Metadata in SQL Server

What is metadata? Usually this is used as a description of data.

"Depending on your viewpoint, metadata is used to add context and understanding about data that users are accessing, or it can be used to hide complexity from end users who are not required to know or understand the technical details of data. Metadata can also be used by systems to determine data types, to reveal the structure and relationships between data, or to determine if and when data last changed, and what changes were made to data. Metadata is also used by applications and systems to perform type checking, data validation, and formatting of data." ( TechNet )

Metadata is managed with the folllowing stored procedures:

Add an extended property	sp_addextendedproperty
Delete an extended property	sp_dropextendedproperty
Update an extended property	sp_updateextendedproperty
View an extended property	fn_listextendedproperty sys.extended_properties

Here is an example of extended property update:

USE AdventureWorks;
GO
EXEC sys.sp_updateextendedproperty
@name = N'MS_Description',
@value = N'New Description for the Address table',
@level0type = N'SCHEMA', @level0name = Person,
@level1type = N'TABLE', @level1name = Address;
GO

You can view the metadata with SELECT statement but you cannot modify it using UPDATE:

sp_configure 'allow updates',1
update sys.extended_properties set value='111' WHERE name='Purpose';

Result:
Ad hoc updates to system catalogs are not allowed.

We can not update neither system tables nor system views. This is regardless whether we've set "allow updates" or not. Use special procedures.

You can read more about metadata at http://msdn.microsoft.com/en-us/library/cc966384.aspx#ECAA

How to add 1 day to the date

MySQL : dateadd(dd, 1, getdate())
Oracle : SYSTIMESTAMP+NUMTODSINTERVAL(1,'day')
DB2 : CURRENT TIMESTAMP+1 DAY
PostgreSQL : LOCALTIMESTAMP+INTERVAL '1 day'

BCP and problems with Unicode

If you try loading the unicode file into mssql table that's what happens:

> bcp madhu1.dbo.testunicode in "D:\testunicode.txt" -S ABCSqlSrv -U sa -P sa -f "d:\fmt.txt"

Starting copy...
SQLState = HY000, NativeError = 0
Error = [Microsoft][SQL Native Client]Unexpected EOF encountered in BCP data-file

0 rows copied.
Network packet size (bytes): 4096
Clock Time (ms.) Total : 1

=================================

contents of testunicode.txt are :

मधुकर|pune|33
राहुल|pune|36

==========================

contents of format file fmt.txt are

8.0
3
1 SQLNCHAR 0 0 "|" 1 name SQL_Latin1_General_CP1_CI_AS
2 SQLNCHAR 0 0 "|" 2 address SQL_Latin1_General_CP1_CI_AS
3 SQLNCHAR 0 0 "\r\n" 3 age SQL_Latin1_General_CP1_CI_AS

================

However, this can be avoided by using -w option and removing -f option

Sphinx example for PHP

Here is a great example for Sphinx written in PHP : http://www.sphinxsearch.com/wiki/doku.php?id=php_example_script

Have fun.

Resetting forgotten root password

if you forgot the root password - here is the recipe to reset it:

1) kill mysqld
2) run

mysqld_safe –skip-grant-tables &

mysql -u root mysql

mysql> UPDATE user SET Password=PASSWORD(’newrootpassword’) WHERE User=’root’;
mysql> FLUSH PRIVILEGES;

3) kill the started MySQL server
4) restart it

Resetting forgotten root password

if you forgot the root password - here is the recipe to reset it:

1) kill mysqld
2) run

mysqld_safe –skip-grant-tables &

mysql -u root mysql

mysql> UPDATE user SET Password=PASSWORD(’newrootpassword’) WHERE User=’root’;
mysql> FLUSH PRIVILEGES;

3) kill the started MySQL server
4) restart it

Example of MSSQL quiet installation

It installs only MSSQL engine. Other possible features can be: SSMS, ADV_SSMS, BOL...

Setup.exe /QUIET
/INDICATEPROGRESS
/Action=Install
/FEATURES=SQLENGINE
/INSTANCENAME="EVAL33"
/SQLSYSADMINACCOUNTS="BUILTIN\Administrators"
/SECURITYMODE=SQL /TCPENABLED="1"
/NPENABLED="1"
/ADDCURRENTUSERASSQLADMIN="True"
/SQLSVCSTARTUPTYPE="Automatic"
/SQLSVCACCOUNT="NT AUTHORITY\LOCAL SERVICE"
/SAPWD="xxxxx"