更多的 sql 和 mysql
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更多的 SQL 和 MySQL http://www.ossez.com/forum.php?mod=viewthread&tid=26868&fromuid=426 (出处: OSSEZ)TRANSCRIPT
2006.10.19 SLIDE 1
IS 257 – Fall 2006
More on SQL (and MySQL)
University of California, Berkeley
School of Information
IS 257: Database Management
2006.10.19 SLIDE 2
IS 257 – Fall 2006
Lecture Outline
• Review – ColdFusion
– PHP
• More on ORACLE SQL and SQL-Plus
• MySQL
2006.10.19 SLIDE 3
IS 257 – Fall 2006
Web Application Server Software
• ColdFusion
• PHP
• ASP
• All of the are server-side scripting
languages that embed code in HTML
pages
2006.10.19 SLIDE 4
IS 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
2006.10.19 SLIDE 5
IS 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.
2006.10.19 SLIDE 6
IS 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>
2006.10.19 SLIDE 7
IS 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>
2006.10.19 SLIDE 8
IS 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
2006.10.19 SLIDE 9
IS 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.
2006.10.19 SLIDE 10
IS 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>
2006.10.19 SLIDE 11
IS 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>
2006.10.19 SLIDE 12
IS 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]
2006.10.19 SLIDE 13
IS 257 – Fall 2006
CREATE SYNONYM
• CREATE SYNONYM newname FOR
oldname;
• CREATE SYNONYM BIOLIFE for
ray.BIOLIFE;
2006.10.19 SLIDE 14
IS 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’)
2006.10.19 SLIDE 15
IS 257 – Fall 2006
Aggregate Functions
• COUNT(dataitem)
• AVG(numbercolumn)
• SUM(numbercolumn)
• MAX(numbercolumn)
• MIN(numbercolumn)
• STDDEV(numbercolumn)
• VARIANCE(numbercolumn)
2006.10.19 SLIDE 16
IS 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)
2006.10.19 SLIDE 17
IS 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)
2006.10.19 SLIDE 18
IS 257 – Fall 2006
Character Function returning numeric values
• ASCII(char)
• INSTR(char1,
char2[,m, n])
• INSTRB(char1,
char2[,m, n])
• LENGTH(char)
• LENGTHB(char)
2006.10.19 SLIDE 19
IS 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.
2006.10.19 SLIDE 20
IS 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)
2006.10.19 SLIDE 21
IS 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)
2006.10.19 SLIDE 22
IS 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
2006.10.19 SLIDE 23
IS 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
2006.10.19 SLIDE 24
IS 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.
2006.10.19 SLIDE 25
IS 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.
2006.10.19 SLIDE 26
IS 257 – Fall 2006
DELETE
• DELETE FROM table-name WHERE <where clause>;
• Removes rows from a table.
2006.10.19 SLIDE 27
IS 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).
2006.10.19 SLIDE 28
IS 257 – Fall 2006
DROP Table
• DROP TABLE tablename;
• Removes a table from the database.
2006.10.19 SLIDE 29
IS 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
2006.10.19 SLIDE 30
IS 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;
2006.10.19 SLIDE 31
IS 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
2006.10.19 SLIDE 32
IS 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”
2006.10.19 SLIDE 33
IS 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
2006.10.19 SLIDE 34
IS 257 – Fall 2006
Lecture Outline
• Review – ColdFusion
– PHP
• More on ORACLE SQL and SQL-Plus
• MySQL
2006.10.19 SLIDE 35
IS 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
2006.10.19 SLIDE 36
IS 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
2006.10.19 SLIDE 37
IS 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
2006.10.19 SLIDE 38
IS 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)
2006.10.19 SLIDE 39
IS 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
2006.10.19 SLIDE 40
IS 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
2006.10.19 SLIDE 41
IS 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
2006.10.19 SLIDE 42
IS 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.
2006.10.19 SLIDE 43
IS 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
2006.10.19 SLIDE 44
IS 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