User:Alhoori

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Contents

[edit] HI

[edit] Image Processing

[edit] HCI

[edit] AI

[edit] Data Mining

[edit] CSCW


  • Many authors consider that CSCW and groupware are synonyms
  • Different authors claim that while groupware refers to real computer-based systems, CSCW focuses on the study of tools and techniques of groupware as well as their psychological, social, and organizational effects
  • Cooperation and collaboration do not differ in terms of whether or not the task is distributed, but by virtue of the way in which it is divided; in cooperation the task is split (hierarchically) into independent subtasks; in collaboration cognitive processes may be (heterarchically) divided into intertwined layers. In cooperation, coordination is only required when assembling partial results, while collaboration is « ...a coordinated, synchronous activity that is the result of a continued attempt to construct and maintain a shared conception of a problem
  • Collaboration without limitation

[edit] Internet

[edit] 3D

[edit] Arch

[edit] DB

[edit] Ubiquitous Computing (UB)

[edit] Computer architecture

[edit] Operating system

[edit] IT

[edit] HPI


[edit] People

[edit] Quotes

[edit] Topics started


[edit] Firefox

[edit] General

[edit] RDF

  • RDF ( integrates a variety of applications using XML as an interchange syntax).

[edit] Used Tools

[edit] Wiki

  • Q & A in Wiki

[edit] XPI ( installer for xul components )

[edit] XUL

[edit] SE

[edit] To Learn

  • Agile
  • Graph Oriented Programming
  • Depandable Systems
  • Safty Critical Systems
  • ISO certis for software
  • systems engineering
  • AgletS

[edit] Java

[edit] World

[edit] Personal Development

[edit] Dates

  • Jan 15 , 2001 - Wikipedia, a free Wiki content encyclopedia, goes online.
  • Jan 2005 - WikiHow
  • July 10,2003 - Wikibooks was started
  • July 2003 - Wikitravel was started

[edit] Eduaction

[edit] Software

[edit] 2020

[edit] Wiki users

[edit] My Wikis


[edit] World

[edit] Colleges

[edit] Windows

[edit] VB

[edit] CS

[edit] Computer Organizations

[edit] Flash

[edit] MySQL

  • MySQL may not work correct in all cases.
  • variables , just use @var# , without any declaration.

[edit] Warnings

  show warnings;


[edit] File Path

  • windows , Windows pathnames are specified using / rather than \.
    1. forward slash , 'c:/path/subpath/'
    2. If you do use \, you must double them\\.

[edit] mysqlimport — A Data Import Program

  • The mysqlimport client provides a command-line interface to the LOAD DATA INFILE SQL statement. Most options to mysqlimport correspond directly to clauses of LOAD DATA INFILE syntax.
  shell> mysqlimport [options] db_name textfile1 [textfile2 ...]

For each text file named on the command line, mysqlimport strips any extension from the filename and uses the result to determine the name of the table into which to import the file's contents. For example, files named patient.txt, patient.text, and patient all would be imported into a table named patient.

(1)

 --fields-terminated-by=...,   --fields-enclosed-by=...,   --fields-optionally-enclosed-by=...,
 --fields-escaped-by=...

These options have the same meaning as the corresponding clauses for LOAD DATA INFILE. See

(2)

  --force, -f

Ignore errors. For example, if a table for a text file does not exist, continue processing any remaining files. Without --force, mysqlimport exits if a table does not exist.

(3)

  --host=host_name, -h host_name

Import data to the MySQL server on the given host. The default host is localhost.

(4) --local, -L

Read input files locally from the client host.

(5)

  --password[=password], -p[password]

The password to use when connecting to the server. If you use the short option form (-p), you cannot have a space between the option and the password. If you omit the password value following the --password or -p option on the command line, you are prompted for one.

(6)

  --user=user_name, -u user_name

The MySQL username to use when connecting to the server.

[edit] File -> table , LOAD DATA INFILE

  • The LOAD DATA INFILE statement reads rows from a text file into a table at a very high speed. The filename must be given as a literal string.
   LOAD DATA [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE 'file_name'
   [REPLACE | IGNORE]
   INTO TABLE tbl_name
   [FIELDS
       [TERMINATED BY 'string']
       [[OPTIONALLY] ENCLOSED BY 'char']
       [ESCAPED BY 'char']
   ]
   [LINES
       [STARTING BY 'string']
       [TERMINATED BY 'string']
   ]
   [IGNORE number LINES]
   [(col_name_or_user_var,...)]
   [SET col_name = expr,...)]
  • If you use LOW_PRIORITY, execution of the LOAD DATA statement is delayed until no other clients are reading from the table.

[edit] Example # 1

  load data local infile 'C:/Documents and Settings/hamed/Desktop/a.txt' into table t;


[edit] Example # 2

Store the data into the database directory folder ( ex C:\Program Files\MySQL\MySQL Server 5.0\data\databaseName)

  load data infile 'a.txt' into table t;
  • If LOCAL is specified, the file is read by the client program on the client host and sent to the server. The file can be given as a full pathname to specify its exact location. If given as a relative pathname, the name is interpreted relative to the directory in which the client program was started.


  • If LOCAL is not specified, the file must be located on the server host and is read directly by the server. The server uses the following rules to locate the file:
    1. If the filename is an absolute pathname, the server uses it as given.
    2. If the filename is a relative pathname with one or more leading components, the server searches for the file *#relative to the server's data directory.
  • Using LOCAL is a bit slower than letting the server access the files directly, because the contents of the file must be sent over the connection by the client to the server. On the other hand, you do not need the FILE privilege to load local files.
  • If you specify a FIELDS clause, each of its subclauses (TERMINATED BY, [OPTIONALLY] ENCLOSED BY, and ESCAPED BY) is also optional, except that you must specify at least one of them.

If you specify no FIELDS clause, the defaults are the same as if you had written this:

  FIELDS TERMINATED BY '\t' ENCLOSED BY ' ' ESCAPED BY '\\'
  • If you specify no LINES clause, the defaults are the same as if you had written this:
  LINES TERMINATED BY '\n' STARTING BY ' '
  • Warnings
    1. file with data that are not terminated by any special char and you don't use terminated by.
    2. Warning | 1262 | Row 1 was truncated; it contained more data than there were input columns ( ex 2 records ( 22 222 333 444 )


[edit] Example # 2

  load data local infile 'C:/Documents and Settings/hamed/Desktop/b.txt' 
  into table t 
  fields terminated by '\t' 
  lines terminated by '\r\n';

Example #3

  LOAD DATA local INFILE 'C:/Documents and Settings/hamed/Desktop/b.txt' 
  INTO TABLE t
  FIELDS TERMINATED BY ','  
  LINES STARTING BY 'xxx';

If the data file looks like this: xxx1,"abc" something xxx2,"def" 3,"ghi"

The resulting rows will be (1,"abc") and (2,"def"). The third row in the file is skipped because it does not contain the prefix.

  • The IGNORE number LINES option can be used to ignore lines at the start of the file. For example, you can use IGNORE 1 LINES to skip over an initial header line containing column names:

Example # 4

  LOAD DATA INFILE '/tmp/test.txt' INTO TABLE test IGNORE 1 LINES;


[edit] Example # 5

  LOAD DATA INFILE 'data.txt' INTO TABLE tbl_name
  FIELDS TERMINATED BY ',' ENCLOSED BY '"'
  LINES TERMINATED BY '\n';

By default, when no column list is provided at the end of the LOAD DATA INFILE statement, input lines are expected to contain a field for each table column. If you want to load only some of a table's columns, specify a column list:

  LOAD DATA INFILE 'persondata.txt' INTO TABLE persondata (col1,col2,...);

You must also specify a column list if the order of the fields in the input file differs from the order of the columns in the table. Otherwise, MySQL cannot tell how to match input fields with table columns.


With user variables, the SET clause enables you to perform transformations on their values before assigning the result to columns.

User variables in the SET clause can be used in several ways. The following example uses the first input column directly for the value of t1.column1, and assigns the second input column to a user variable that is subjected to a division operation before being used for the value of t1.column2:

 LOAD DATA INFILE 'file.txt'
 INTO TABLE t1
 (column1, @var1)
 SET column2 = @var1/100;

The SET clause can be used to supply values not derived from the input file. The following statement sets column3 to the current date and time:

 LOAD DATA INFILE 'file.txt'
 INTO TABLE t1
 (column1, column2)
 SET column3 = CURRENT_TIMESTAMP;


You can also discard an input value by assigning it to a user variable and not assigning the variable to a table column:

 LOAD DATA INFILE 'file.txt'
 INTO TABLE t1
 (column1, @dummy, column2, @dummy, column3);

[edit] Table -> File , SELECT ... INTO OUTFILE

To write data from a table to a file


[edit] where condition

This could be danger !!

Lets say a table contains a column with values ( 1,2,3)

  • DELETE from TABLE where column= 1 and 2;

Result = delete the record with column = 1


  • DELETE from TABLE where column=4 or 5;

Result = delete all the records in the tables , since the values 5 = true !


The correct query will be

  • DELETE from TABLE where column=4 or column=5;


[edit] Storage Engine

  • MyISAM = very fasy
  • InooDB = safe


[edit] Links


[edit] Tools

[edit] sql commands

  Use database_name;
  Show tables;
  Mysql –u username –p ;
  show columns from table_name;
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