SQL Server

1. String functions:len (expression) returns the number of characters (not bytes) of the given string expression, with no trailing spaces. DATALENGTH (char_expr) returns a string that contains the number of characters but does not contain the

1. View job History Select TOP [instance_id], [ job_id] , [step_id] , [step_name] , [sql_message_id] , [Sql_severity] , [message] , [run_status] , [run_date] , [run_time] , [run_duration] , [

After the SQL Server primary database is damaged, the SQL Server service fails to start, viewing the error log, and you see the following error message: ' master '. 2015-10-27 10:15:23.01 spid6s Error: 9003, severity: 20, State: 1. inch '

Definition and Usage:The CONVERT () function is a general function that converts a date to a new data type.The CONVERT () function can display date/time data in different formats.Grammar:CONVERT (data_type (length),

Today made a very annoying thing, accidentally put a 40 more g of the database log files deleted, and before the deletion I made a log in, dead or alive can not attach to the server has been prompted multiple logs cannot be automatically created,

In the database development process, we often encounter the situation to traverse the data table, a reference to traverse the table, our first impression may think of the use of cursors, although the use of cursors is intuitive, but it does not

SELECT [Spid] =session_id, Ecid,[Database] = db_name(sp.dbid),[User] =Nt_username,[Status] =er. STATUS,[Wait] =Wait_type,[individual Query] = SUBSTRING(QT.TEXT, Er.statement_start_offset/ 2, ( Case

Some of the operations of databases in SQL Server in Bulk_logged/simple mode take the form of minimizing log logging to reduce the amount of Tran log disk logs to improve overall performance.Here I'll briefly describe which operations will minimize

Introduction to the Logical query processing phase From : performs a cartesian product (Cartesian product) (cross join) on the first two tables in the FROM clause, generating a virtual table VT1 On : apply an on filter to VT1. Only those rows

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Metric Rapid Development Platform database supports SQL Server database, the way that we used to use the Oracle recursive query with the start with dept_id=1000 connect by prior dept_id=upper_id.For example, our organization has a lot of subordinate

A replication system has been set up to search the business, adding some special features to the business, and the read library pressure increases, resulting in replication delays. Optimizations are made in a variety of ways, one of which is to

/* General server dynamic management objects include: dm_db_*: Database and Database object dm_exec_*: Execute user code and associated connection dm_os_*: Memory, lock, and schedule dm_tran_*: Transactions and isolation dm_io_*: input/output */-for

1 --====================================2 --Create Database Trigger template3 --====================================4 Use [easyjobextest]5 GO6 7 --determine if a trigger exists, delete it8 IF EXISTS(9 Select Top 1T.name asTrigger_name,a.name

1.datetime,smalldatetime,date difference 1) datetimeDate and time data from January 1, 1753 to December 31, 9999, with an accuracy of 3% seconds (equal to 3.33 milliseconds or 0.00333 seconds). Adjust the values to. 000,. 003, or. 007 seconds

A stored procedure in Transact-SQL, very similar to a method in the Java language, can be called repeatedly. After the stored procedure executes once, the statement can be cached so that the statements in the cache are used directly at the next

Recommended books: MySQL must know, head first SQLViewA view is a virtual table, unlike a table that contains data, and the view contains only queries that retrieve data dynamically when they are used, and do not contain any data on their ownWhy use

SELECT * from Sys.servers;EXEC sp_helpserverexec sp_droplinkedsrvlogin dbvip,null--Deleting mappings (mapping to remote logins on linked servers) exec sp_dropserver DBVIP EX EC sp_addlinkedserver @server = ' DBVIP ',--the server alias being accessed

len (expression) returns the number of characters (not bytes) of the given string expression, with no trailing spaces. DATALENGTH (char_expr) returns a string that contains the number of characters but does not contain the following spacesLength

SELECTMig.index_group_handle, Mid.index_handle,CONVERT (Decimal (28,1),Migs.avg_total_user_cost * Migs.avg_user_impact * (Migs.user_seeks + Migs.user_scans)) as Improvement_measure,' CREATE index idx_ ' + object_name (object_id,database_id) + '