall 2009 Access Numeric types Byte –Stores numbers from 0 to 255 (no fractions). 1 byte Integer – Stores numbers from –32,768 to 32,767 (no fractions) 2 bytes Long Integer(Default) –Stores numbers from –2,147,483,648 to 2,147,483,647 (no fractions). 4 bytes Single –Stores numbers from -3.402823E38 to –1.401298E–45 for negative values and from 1.401298E–45 to 3.402823E38 for positive values.4 bytes Double –Stores numbers from –1.79769313486231E308 to – 4.94065645841247E–324 for negative values and from 1.79769313486231E308 to 4.94065645841247E–324 for positive values.158 bytes Replication ID –Globally unique identifier (GUID)N/A16 bytes

35. 2009.10.06 - SLIDE 35IS 257 – Fall 2009 MySQL Data Types MySQL supports all of the standard SQL numeric data types. These types include the exact numeric data types (INTEGER, SMALLINT, DECIMAL, and NUMERIC), as well as the approximate numeric data types (FLOAT, REAL, and DOUBLE PRECISION). The keyword INT is a synonym for INTEGER, and the keyword DEC is a synonym for DECIMAL Numeric (can also be declared as UNSIGNED) –TINYINT (1 byte) –SMALLINT (2 bytes) –MEDIUMINT (3 bytes) –INT (4 bytes) –BIGINT (8 bytes) –NUMERIC or DECIMAL –FLOAT –DOUBLE (or DOUBLE PRECISION)

36. 2009.10.06 - SLIDE 36IS 257 – Fall 2009 MySQL Data Types The date and time types for representing temporal values are DATETIME, DATE, TIMESTAMP, TIME, and YEAR. Each temporal type has a range of legal values, as well as a “zero” value that is used when you specify an illegal value that MySQL cannot represent –DATETIME '0000-00-00 00:00:00' –DATE '0000-00-00' –TIMESTAMP (4.1 and up) '0000-00-00 00:00:00' –TIMESTAMP (before 4.1) 00000000000000 –TIME '00:00:00' –YEAR 0000

37. 2009.10.06 - SLIDE 37IS 257 – Fall 2009 MySQL Data Types The string types are CHAR, VARCHAR, BINARY, VARBINARY, BLOB, TEXT, ENUM, and SET Maximum length for CHAR and VARCHAR is 255 For longer things there is BLOB and TEXT

38. 2009.10.06 - SLIDE 38IS 257 – Fall 2009 MySQL Data Types A BLOB is a binary large object that can hold a variable amount of data. The four BLOB types are TINYBLOB, BLOB, MEDIUMBLOB, and LONGBLOB. These differ only in the maximum length of the values they can hold The four TEXT types are TINYTEXT, TEXT, MEDIUMTEXT, and LONGTEXT. These correspond to the four BLOB types and have the same maximum lengths and storage requirements TINY=1byte, BLOB and TEXT=2bytes, MEDIUM=3bytes, LONG=4bytes

39. 2009.10.06 - SLIDE 39IS 257 – Fall 2009 MySQL Data Types BINARY and VARBINARY are like CHAR and VARCHAR but are intended for binary data of 255 bytes or less ENUM is a list of values that are stored as their addresses in the list –For example, a column specified as ENUM('one', 'two', 'three') can have any of the values shown here. The index of each value is also shown: Value = Index NULL = NULL ‘’ = 0 'one’ = 1 ‘two’ = 2 ‘three’ = 3 –An enumeration can have a maximum of 65,535 elements.

40. 2009.10.06 - SLIDE 40IS 257 – Fall 2009 MySQL Data Types The final string type (for this version) is a SET A SET is a string object that can have zero or more values, each of which must be chosen from a list of allowed values specified when the table is created. SET column values that consist of multiple set members are specified with members separated by commas (‘,’) For example, a column specified as SET('one', 'two') NOT NULL can have any of these values: –'' –'one' –'two' –'one,two‘ A set can have up to 64 member values and is stored as an 8byte number

41. 2009.10.06 - SLIDE 41IS 257 – Fall 2009 ALTER Table ALTER TABLE table-name ADD COLUMN col_name col_definition; … DROP COLUMN col_name; … CHANGE col_name new_col_definition; Adds/removes a new column from an existing database table Many other options for adding constraints (like NOT NULL, or PRIMARY KEY), etc.

42. 2009.10.06 - SLIDE 42IS 257 – Fall 2009 INSERT INSERT INTO table-name (attr1, attr4, attr5,…, attrK) VALUES (“val1”, val4, val5,…, “valK”); Adds a new row(s) to a table. INSERT INTO table-name (attr1, attr4, attr5,…, attrK) VALUES SELECT...

43. 2009.10.06 - SLIDE 43IS 257 – Fall 2009 Creating a new table data from existing tables Syntax: –INSERT INTO tablename (attr1, attr2, attr3) SELECT [DISTINCT] xattr1, xattr2, xattr3 FROM rel1 r1, rel2 r2,… rel3 r3 WHERE condition1 {AND | OR} condition2 ORDER BY attr1 [DESC], attr3 [DESC] tablename has to previously exist for this to work in MySQL…

44. 2009.10.06 - SLIDE 44IS 257 – Fall 2009 DELETE DELETE FROM table-name WHERE ; Removes rows from a table.

45. 2009.10.06 - SLIDE 45IS 257 – Fall 2009 UPDATE UPDATE tablename SET attr1=newval, attr2 = newval2 WHERE ; changes values in existing rows in a table (those that match the WHERE clause).

46. 2009.10.06 - SLIDE 46IS 257 – Fall 2009 DROP Table DROP TABLE tablename; Removes a table from the database.

47. 2009.10.06 - SLIDE 47IS 257 – Fall 2009 CREATE INDEX CREATE [ UNIQUE|FULLTEXT|SPATIAL ] INDEX indexname indextype ON tablename (attr1 [ASC|DESC][, attr2 [ASC|DESC],...]) [USING [BTREE|HASH|RTREE]]

48. 2009.10.06 - SLIDE 48IS 257 – Fall 2009 MySQL Demo MySQL is on “Harbinger” AKA “people” Setup via My.SIMS Unix command for interactive use is ‘mysql’ which needs to include ‘-p’ to be prompted for the password, and optionally includes your database name, e.g.: –mysql –p ray Note that the version on Dream is not the latest – it is currently V. 5.0.45, latest is 6.0

49. 2009.10.06 - SLIDE 49IS 257 – Fall 2009 Lecture Outline Review –Relational Operations –Relational Algebra –Relational Calculus –Introduction to SQL Introduction to SQL (continued) Application Development in Access

50. 2009.10.06 - SLIDE 50IS 257 – Fall 2009 Database Applications Generally, end-users of database data probably do not want to learn SQL in order to access the information in the database Instead, they would prefer to use a familiar PC or Web interface that uses the graphical conventions and behaviors that they are familiar with Today we will look at PC –style client applications using systems like Access –Next time we will look at Web-based systems

51. 2009.10.06 - SLIDE 51IS 257 – Fall 2009 Query-by-Example QBE was developed in the 1970s as a simpler to use interface for IBM mainframe databases In QBE the user puts parts of what they want to get from the database into a form similar to what the output will look like The Query Design View in Access is an example of QBE

52. 2009.10.06 - SLIDE 52IS 257 – Fall 2009 Access Usability Hierarchy API VBA MACROS Functions/Expressions Objects – Tables, queries Forms, Reports From McFadden Chap. 10

53. 2009.10.06 - SLIDE 53IS 257 – Fall 2009 Examples Access OBJECT level –QBE querying Building Application interfaces –User wants “point and click” and forms to fill in, not a Query editing screen or wizard –How to build them Drag and drop as in Access Programming Languages 4 th Generation languages (more on these later)

54. 2009.10.06 - SLIDE 54IS 257 – Fall 2009 The MS JET Database Engine Database app Visual BasicAccessExcelWord Visual Basic for Applications (VBA) Host Languages for the Jet DBMS Data Access Objects (DAO) Includes DDL and DML Jet Database Engine (Jet DBMS) Jet Query Engine Internal ISAM Replication Engine Database Adapted from Roman, “Access Database Design and Programming”

55. 2009.10.06 - SLIDE 55IS 257 – Fall 2009 Using Access for Applications Forms Reports Macros VBA programming Application framework HTML Pages

56. 2009.10.06 - SLIDE 56IS 257 – Fall 2009 Assignment 3 Diveshop in MySQL –Look at instructions on the Assignments page –Or follow the phpMyAdmin instructions from Kevin Heard’s tutorial New set of questions using the MySQL version of the Diveshop database –Download and install your own copy of the database –Be sure to read each question carefully (make sure when it says “rent” that you are looking at the correct prices, etc.