Ôñüðïò áìößäñïìçò ãñáöÞò åöáñìïãÞ áíáðáñáãùãÞò óõíáëëáãþí

Áõôü ôï Üñèñï âÞìá ðñïò âÞìá ðåñéãñÜöåé ôïí ôñüðï õëïðïßçóçò áìößäñïìåò óõíáëëáãÝò áíáðáñáãùãÞò. Áõôü ôï Üñèñï ðåñéãñÜöåé åðßóçò ôá èÝìáôá ðïõ åìðëÝêïíôáé óôçí õëïðïßçóç áìößäñïìåò óõíáëëáãÝò áíáðáñáãùãÞò.

Bidirectional Transactional Replication

Bidirectional transactional replication, also known as two-way transactional replication, permits a server to be both a publisher and a subscriber to the same data. Because the servers that participate in the replication will replicate any changes to the other servers, any changes are not be propagated back to the originating server.

For example, if you have two servers (Server A and Server B), the servers are said to be in bidirectional transactional replication if both of the following conditions are true:

• The changes that are made to Table T1 at Server A are replicated to Table T1 at Server B.
• The changes that are made to Table T1 at Server B are replicated to Table T1 at Server A.

Therefore, if a change originates from Server A, the change is replicated to Server B, but Server B does not propagate the same change back to Server A. Replication uses a loopback detection mechanism that the distributor uses to determine whether to send the changes back to originating server.

Plan the Topology for Bidirectional Transactional Replication

For bidirectional transactional replication, one of the servers can act as central subscriber, and all the other servers subscribe to the central subscriber. Therefore, any changes that originate at a server are replicated to the central subscriber, and then the central subscriber, in turn, replicates the changes to all the other servers that participate in the replication. However, with the help of the loopback detection mechanism, the distributor stops the change from being propagated to the originating server.

For example, if three servers (Server A, Server B, and Server C) participate in bidirectional transactional replication and Server A is the central subscriber, the publishers and subscribers are maintained in the following ways:

• Server A publishes to Server B and Server C.
• Server A subscribes from Server B and Server C.
• Server B publishes to and subscribes from only Server A.
• Server C publishes to and subscribes from only Server A.

Therefore, any change that originates at Server B is replicated to Server A and Server C.

Conflicts in Bidirectional Transactional Replication

When you make changes on a server that is participating in replication, the changes are replicated to all other participating servers. During this replication, conflicts may occur and replication may fail. The following list describes the possible conflicts and the ways that you can avoid these conflicts:

• If you insert a record that has a key into a table on one of the servers and another record that has the same key already exists on the other servers that participate in the replication, the replication does not propagate the changes to the other servers.
  
  Suggested ActionTo avoid this problem, make sure that you use different keys on each server that participates in the replication. To do so, allocate a predetermined range of keys to each server that participates in the replication. You can also use a composite key on each server.
• When you update a record that has been deleted on another server, the UPDATE statement affects zero rows on the server where the record has been deleted, and the replication fails with an error.
  
  Suggested ActionTo avoid this problem, perform one of the following steps:
  • ÊáôÜñãçóç ôïõ@@ROWCOUNTcheck after the actual UPDATE statement in the update custom stored procedure.
    
    -Þ-
  • ×ñÞóç ôïõ-Skiperrorsparameter for the distribution agent to skip this error. For more information about skipping errors in transactional replication, visit the following Microsoft Web site:
    
    http://msdn2.microsoft.com/en-us/library/aa178842(SQL.80).aspx (http://msdn2.microsoft.com/en-us/library/aa178842(SQL.80).aspx)
    -Þ-
  • Look for a record before the UPDATE statement in the update stored procedure. If no record exists, bypass the UPDATE statement, and the record is deleted on all the subscribers.
• When you update a column in a record that is updated at the same time on another server, the data may be different on the two servers.
  
  Suggested ActionTo avoid this problem, determine if the data is being updated at the same time on other servers, and then take any necessary action. To do so, modify the update custom stored procedure and use XCALL syntax to call the update stored procedure. The XCALL syntax provides the values for all the columns before the update procedure is called and provides the updated values in the column. You can compare the current value of the column against the value before the update stored procedure is called. If you see different values, the column is being updated at the same time by different servers. You can customize the stored procedure to select which value persists. For more information about how to use XCALL, visit the following Microsoft Web site:
  
  http://msdn2.microsoft.com/en-us/library/Aa237133(SQL.80).aspx (http://msdn2.microsoft.com/en-us/library/Aa237133(SQL.80).aspx)
  ÓÇÌÅÉÙÓÇYou can specify the XCALL syntax to call the corresponding update stored procedure or delete stored procedure by usingsp_addarticleduring publication. You can also specify the XCALL syntax by using SQL Server Enterprise Manager. Ãéá íá ôï êÜíåôå áõôü, áêïëïõèÞóôå ôá åîÞò âÞìáôá:
  1. In SQL Server Enterprise Manager, locate the publication that you want.
  2. Right-click the publication, and then clickÉäéüôçôåò (Properties).
  3. ÊÜíôå êëéê óôçí êáñôÝëáArticlestab, locate the article, and then click the article properties button (...) next to the article.
  4. ÓôïTable Article PropertiesðáñÜèõñï äéáëüãïõ ðëáßóéï, êÜíôå êëéê óôïCommandsTAB.
  5. ÓôïReplace UPDATE commands with this stored procedure callðëáßóéï êåéìÝíïõ, ðëçêôñïëïãÞóôåXCALL, êáé óôç óõíÝ÷åéá êÜíôå êëéê óôï êïõìðßOk.
  6. ÓôïPublication PropertiesðáñÜèõñï äéáëüãïõ ðëáßóéï, êÜíôå êëéê óôï êïõìðßOk.
• When you update different columns in a record, simultaneous updates of different columns of a record may sometimes lead to conflicts.
  
  Suggested ActionTo avoid this problem, determine if the different columns in the same record are updated at the same time, and then take any necessary action. To do so, modify the update custom stored procedure, and then use the XCALL syntax to call the update stored procedure. Because the XCALL syntax provides the values before the update stored procedure is called, you can add one of the following options to the update stored procedure before the actual update is performed:
  • Compare the current values of all the columns against their values before the update stored procedure is called.
  • Add a column to represent the row version and to compare its current value with its value before the update stored procedure is called.
  Different values indicate that different columns are being updated at the same time. You can then decide whether to update the column.
• When you delete a row that is being updated by another server at the same time, the replication may fail.
  
  Suggested ActionTo determine if a row is updated and deleted at the same time, use the XCALL syntax in the delete stored procedure. Compare every column of the row that is being deleted against the values before the delete stored procedure is called. Different values indicate that these updates are being performed at the same time. You can either delete or retain the updated row.
  
  ÓÇÌÅÉÙÓÇEven if you do not delete the record on the subscriber, the record no longer exists on the server that originated the DELETE statement.
• When you delete a row that is being deleted at the same time on another server that is participating in the replication, the replication fails because the DELETE statement does not affect any rows on some of the subscribers.
  
  Suggested ActionTo avoid this problem, perform one of the following steps:
  • ÊáôÜñãçóç ôïõ@@ROWCOUNTcheck after the actual DELETE statement in the update custom stored procedure.
    
    -Þ-
  • ×ñÞóç ôïõ-Skiperrorsç ðáñÜìåôñïò ìå ôïí áíôéðñüóùðï ôçò äéáíïìÞò ãéá íá ðáñáâëÝøåôå áõôü ôï óöÜëìá. Ãéá ðåñéóóüôåñåò ðëçñïöïñßåò ó÷åôéêÜ ìå ôá óöÜëìáôá skipping óôçí áíáðáñáãùãÞ óõíáëëáãþí, åðéóêåöèåßôå ôçí áêüëïõèç ôïðïèåóßá ôçò Microsoft óôï Web:
    
    .aspx http://msdn2.Microsoft.com/en-us/library/aa178842 (SQL.80) (http://msdn2.microsoft.com/en-us/library/aa178842(SQL.80).aspx)

ÓÇÌÅÉÙÓÇÊÜèå áíÜðôõîçò ìðïñåß íá áðáéôåß ìéá äéáöïñåôéêÞ ðñïóÝããéóç ãéá íá åðéëýóåôå áõôÝò ôéò äéåíÝîåéò, áíÜëïãá ìå ôéò áðáéôÞóåéò ôçò åñãáóßáò. ÁõôÝò ïé äéåíÝîåéò åßíáé åõêïëüôåñï ãéá ôçí åðßëõóç üôáí åìðëÝêïíôáé ìüíï äýï äéáêïìéóôÝò. ¼ôáí åìðëÝêïíôáé ðåñéóóüôåñá áðü äýï äéáêïìéóôÝò, åíäÝ÷åôáé íá ìðïñåßôå íá ÷ñçóéìïðïéÞóåôå áðïèçêåõìÝíåò äéáäéêáóßåò ãéá íá ðñïóäéïñßóåôå ôï äéáêïìéóôÞ ðïõ ðñïÝñ÷ïíôáé ïé áëëáãÝò. ÅíçìåñùìÝíç Ýêäïóç ðïõ åßíáé áðïèçêåõìÝíç äéáäéêáóßá ðïõ ÷ñçóéìïðïéåßôáé ãéá íá åíçìåñþóåôå ôéò åããñáöÝò óôï äéáêïìéóôÞ C äåí ãíùñßæåé áí ç áëëáãÞ äçìéïõñãÞèçêå óôï äéáêïìéóôÞ A Þ ôï äéáêïìéóôÞ â. ÁíáðáñáãùãÞò óõã÷þíåõóçò, óå áíôßèåóç ìå ôéò óõíáëëáãÝò áíáðáñáãùãÞò äåí Ý÷åé ó÷åäéáóôåß ãéá ôçí åðßëõóç ôùí äéåíÝîåùí. ÁíÜðôõîç óõíáëëáãþí áíáðáñáãùãÞ ìüíï óå óåíÜñéá üðïõ áðïöåýãïíôáé äéåíÝîåéò áíôß íá åðéëõèåß.

Õëïðïßçóç áìößäñïìçò ãñáöÞò óõíáëëáãþí áíáðáñáãùãÞò

Ãéá íá õëïðïéÞóåôå ôéò áìößäñïìåò óõíáëëáãÝò áíáðáñáãùãÞò, ðñÝðåé íá éó÷ýåé üëåò ïé áêüëïõèåò óõíèÞêåò:

• Ôá äåäïìÝíá åßíáé óõã÷ñïíéóìÝíá ìåôáîý ôùí äéáêïìéóôþí áíáðáñáãùãÞò.
• Âñßóêïíôáé áðïèçêåõìÝíåò äéáäéêáóßåò ðïõ ÷ñçóéìïðïéïýíôáé áðü áíáðáñáãùãÞ óå üëåò ôéò âÜóåéò äåäïìÝíùí ðïõ óõììåôÝ÷ïõí.
• Ç óõíäñïìÞ Ý÷åé ïñéóôåß ìå ôç ÷ñÞóç ôïõ@ loopback_detection = 'true'ÐáñÜìåôñïò.
  
  ÓÇÌÅÉÙÓÇÇ åðéëïãÞÏñéóìüò @ loopback_detection = 'true'Äåí åßíáé äéáèÝóéìç áõôÞí ôç óôéãìÞ óôï ðåñéâÜëëïí åñãáóßáò ÷ñÞóôç. ÅðïìÝíùò, ðñÝðåé íá åããñáöåßôå, ÷ñçóéìïðïéþíôáò ôïsp_addsubscriptionáðïèçêåõìÝíç äéáäéêáóßá.

ÅÜí åêôåëåßôå ôç äçìéïõñãßá áíôéãñÜöùí áóöáëåßáò êáé åðáíáöïñÜò, íá èõìÜóôå üôé äéáöïñåôéêÝò ôïðïèåóßåò áðáéôïýí äéáöïñåôéêïýò ðåñéïñéóìïýò ðñùôåýïíôïò êëåéäéïý, ãéá íá âåâáéùèåßôå üôé äåí äçìéïõñãïýíôáé äéðëÝò ðñùôåýïíôá êëåéäéÜ. Èõìçèåßôå åðßóçò íá äçìéïõñãÞóåôå üëïõò ôïõò ðåñéïñéóìïýò ìå ôïí üñï NOT FOR ÁÍÁÐÁÑÁÃÙÃÇÓ.

Ìðïñåßôå íá ÷ñçóéìïðïéÞóåôå ôï ðáñÜäåéãìá ðïõ áêïëïõèåß, ãéá íá ñõèìßóåôå ôéò áìößäñïìåò óõíáëëáãÝò áíáðáñáãùãÞò óå Ýíáí õðïëïãéóôÞ ðïõ åêôåëåß ôïí SQL Server 2000.

ÓÇÌÅÉÙÓÇÏé ðñïôÜóåéò Transact-SQL ðáñáôßèåíôáé ãéá êÜèå Ýíá áðü ôá ðáñáêÜôù âÞìáôá. ÅêôåëÝóôå ôéò ðñïôÜóåéò Transact-SQL ãéá ôçí åêôÝëåóç ôçò åñãáóßáò ðïõ áíáöÝñåôáé óôï ðñïçãïýìåíï âÞìá.

1. Äçìéïõñãßá åíüò äéáíïìÝá, ïé åêäüôåò êáé óõíäñïìçôÝò óå Ýíáí õðïëïãéóôÞ ðïõ åêôåëåß ôïí SQL Server. Ãéá íá ôï êÜíåôå áõôü, áêïëïõèÞóôå ôá åîÞò âÞìáôá:
   1. ÄçìéïõñãÞóôå äýï âÜóåéò äåäïìÝíùí:

      use master
      go
      
      create database test1
      go
      
      create database test2
      go
      

   2. ÄçìéïõñãÞóôå ôïõò äýï ðßíáêåò ðïõ Ý÷ïõí ÝíáÔáõôüôçôá (Identity)ï ïñéóìüò óôÞëçò ìå ôçí åðéëïãÞ NOT FOR ÁÍÁÐÁÑÁÃÙÃÇÓ:

      use test1
      go
      
      create table two_way_test1 
      (
      	pkcol		INTEGER PRIMARY KEY NOT NULL,
      	intcol		INTEGER IDENTITY(1,1) NOT FOR REPLICATION,
       	charcol		CHAR(100),
      	timestampcol 	TIMESTAMP
      )
      
      use test2
      go
      
      create table two_way_test2 
      (
      	pkcol 		INTEGER PRIMARY KEY NOT NULL,
      	intcol 		INTEGER IDENTITY(1000000000,1) NOT FOR REPLICATION,
       	charcol 	CHAR(100),
       	timestampcol 	TIMESTAMP
      )
      go

   3. Åê÷ùñÞóôå Ýíá ðñïêáèïñéóìÝíï åýñïò ôéìþí óôç óôÞëç ðñùôåýïíôïò êëåéäéïý, Ýôóé þóôå ïé ôéìÝò óå äéáöïñåôéêïýò äéáêïìéóôÝò äåí âñßóêïíôáé óôçí ßäéá ðåñéï÷Þ. Ãéá ðáñÜäåéãìá, ìðïñåßôå íá åðéâÜëåôå 1-1000, ìå ôçí ðåñéï÷Þ êëåéäéïý ãéá ôïtwo_way_test1ðßíáêáò ìå ôïTest1âÜóç äåäïìÝíùí êáé óôç óõíÝ÷åéá åðéâïëÞ 1001-2000 ìå ôçí ðåñéï÷Þ êëåéäéïý ãéátwo_way_test2ðßíáêáò ìå ôïTest2Database. Ãéá íá ãßíåé áõôü, ÷ñçóéìïðïéÞóôå ôïí áêüëïõèï êþäéêá:

      	-- Constraint to enforce a range of values between 1 and 1000 in database test1 
      use test1
      go
      
      alter table 
      	two_way_test1 
      with nocheck 
      add constraint 
      	checkprimcol check NOT FOR REPLICATION 
      	(
      		pkcol BETWEEN 1 and 1000
      	) 
      go 
      
      
      use test2
      go
      
      	-- Constraint to enforce a range of values between 1001 and 2000 in the database test2 
      
      alter table 
      	two_way_test2
      with nocheck 
      add constraint 
      	checkprimcol check NOT FOR REPLICATION 
      	(
      		pkcol BETWEEN 1001 and 2000
      	) 
      go 
      
      

2. Åíåñãïðïßçóç ôïõ äéáêïìéóôÞ ìå ôï äéáíïìÝá êáé óôç óõíÝ÷åéá íá äçìéïõñãÞóåôå ìéá âÜóç äåäïìÝíùí ôçò äéáíïìÞò:

   use master
   go
   sp_adddistributor @distributor = '<distributor name>' 
   go
   use master
   go
   sp_adddistributiondb @database='distribution'
   go

3. Åíåñãïðïßçóç üëùí ôùí õðïëïãéóôþí åêôåëåß ôïí SQL Server ðïõ óõììåôÝ÷ïõí óôçí áíáðáñáãùãÞ ôïõ ùò åêäüôåò:

   use master
   go
   
   exec sp_adddistpublisher 
   	@publisher = '<Your Server Name>', 
   	@distribution_db ='distribution', 
   	@security_mode = 0, 
   	@login = 'sa', 
   	@password = 'sa',
   	@working_directory ='<Location of Directory>'

4. Åíåñãïðïßçóç üëùí ôùí åíôïðéóìÝíùí âÜóåùí äåäïìÝíùí ãéá ôçí áíáðáñáãùãÞ:

   use master
   go
   
   exec sp_replicationdboption N'test1', N'publish', true
   go
   
   exec sp_replicationdboption N'test2', N'publish', true
   go
   

5. Äçìéïõñãßá ðñïóáñìïóìÝíçò áðïèçêåõìÝíåò äéáäéêáóßåò ãéá INSERT, UPDATE, êáé DELETE ëåéôïõñãßåò óå üëåò ôéò âÜóåéò äåäïìÝíùí ãéá íá åöáñìüóåôå ôéò áëëáãÝò ðïõ Ýãéíáí êáôÜ ôç äéÜñêåéá ôçò áíáðáñáãùãÞò.
   
   ÓÇÌÅÉÙÓÇÓõíÞèùò, üôáí åéóáãÜãåôå ìéá ôéìÞ óå ìéá óôÞëç ÉDENTITY, ôçí åðéëïãÞ IDENTITY_INSERT ãéá ôïí ðßíáêá ðñÝðåé íá åßíáé ON. ÁõôÞ ç åñãáóßá åðéôõã÷Üíåôáé ìå ôçí åðéëïãÞ NOT FOR ÁÍÁÐÁÑÁÃÙÃÇÓ ãéá åéóåñ÷üìåíç áíáðáñáãùãÞ ðáñÜãïíôåò.
   
   Äåí ìðïñåßôå íá åíçìåñþóåôå ôéò ôéìÝò óôç óôÞëç IDENTITY. ÅðïìÝíùò, üôáí åíçìåñþíåôå ôéò ôéìÝò êáôÜ ôç äéÜñêåéá ôçò áíáðáñáãùãÞò, ðñÝðåé íá êáôáñãÞóåôå ôéò ðáëéÝò ôéìÝò êáé íá åéóáãÜãåôå ôéò íÝåò ôéìÝò. Ãéá íá äçìéïõñãÞóåôå ôï ðñïóáñìïóìÝíï áðïèçêåõìÝíåò äéáäéêáóßåò, áêïëïõèÞóôå ôá åîÞò âÞìáôá:
   1. Äçìéïõñãßá ðñïóáñìïóìÝíçò áðïèçêåõìÝíùí äéáäéêáóéþí óå ôïTest1Database:

      use test1
      go
      
      -- INSERT Stored Procedure
      
      create procedure sp_ins_two_way_test1	
      	@pkcol int, 
      	@intcol int, 
      	@charcol char(100), 
      	@timestampcol timestamp,
      	@rowidcol uniqueidentifier
      as
      	insert into two_way_test1 
      	(
      		pkcol,
      		intcol,
      		charcol
      	) 
      	values
      	(
      		@pkcol, 
      		@intcol, 
      		@charcol
      	)
      go
      
      --UPDATE Stored Procedure
      
      create procedure sp_upd_two_way_test1	
      	@pkcol int, 
          	@intcol int, 
          	@charcol char(100), 
          	@timestampcol timestamp,
      	@rowidcol uniqueidentifier,
          	@old_pkcol int
      as
      	declare @x int
      	declare @y int
      	declare @z char(100)
       
      	select 
      		@x=pkcol, 
      		@y=intcol, 
      		@z=charcol 
      	from 
      		two_way_test1 
      	where 
      		pkcol = @pkcol
      
      
      
      	delete 
      		two_way_test1 
      	where 
      		pkcol=@pkcol
      
      
      
      	insert into two_way_test1 
      	(
      		pkcol, 
      		intcol, 
      		charcol
      	) 
      	values
      	(
      		case isnull(@pkcol,0) when 0 then @x else @pkcol end,
      		case isnull(@intcol,0) when 0 then @y else @intcol end,
      		case isnull(@charcol,'N') when 'N' then @z else @charcol end
      	)
      go
      
      --  DELETE Stored Procedure
      
      create procedure sp_del_two_way_test1 
      	@old_pkcol int
      as
      	delete 
      		two_way_test1 
      	where 
      		pkcol = @old_pkcol
      go
      
      

   2. Äçìéïõñãßá ðñïóáñìïóìÝíçò áðïèçêåõìÝíùí äéáäéêáóéþí óå ôïTest2Database:

      use test2
      go
      
      -- INSERT Stored Procedure
      
      create procedure sp_ins_two_way_test2	
      	@pkcol int, 
      	@intcol int, 
      	@charcol char(100), 
      	@timestampcol timestamp,
      	@rowidcol uniqueidentifier
      as
      	insert into two_way_test2 
      	(
      		pkcol,
      		intcol,
      		charcol
      	) 
      	values
      	(
      		@pkcol, 
      		@intcol, 
      		@charcol
      	)
      go
      
      --UPDATE Stored Procedure
      
      create procedure sp_upd_two_way_test2	
      	@pkcol int, 
          	@intcol int, 
          	@charcol char(100), 
          	@timestampcol timestamp,
      	@rowidcol uniqueidentifier,
          	@old_pkcol int
      as
      	declare @x int
      	declare @y int
      	declare @z char(100)
       
      	select 
      		@x=pkcol, 
      		@y=intcol, 
      		@z=charcol 
      	from 
      		two_way_test2 
      	where 
      		pkcol = @pkcol
      
      
      
      	delete 
      		two_way_test2 
      	where 
      		pkcol=@pkcol
      
      
      
      	insert into two_way_test2 
      	(
      		pkcol, 
      		intcol, 
      		charcol
      	) 
      	values
      	(
      		case isnull(@pkcol,0) when 0 then @x else @pkcol end,
      		case isnull(@intcol,0) when 0 then @y else @intcol end,
      		case isnull(@charcol,'N') when 'N' then @z else @charcol end
      	)
      go
      
      
      --  DELETE Stored Procedure
      
      create procedure sp_del_two_way_test2 
      	@old_pkcol int
      as
      	delete 
      		two_way_test2 
      	where 
      		pkcol = @old_pkcol
      go
      

6. ÄçìéïõñãÞóôå ìéá äçìïóßåõóç óõíáëëáãþí êáé ðñïóèÝóôå óôç äçìïóßåõóç êáé óôéò äýï Üñèñá ôïõTest1êáé ôïTest2âÜóåéò äåäïìÝíùí:

   --In the database test1.
   
   use test1
   go
   
   --  Adding the transactional publication.
   exec sp_addpublication 
   	@publication = N'two_way_pub_test1', 
   	@restricted = N'false',
   	@sync_method = N'native', 
   	@repl_freq = N'continuous',
   	@description = N'Transactional publication of database test1.',
   	@status = N'active', 
   	@allow_push = N'true', 
   	@allow_pull = N'true',
   	@allow_anonymous = N'false', 
   	@enabled_for_internet = N'false',
   	@independent_agent = N'false', 
   	@immediate_sync = N'false',
   	@allow_sync_tran = N'true', 
   	@autogen_sync_procs = N'true',
   	@retention = 72
   go
   
   exec sp_addpublication_snapshot 
   	@publication = N'two_way_pub_test1',
   	@frequency_type = 4,
   	@frequency_interval = 1, 
   	@frequency_relative_interval = 0,
   	@frequency_recurrence_factor = 1, 
   	@frequency_subday = 1,
   	@frequency_subday_interval = 0, 
   	@active_start_date = 0,
   	@active_end_date = 0, 
   	@active_start_time_of_day = 233000,
   	@active_end_time_of_day = 0
   go
   
   --  Adding the transactional articles.
   
   exec sp_addarticle 
   	@publication = N'two_way_pub_test1', 
   	@article = N'two_way_test1',
   	@source_owner = N'dbo', 
   	@source_object = N'two_way_test1',
   	@destination_table = N'two_way_test1', 
   	@type = N'logbased',
   	@creation_script = null, 
   	@description = null, 
   	@pre_creation_cmd = N'drop',
           @schema_option = 0x00000000000000F1, 
   	@status = 16,
   	@vertical_partition = N'false', 
   	@ins_cmd = N'CALL sp_ins_two_way_test2',
   	@del_cmd = N'CALL sp_del_two_way_test2',
   	@upd_cmd = N'CALL sp_upd_two_way_test2', 
   	@filter = null,
   	@sync_object = null
   go
   
   --  In the database test2
   use test2
   go
   
   --  Adding the transactional publication.
   
   exec sp_addpublication 
   	@publication = N'two_way_pub_test2', 
   	@restricted = N'false',
   	@sync_method = N'native', 
   	@repl_freq = N'continuous',
   	@description = N'Transactional publication of database test2',
   	@status = N'active', 
   	@allow_push = N'true', 
   	@allow_pull = N'true',
   	@allow_anonymous = N'false', 
   	@enabled_for_internet = N'false',
   	@independent_agent = N'false', 
   	@immediate_sync = N'false',
   	@allow_sync_tran = N'true', 
   	@autogen_sync_procs = N'true',
   	@retention = 72
   go
   
   exec sp_addpublication_snapshot 
   	@publication = N'two_way_pub_test2',
   	@frequency_type = 4,
   	@frequency_interval = 1, 
   	@frequency_relative_interval = 0,
   	@frequency_recurrence_factor = 1, 
   	@frequency_subday = 1,
   	@frequency_subday_interval = 0, 
   	@active_start_date = 0,
   	@active_end_date = 0, 
   	@active_start_time_of_day = 233000,
   	@active_end_time_of_day = 0
   go
   
   --  Adding the transactional articles.
   exec sp_addarticle 
   	@publication = N'two_way_pub_test2', 
   	@article = N'two_way_test2',
   	@source_owner = N'dbo', 
   	@source_object = N'two_way_test2',
   	@destination_table = N'two_way_test2', 
   	@type = N'logbased',
   	@creation_script = null, 
   	@description = null, 
   	@pre_creation_cmd = N'drop',
   	@schema_option = 0x00000000000000F1, 
   	@status = 16,
   	@vertical_partition = N'false', 
   	@ins_cmd = N'CALL sp_ins_two_way_test1',
   	@del_cmd = N'CALL sp_del_two_way_test1',
   	@upd_cmd = N'CALL sp_upd_two_way_test1', 
   	@filter = null,
   	@sync_object = null
   go
   

7. Åíåñãïðïßçóç ùò óõíäñïìçôÝò üëïõò ôïõò äéáêïìéóôÝò ðïõ óõììåôÝ÷ïõí óôçí áíáðáñáãùãÞ:

   exec sp_addsubscriber 
   	@subscriber = '<Your Server Name>', 
   	@login = '<login name>', 
   	@password = '<password>'
   go
   
   

8. Ðñïóäéïñéóìüò ìßá áðü ôéò âÜóåéò äåäïìÝíùí ùò êåíôñéêÞ óõíäñïìçôÞ. Create transactional subscriptions in all the databases that participate in the replication so that all the databases subscribe to the central subscriber and the central subscriber subscribes to all the other databases.
   
   For example, in this scenario, theTest1database is the central subscriber. Create transactional subscriptions in thetest2database that subscribe to the publication atTest1and in theTest1database that subscribe to the publication attest2.
   
   ÓÇÌÅÉÙÓÇCreate all the subscriptions with the LOOPBACK_DETECTION option enabled.
   
   To do so, use the following code:

   --Adding the transactional subscription in test1.
   
   use test1
   go
   exec sp_addsubscription 
   	@publication = N'two_way_pub_test1', 
   	@article = N'all', 
   	@subscriber = '<Your Server Name>', 
   	@destination_db = N'test2', 
   	@sync_type = N'none', 
   	@status = N'active', 
   	@update_mode = N'sync tran', 
   	@loopback_detection = 'true'
   go
   
   -- Adding the transactional subscription in test2.
   
   use test2
   go
   exec sp_addsubscription 
   	@publication = N'two_way_pub_test2', 
   	@article = N'all', 
   	@subscriber = '<Your Server Name>', 
   	@destination_db = N'test1', 
   	@sync_type = N'none', 
   	@status = N'active', 
   	@update_mode = N'sync tran', 
   	@loopback_detection = 'true'
   go
   

ÓÇÌÅÉÙÓÇYou can also create custom stored procedures for all publications by using thesp_scriptpublicationcustomprocsóýóôçìá áðïèçêåõìÝíçò äéáäéêáóßáò. Ãéá ðåñéóóüôåñåò ðëçñïöïñßåò ó÷åôéêÜ ìå ôïsp_scriptpublicationcustomprocssystem stored procedure, see the "sp_scriptpublicationcustomprocs" topic in SQL Server 2000 Updated Books Online.

ÓÇÌÅÉÙÓÇSQL Query Analyzer returns only 256 characters per column. You can change this option to the maximum allowed value.

Ãéá ðåñéóóüôåñåò ðëçñïöïñßåò, êÜíôå êëéê óôïõò áñéèìïýò ôùí Üñèñùí ðáñáêÜôù ãéá íá ðñïâÜëåôå ôá Üñèñá ôçò ÃíùóéáêÞò ÂÜóçò ôçò Microsoft (Knowledge Base):For additional information about implementing bidirectional transactional replication in SQL Server 7.0, click the following article numbers to view the articles in the Microsoft Knowledge Base: