Getting the total row count of a table without count()

The count(*) or count(pk) will be slow for large tables.

The alternate way to archive this as fast

Mssql-2000

SELECT rows
FROM sysindexes
WHERE object_name(id) = 'table_name'
AND indid =0


Mssql -2005 or more

SP_SPACEUSED table_name

Truncate all the table in a DB (MS-Sql 2000 & MS-Sql 2005)

Ms-Sql 2000

declare @SQL varchar(8000)

set @SQL = ''

select @SQL = @SQL + ' truncate table ' + name from sysobjects where type = 'U' and name <> 'dtproperties'

exec(@SQL)

Ms-Sql 2005

Exec sp_MsForEachTable 'TRUNCATE TABLE ?'

Create a row number or Serial no

In Ms-Sql 2005 and Oracle we have a built in function to generate row number or Serial no, But in

Ms-sql 2000 we have to generate serial no as follows!


CREATE TABLE Sample (
Number int
)


Insert Into sample

select 1 union
select 2 union
select 3 union
select 4 union
select 5 union
select 6 union
select 7 union
select 8 union
select 9 union
select 10


Select (select count(*) from Sample where number<=T.number) as Sno ,number
from Sample as T

Create Calendar in Ms Sql for any year

SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS ON
GO


/*

Exec CALENDAR 2009

*/


ALTER PROCEDURE CALENDAR (@YEAR INT) AS
DECLARE @INPUTDATE DATETIME
DECLARE @DATE DATETIME
DECLARE @LASTDATE DATETIME
DECLARE @MONTHDAYCOUNT INT
DECLARE @COUNT INT
DECLARE @DAY VARCHAR(10)
DECLARE @STARTWEEK INT
DECLARE @CURWEEK INT
DECLARE @STARTMONTH INT
SET @INPUTDATE='01/01/' + CAST(@YEAR AS CHAR(4))
PRINT @INPUTDATE
SET @STARTMONTH=1

WHILE @STARTMONTH<=12


BEGIN

SET @COUNT=1
SET @DATE = DATEADD(d, -(DATEPART(dd, @INPUTDATE) - 1), @INPUTDATE)

SELECT datename(month,@DATE) as Monthname
--print @DATE

SET @LASTDATE=DATEADD(DD,-1,DATEADD(MM,1,@DATE))
SET @MONTHDAYCOUNT=datediff(d, @date, dateadd(m, 1, @date))
SET @STARTWEEK=DATENAME(WEEK,@DATE)
DECLARE @CURRWEEK INT
DECLARE @CUR INT
CREATE TABLE #TEMP(
WEEK VARCHAR(10),
SUNDAY VARCHAR(10),
MONDAY VARCHAR(10),
TUESDAY VARCHAR(10),
WEDNESDAY VARCHAR(10),
THURSDAY VARCHAR(10),
FRIDAY VARCHAR(10),
SATURDAY VARCHAR(10))
DECLARE @wkcount int
DECLARE @weeksinmonth int
DECLARE @EXEC NVARCHAR(2000)
SET @WKCOUNT=1
SET @weeksinmonth=datediff(week, @date, @lastdate) + 1

WHILE @wkcount<= @weeksinmonth


begin
INSERT INTO #TEMP VALUES(@wkcount,'SUNDAY', 'MONDAY', 'TUESDAY', 'WEDNESDAY', 'THURSDAY', 'FRIDAY', 'SATURDAY')
SET @WKCOUNT=@WKCOUNT + 1
end


WHILE @COUNT<=@MONTHDAYCOUNT


BEGIN
SET @DAY=DATENAME(WEEKDAY,@DATE)
IF @STARTWEEK=DATENAME(WEEK,@DATE)
SET @CURRWEEK=1
ELSE
BEGIN
SET @CUR=DATENAME(WEEK,@DATE)
SET @CURRWEEK=(@CUR-@STARTWEEK)+1


END
--select * from #TEMP

SET @EXEC='UPDATE #TEMP SET ' + @DAY + ' =' + CAST(@COUNT AS CHAR(2)) + ' WHERE WEEK=' + CAST(@CURRWEEK AS CHAR(2))+ 'AND WEEK IS NOT NULL'
EXEC SP_EXECUTESQL @EXEC
SET @DATE=DATEADD(DD,1,@DATE)

SET @COUNT=@COUNT + 1
END


UPDATE #TEMP SET SUNDAY=' ' WHERE SUNDAY='SUNDAY'
UPDATE #TEMP SET MONDAY=' ' WHERE MONDAY='MONDAY'
UPDATE #TEMP SET TUESDAY=' ' WHERE TUESDAY='TUESDAY'
UPDATE #TEMP SET WEDNESDAY=' ' WHERE WEDNESDAY='WEDNESDAY'
UPDATE #TEMP SET THURSDAY=' ' WHERE THURSDAY='THURSDAY'
UPDATE #TEMP SET FRIDAY=' ' WHERE FRIDAY='FRIDAY'
UPDATE #TEMP SET SATURDAY=' ' WHERE SATURDAY='SATURDAY'

--select * from #TEMP
SELECT SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY FROM #TEMP
DROP TABLE #TEMP
SET @INPUTDATE=DATEADD(MM,1,@INPUTDATE)
SET @STARTMONTH=@STARTMONTH+1
END



GO
SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS ON
GO

Search a String in all columns of all tables in a database

CREATE PROC SearchAllTables
(
@SearchStr nvarchar(100)
)
AS
BEGIN



CREATE TABLE #Results (ColumnName nvarchar(370), ColumnValue nvarchar(3630))

SET NOCOUNT ON

DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110)
SET  @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')

WHILE @TableName IS NOT NULL
BEGIN
SET @ColumnName = ''
SET @TableName =
(
 SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
 FROM  INFORMATION_SCHEMA.TABLES
 WHERE   TABLE_TYPE = 'BASE TABLE'
  AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
  AND OBJECTPROPERTY(
    OBJECT_ID(
     QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
      ), 'IsMSShipped'
           ) = 0
)

WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
BEGIN
 SET @ColumnName =
 (
  SELECT MIN(QUOTENAME(COLUMN_NAME))
  FROM  INFORMATION_SCHEMA.COLUMNS
  WHERE   TABLE_SCHEMA = PARSENAME(@TableName, 2)
   AND TABLE_NAME = PARSENAME(@TableName, 1)
   AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar')
   AND QUOTENAME(COLUMN_NAME) > @ColumnName
 )

 IF @ColumnName IS NOT NULL
 BEGIN
  INSERT INTO #Results
  EXEC
  (
   'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630)
   FROM ' + @TableName + ' (NOLOCK) ' +
   ' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2
  )
 END
END
END

SELECT ColumnName, ColumnValue FROM #Results
END

Select the Nearest Integer value by passing Float

Consider the Sample table



Query:

Ms-Sql:

select top 1 number from Sample order by abs(number-3.7) ,number desc

My-Sql:

select number from Sample order by abs(number-3.7) ,number desc limit 1

E.F.Codd's 12 rules

Codd's 12 rules are a set of thirteen rules (numbered zero to twelve) proposed by Edgar F. Codd,
a pioneer of the relational model for databases, designed to define what is required from a database management system
in order for it to be considered relational, i.e., an RDBMS.

E.F. Codd released his Codd's rule in 1970 at the time of working in IBM's San Jose Research Laboratory


The rules

Rule 0: The system must qualify as relational, as a database, and as a management system.

For a system to qualify as a relational database management system (RDBMS), that system must use its relational facilities (exclusively) to manage the database.

Rule 1: The information rule:

All information in the database is to be represented in one and only one way, namely by values in column positions within rows of tables.

Rule 2: The guaranteed access rule:

All data must be accessible with no ambiguity. This rule is essentially a restatement of the fundamental requirement for primary keys. It says that every individual scalar value in the database must be logically addressable by specifying the name of the containing table, the name of the containing column and the primary key value of the containing row.

Rule 3: Systematic treatment of null values:

The DBMS must allow each field to remain null (or empty). Specifically, it must support a representation of "missing information and inapplicable information" that is systematic, distinct from all regular values (for example, "distinct from zero or any other number", in the case of numeric values), and independent of data type. It is also implied that such representations must be manipulated by the DBMS in a systematic way.

Rule 4: Active online catalog based on the relational model:

The system must support an online, inline, relational catalog that is accessible to authorized users by means of their regular query language. That is, users must be able to access the database's structure (catalog) using the same query language that they use to access the database's data.

Rule 5: The comprehensive data sublanguage rule:

The system must support at least one relational language that

1. Has a linear syntax
2. Can be used both interactively and within application programs,
3. Supports data definition operations (including view definitions), data manipulation operations (update as well as retrieval), security and integrity constraints, and transaction management operations (begin, commit, and rollback).

Rule 6: The view updating rule:

All views that are theoretically updatable must be updatable by the system.

Rule 7: High-level insert, update, and delete:

The system must support set-at-a-time insert, update, and delete operators. This means that data can be retrieved from a relational database in sets constructed of data from multiple rows and/or multiple tables. This rule states that insert, update, and delete operations should be supported for any retrievable set rather than just for a single row in a single table.

Rule 8: Physical data independence:

Changes to the physical level (how the data is stored, whether in arrays or linked lists etc.) must not require a change to an application based on the structure.

Rule 9: Logical data independence:

Changes to the logical level (tables, columns, rows, and so on) must not require a change to an application based on the structure. Logical data independence is more difficult to achieve than physical data independence.

Rule 10: Integrity independence:

Integrity constraints must be specified separately from application programs and stored in the catalog. It must be possible to change such constraints as and when appropriate without unnecessarily affecting existing applications.

Rule 11: Distribution independence:

The distribution of portions of the database to various locations should be invisible to users of the database. Existing applications should continue to operate successfully :

1. when a distributed version of the DBMS is first introduced; and
2. when existing distributed data are redistributed around the system.

Rule 12: The nonsubversion rule:

If the system provides a low-level (record-at-a-time) interface, then that interface cannot be used to subvert the system, for example, bypassing a relational security or integrity constraint.