To Know the Backup set used to restore a SQL Server database

SELECT a.restore_date ,

a.destination_database_name ,

a.user_name ,

b.server_name ,

c.physical_device_name

FROM restorehistory a

INNER JOIN Backupset b ON a.backup_set_id = b.backup_set_id

INNER JOIN backupmediafamily c ON b.media_set_id = c.media_set_id

WHERE destination_database_name = 'databasename'

Copy one Column data from one table to other table in SQL Server

INSERT INTO NewTable ColumnName      
SELECT ColumnName FROM OldTable

Avoid/Remove displaying '1900-01-01 00:00:00.000' if date column is null

UPDATE YOURTABLE
SET ThatColumn = NULL
WHERE ThatColumn = '1900-01-01 00:00:00.000'

List all Tables in a Database

SELECT * FROM sysobjects WHERE xtype='U'

Find Log Size and Log Space Used on all databases

dbcc sqlperf(logspace)

Script: Extract data from all tables in a database to individual text files.

DECLARE @tablename  VARCHAR(256) 
DECLARE @cmd   VARCHAR(4000)
DECLARE @TABLE_NAME  VARCHAR(50)
DECLARE @DBname  VARCHAR(100)
DECLARE @TABLESCHEMA VARCHAR(100)
DECLARE @PathName VARCHAR(50)


DECLARE db_cursor CURSOR FOR
SELECT
  TABLE_DB     AS DBname,
  TABLE_SCHEMA AS TABLESCHEMA,
  TABLE_NAME   AS TABLENAME
FROM TABLE_NAMES_VIEW
OPEN db_cursor  
FETCH NEXT FROM db_cursor
 INTO @DBname,
      @TABLESCHEMA,
      @TABLENAME
WHILE @@FETCH_STATUS = 0  
BEGIN 
    SET @PathName = @DBname + '.' + @TABLESCHEMA + '.' + @TABLENAME
    SET @cmd = 'master.dbo.xp_cmdshell ''BCP '  + @PathName
      + ' out G:\output\' + @tablename + '.txt -t "|" -T -c'''
    PRINT @cmd
    EXEC (@cmd)
 FETCH NEXT FROM db_cursor 
 INTO @DBname,
      @TABLESCHEMA,
      @TABLENAME
END 

CLOSE db_cursor  
DEALLOCATE db_cursor

Change Column Data type in SQL Server

ALTER TABLE tablename
MODIFY COLUMNNAME Datatype.