更多的 SQL 和 MySQL

343 views

Published on

更多的 SQL 和 MySQL

http://www.ossez.com/forum.php?mod=viewthread&tid=26868&fromuid=426
(出处: OSSEZ)

Published in: Technology
  • Be the first to comment

  • Be the first to like this

更多的 SQL 和 MySQL

  1. 1. 2006.10.19 SLIDE 1IS 257 – Fall 2006 More on SQL (and MySQL) University of California, Berkeley School of Information IS 257: Database Management
  2. 2. 2006.10.19 SLIDE 2IS 257 – Fall 2006 Lecture Outline • Review – ColdFusion – PHP • More on ORACLE SQL and SQL-Plus • MySQL
  3. 3. 2006.10.19 SLIDE 3IS 257 – Fall 2006 Web Application Server Software • ColdFusion • PHP • ASP • All of the are server-side scripting languages that embed code in HTML pages
  4. 4. 2006.10.19 SLIDE 4IS 257 – Fall 2006 ColdFusion • Developing WWW sites typically involved a lot of programming to build dynamic sites – e.g. Pages generated as a result of catalog searches, etc. • ColdFusion was designed to permit the construction of dynamic web sites with only minor extensions to HTML through a DBMS interface
  5. 5. 2006.10.19 SLIDE 5IS 257 – Fall 2006 What ColdFusion is Good for • Putting up databases onto the Web • Handling dynamic databases (Frequent updates, etc) • Making databases searchable and updateable by users.
  6. 6. 2006.10.19 SLIDE 6IS 257 – Fall 2006 Templates • Assume we have a database named contents_of_my_shopping_cart.mdb -- single table called contents... • Create an HTML page (uses extension .cfm), before <HEAD>... • <CFQUERY NAME= ”cart" DATASOURCE=“contents_of_my_shopping_ca rt"> SELECT * FROM contents ; </CFQUERY>
  7. 7. 2006.10.19 SLIDE 7IS 257 – Fall 2006 Templates cont. • <HEAD> • <TITLE>Contents of My Shopping Cart</TITLE> • </HEAD> • <BODY> • <H1>Contents of My Shopping Cart</H1> • <CFOUTPUT QUERY= ”cart"> • <B>#Item#</B> <BR> • #Date_of_item# <BR> • $#Price# <P> • </CFOUTPUT> • </BODY> • </HTML>
  8. 8. 2006.10.19 SLIDE 8IS 257 – Fall 2006 Templates cont. Contents of My Shopping Cart Bouncy Ball with Psychedelic Markings 12 December 1998 $0.25 Shiny Blue Widget 14 December 1998 $2.53 Large Orange Widget 14 December 1998 $3.75
  9. 9. 2006.10.19 SLIDE 9IS 257 – Fall 2006 PHP • PHP is an Open Source Software project with many programmers working on the code. – Commonly paired with MySQL, another OSS project – Free – Both Windows and Unix support • Estimated that more than 250,000 web sites use PHP as an Apache Module.
  10. 10. 2006.10.19 SLIDE 10IS 257 – Fall 2006 PHP Syntax • Similar to ASP • Includes most programming structures (Loops, functions, Arrays, etc.) • Loads HTML form variables so that they are addressable by name <HTML><BODY> <?php $myvar = “Hello World”; echo $myvar ; ?> </BODY></HTML>
  11. 11. 2006.10.19 SLIDE 11IS 257 – Fall 2006 Combined with MySQL • DBMS interface appears as a set of functions: <HTML><BODY> <?php $db = mysql_connect(“localhost”, “root”); mysql_select_db(“mydb”,$db); $result = mysql_query(“SELECT * FROM employees”, $db); Printf(“First Name: %s <br>n”, mysql_result($result, 0 “first”); Printf(“Last Name: %s <br>n”, mysql_result($result, 0 “last”); ?></BODY></HTML>
  12. 12. 2006.10.19 SLIDE 12IS 257 – Fall 2006 SELECT • Syntax: – SELECT [DISTINCT] attr1, attr2,…, attr3 as label, function(xxx), calculation, attr5, attr6 FROM relname1 r1, relname2 r2,… rel3 r3 WHERE condition1 {AND | OR} condition2 ORDER BY attr1 [DESC], attr3 [DESC]
  13. 13. 2006.10.19 SLIDE 13IS 257 – Fall 2006 CREATE SYNONYM • CREATE SYNONYM newname FOR oldname; • CREATE SYNONYM BIOLIFE for ray.BIOLIFE;
  14. 14. 2006.10.19 SLIDE 14IS 257 – Fall 2006 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 ‘%wom_n%’ (Note different wild card) • IN (‘opt1’, ‘opt2’,…,’optn’)
  15. 15. 2006.10.19 SLIDE 15IS 257 – Fall 2006 Aggregate Functions • COUNT(dataitem) • AVG(numbercolumn) • SUM(numbercolumn) • MAX(numbercolumn) • MIN(numbercolumn) • STDDEV(numbercolumn) • VARIANCE(numbercolumn)
  16. 16. 2006.10.19 SLIDE 16IS 257 – Fall 2006 Numeric Functions • ABS(n) • ACOS(n) • ASIN(n) • ATAN(n) • ATAN2(n, m) • CEIL(n) • COS(n) • COSH(n) • ROUND(n) • SIGN(n) • SIN(n) • SINH(n) • SQRT(n) • TAN(n) • TANH(n) • TRUNC(n[, m]) • EXP(n) • EXP(n) • FLOOR(n) • LN(n) • LOG(m,n) • MOD(n) • POWER(m,n)
  17. 17. 2006.10.19 SLIDE 17IS 257 – Fall 2006 Character Functions returning character values • CHR(n) • CONCAT(char1,char2) • INITCAP(char) • LOWER(char) • LPAD(char, n,char2), RPAD(char, n,char2) • LTRIM(char, n, cset), RTRIM(char, n, cset) • REPLACE(char, srch, repl) • SOUNDEX(char) • SUBSTR(char, m, n) • SUBSTRB(char, m, n) • TRANSLATE(char, from, to) • UPPER(char)
  18. 18. 2006.10.19 SLIDE 18IS 257 – Fall 2006 Character Function returning numeric values • ASCII(char) • INSTR(char1, char2[,m, n]) • INSTRB(char1, char2[,m, n]) • LENGTH(char) • LENGTHB(char)
  19. 19. 2006.10.19 SLIDE 19IS 257 – Fall 2006 Date functions • ADD_MONTHS(dt, n) • LAST_DAY(d) • MONTHS_BETWEEN(d1, d2) • NEW_TIME(d, z1, z2) -- PST, AST, etc. • NEXT_DAY(d, dayname) • ROUND(d, fmt) -- century, year etc. • SYSDATE • TRUNC(d, fmt) -- century, year, etc.
  20. 20. 2006.10.19 SLIDE 20IS 257 – Fall 2006 Conversion Functions • CHARTOROWID(char) • CONVERT(char, dchar, schar) • HEXTORAW(char) • RAWTOHEX(raw) • ROWIDTOCHAR(rowid) • TO_CHAR (date, fmt) • TO_DATE(char, fmt) • TO_NUMBER(char,fmt ) • TO_MULTIBYTE(char) • TO_SINGLE_BYTE(ch ar)
  21. 21. 2006.10.19 SLIDE 21IS 257 – Fall 2006 Create Table • CREATE TABLE table-name (attr1 attr-type CONSTRAINT constr1 PRIMARY KEY, attr2 attr-type CONSTRAINT constr2 NOT NULL,…, attrM attr-type CONSTRAINT constr3 REFERENCES owner.tablename(attrname) ON DELETE CASCADE, attrN attr-type CONSTRAINT constrN CHECK (attrN = UPPER(attrN)), attrO attr-type DEFAULT default_value); • Adds a new table with the specified attributes (and types) to the database. – NOTE that the “CONSTRAINT and name parts are optional)
  22. 22. 2006.10.19 SLIDE 22IS 257 – Fall 2006 Create Table • CREATE TABLE table-name ( attr1 attr-type PRIMARY KEY, attr2 attr-type NOT NULL, …, attrM attr-type REFERENCES owner.tablename(attrname) ON DELETE CASCADE, attrN attr-type CHECK (attrN = UPPER(attrN) attrO attr-type DEFAULT default_value); – Without “CONSTRAINT” and name parts
  23. 23. 2006.10.19 SLIDE 23IS 257 – Fall 2006 Types • VARCHAR2(size) • NUMBER(p, s) • LONG -- long char data • DATE -- from 4712BC to 4714 AD • RAW(size) -- binary • LONG RAW -- large binary • ROWID -- row reference • CHAR(size) -- fixed length characters
  24. 24. 2006.10.19 SLIDE 24IS 257 – Fall 2006 Alter Table • ALTER TABLE table-name ADD attr1 attr- type; • ALTER TABLE table-name ADD attr1 CONSTRAINT xxx constrainvalue; • ALTER TABLE table-name MODIFY attr1 optiontochange; • ALTER TABLE table-name DROP COLUMN attr1; • Adds, drops or modifies a column in an existing database table. – Note: constrainvalue is any column constraint like ‘PRIMARY KEY’, REFERENCES, etc.
  25. 25. 2006.10.19 SLIDE 25IS 257 – Fall 2006 INSERT • INSERT INTO table-name (attr1, attr4, attr5,…, attrK) VALUES (“val1”, val4, val5,…, “valK”); • OR • INSERT INTO table-name SELECT col1, col2, col3 as newcol2, col4 FROM xx, yy WHERE where-clause; • Adds a new row(s) to a table.
  26. 26. 2006.10.19 SLIDE 26IS 257 – Fall 2006 DELETE • DELETE FROM table-name WHERE <where clause>; • Removes rows from a table.
  27. 27. 2006.10.19 SLIDE 27IS 257 – Fall 2006 UPDATE • UPDATE tablename SET attr1=newval, attr2 = newval2 WHERE <where clause>; • changes values in existing rows in a table (those that match the WHERE clause).
  28. 28. 2006.10.19 SLIDE 28IS 257 – Fall 2006 DROP Table • DROP TABLE tablename; • Removes a table from the database.
  29. 29. 2006.10.19 SLIDE 29IS 257 – Fall 2006 CREATE INDEX • CREATE [ UNIQUE ] INDEX indexname ON tablename (attr1 [ASC|DESC][, attr2 [ASC|DESC], ...]) • Adds an index on the specified attributes to a table
  30. 30. 2006.10.19 SLIDE 30IS 257 – Fall 2006 System Information In ORACLE • Find all of the tables for a user – SELECT * FROM ALL_CATALOG WHERE OWNER = ‘userid’; – SELECT * FROM USER_CATALOG; (or CAT) • Show the attributes and types of data for a particular table in SQLPlus – DESCRIBE tablename;
  31. 31. 2006.10.19 SLIDE 31IS 257 – Fall 2006 Running commands • Create file with SQL and SQLPlus commands in it. – Use a plain text editor and NOT a word processor (or save as text only) • Give the file the extension .sql • From inside SQLPlus type – START filename
  32. 32. 2006.10.19 SLIDE 32IS 257 – Fall 2006 Simple formatting in SQLPlus • SET PAGESIZE 500 • SET LINESIZE 79 • PROMPT stuff to put out to screen • TTITLE “title to put at top of results pages” • COLUMN col_name HEADING “New Name”
  33. 33. 2006.10.19 SLIDE 33IS 257 – Fall 2006 Outputting results as a file… • SPOOL filename • Commands – everything that you see is copied to the file until… • SPOOL STOP – File will be created with everything between the SPOOL commands
  34. 34. 2006.10.19 SLIDE 34IS 257 – Fall 2006 Lecture Outline • Review – ColdFusion – PHP • More on ORACLE SQL and SQL-Plus • MySQL
  35. 35. 2006.10.19 SLIDE 35IS 257 – Fall 2006 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
  36. 36. 2006.10.19 SLIDE 36IS 257 – Fall 2006 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
  37. 37. 2006.10.19 SLIDE 37IS 257 – Fall 2006 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
  38. 38. 2006.10.19 SLIDE 38IS 257 – Fall 2006 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)
  39. 39. 2006.10.19 SLIDE 39IS 257 – Fall 2006 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
  40. 40. 2006.10.19 SLIDE 40IS 257 – Fall 2006 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 Value CHAR(4) Storage VARCHAR(4) Storage "" " " 4 "" 1 "ab" "ab " 4 "ab" 3 "abcd" "abcd" 4 "abcd" 5 "abcdefg" "abcd" 4 "abcd" 5
  41. 41. 2006.10.19 SLIDE 41IS 257 – Fall 2006 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
  42. 42. 2006.10.19 SLIDE 42IS 257 – Fall 2006 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.
  43. 43. 2006.10.19 SLIDE 43IS 257 – Fall 2006 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
  44. 44. 2006.10.19 SLIDE 44IS 257 – Fall 2006 MySQL Demo • MySQL is on Dream, like ORACLE • 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 ray –p • Note that the version on Dream is not the latest – it is currently V. 3.23.58, latest is 5.1

×