Author: Jugal Shah

  • Ranking Function – Row_Number

    Ranking functions are functions that allow you to sequentially number your result set.

    Syntax

    ROW_NUMBER ( ) OVER ([ ] )

    partition_by_clause is a column or set of columns used to determine the grouping in which the ROW_NUMBER function applies sequential numbering.

    order_by_clause is a column or set of columns used to order the result set within the grouping.

    Examples

    CREATE TABLE Emp(
    EmpName VARCHAR(9),
    Age INT,
    MaritalStatus char(1))

    INSERT INTO Emp VALUES ('Abhinav',40,'S')
    INSERT INTO Emp VALUES ('Dhvani',20,'M')
    INSERT INTO Emp VALUES ('Nehal',20,'M')
    INSERT INTO Emp VALUES ('Sunil',95,'M')
    INSERT INTO Emp VALUES ('Bill',11,'S')
    INSERT INTO Emp VALUES ('Ram',100,'S')
    INSERT INTO Emp VALUES ('Nirmal',50,'S')


    Sample - 1
    SELECT ROW_NUMBER() OVER (ORDER BY Age) AS [Row Number by Age],
    EmpName,
    Age
    FROM Emp
    Sample - 2
    SELECT ROW_NUMBER() OVER (ORDER BY Age desc) AS [Row Number by Age],
    EmpName,
    Age
    FROM Emp

    Row Number by Age EmpName Age
    ——————– ——— ———–
    1 Bill 11
    2 Dhvani 20
    3 Nehal 20
    4 Abhinav 40
    5 Nirmal 50
    6 Sunil 95
    7 Ram 100

    (7 row(s) affected)

    Sample - 3
    SELECT ROW_NUMBER() OVER (PARTITION BY MaritalStatus ORDER BY Age) AS [Partition by MaritalStatus],
    EmpName,
    Age,
    MaritalStatus
    FROM Emp

    Partition by MaritalStatus EmpName Age MaritalStatus
    -------------------------- --------- ----------- -------------
    1 Dhvani 20 M
    2 Nehal 20 M
    3 Sunil 95 M
    1 Bill 11 S
    2 Abhinav 40 S
    3 Nirmal 50 S
    4 Ram 100 S

    (7 row(s) affected)

  • xp_enumgroups Extended stored procedure

    xp_enumgroups Extended stored procedure returns the list of Windows NT groups and their description. To get the list of the Windows NT groups, run:

    Sample
    EXEC master..xp_enumgroups

  • How to read error log using T-SQL?

    xp_enumerrorlogs
    This extended stored procedure returns the list of all error logs with their last change date and size. To get the list of error logs, run:

    XP_ReadErrorLog: You can execute below query to read the error log. You can read the archive file by giving the number as per the output of xp_enumerrorlogs command.  If you will not specify any file number it will open the current error log file.

    EXEC sys.xp_readerrorlog @p1

    @p1 = file number you want to read.

  • How to check SQL Server Authentication Mode using T-SQL and SSMS?

    Dear Readers,

    Check Out my new article on MSSQLTips.com
    Visit MSQLTips
    Thanks,
    Jugal Shah

  • Database Level Fixed Roles

    DB Levek Fixed Roles Rights and Description
    db_accessadmin Members can manage Windows groups and SQL Server logins.
    db_backupoperator Issue DBCC, CHECKPOINT, and BACKUP statements.
    db_datareader Select all data from any user table in the database
    db_datawriter Modify any data in any user table in the database
    db_ddladmin Issue all Data Definition Language (DDL) statements
    db_denydatareader Cannot select any data from any user table in the database
    db_denydatawriter Cannot modify any data in any user table in the database
    db_owner Has full permissions to the database
    db_securityadmin Members can modify role membership and manage permissions.