The tablediff
utility enables you to compare the contents of two tables. It was
originally developed for replication scenarios to help troubleshoot
nonconvergence, but it is also very useful in other scenarios. When
data in two tables should be the same or similar, this tool can help
determine whether they are the same, and if they are different, it can
identify what data in the tables is different.
The syntax for tablediff is as follows:
tablediff
[ -? ] |
{
-sourceserver source_server_name[\instance_name]
-sourcedatabase source_database
-sourcetable source_table_name
[ -sourceschema source_schema_name ]
[ -sourcepassword source_password ]
[ -sourceuser source_login ]
[ -sourcelocked ]
-destinationserver destination_server_name[\instance_name]
-destinationdatabase subscription_database
-destinationtable destination_table
[ -destinationschema destination_schema_name ]
[ -destinationpassword destination_password ]
[ -destinationuser destination_login ]
[ -destinationlocked ]
[ -b large_object_bytes ]
[ -bf number_of_statements ]
[ -c ]
[ -dt ]
[ -et table_name ]
[ -f [ file_name ] ]
[ -o output_file_name ]
[ -q ]
[ -rc number_of_retries ]
[ -ri retry_interval ]
[ -strict ]
[ -t connection_timeouts ]
}
The tablediff
syntax requires source and destination connection information to
perform a comparison. This information includes the servers, databases,
and tables that will be compared. Connection information must be
provided for SQL Server authentication but can be left out if Windows
authentication can be used. The source and destination parameters can
be for two different servers or the same server, and the tablediff utility can be run on a machine that is neither the source nor the destination.
To illustrate the usefulness of this tool, let’s look at a sample comparison in the AdventureWorks2008R2
database. The simplest way to create some data for comparison is to
select the contents of one table into another and then update some of
the rows in one of the tables. The following SELECT statement makes a copy of the AddressType table in the AdventureWorks2008R2 database to the AddressTypeCopy table:
select *
into Person.AddressTypeCopy
from Person.AddressType
In addition, the following statement updates two rows in the AddressTypeCopy table so that you can use the tablediff utility to identify the changes:
UPDATE Person.AddressTypeCopy
SET Name = 'Billing New'
WHERE AddressTypeId = 1
UPDATE Person.AddressTypeCopy
SET Name = 'Shipping New',
ModifiedDate = '20090918'
WHERE AddressTypeId = 5
The tablediff utility can be executed with the following parameters to identify the differences in the AddressType and AddressTypeCopy tables:
tablediff -sourceserver "(local)" -sourcedatabase "AdventureWorks2008R2"
-sourceschema "Person"-sourcetable "AddressType"
-destinationserver "(local)" -destinationdatabase "AdventureWorks2008R2"
-destinationschema "Person" -destinationtable "AddressTypeCopy"
-f c:\TableDiff_Output.txt
The destination and source
parameters are the same as in the previous example, except for the
table parameters, which have the source AddressType and the destination AddressTypeCopy. The execution of the utility with these parameters results in the following output to the command prompt window:
User-specified agent parameter values:
-sourceserver (local)
-sourcedatabase AdventureWorks2008R2
-sourceschema Person
-sourcetable AddressType
-destinationserver (local)
-destinationdatabase AdventureWorks2008R2
-destinationschema Person
-destinationtable AddressTypeCopy
-f c:\TableDiff_Output
Table [AdventureWorks2008R2].[Person].[AddressType] on (local)
and Table [AdventureWorks2008R2].[Person].[AddressTypeCopy] on (local)
have 2 differences.
Fix SQL written to c:\TableDiff_Output.sql.
Err AddressTypeID Col
Mismatch 1 Name
Mismatch 5 ModifiedDate Name
The requested operation took 0.296875 seconds.
The output first displays a
summary of the parameters used and then shows the comparison results.
In this example, it found the two differences that are due to updates
performed on AddressTypeCopy. In addition, the –f parameter used in the example caused the tablediff
utility to output a SQL file that can be used to fix the differences in
the destination table. The output file from this example looks as
follows:
— Host: (local)
— Database: [AdventureWorks2008R2]
— Table: [Person].[AddressTypeCopy]
SET IDENTITY_INSERT [Person].[AddressTypeCopy] ON
UPDATE [Person].[AddressTypeCopy]
SET [Name]='Billing'
WHERE [AddressTypeID] = 1
UPDATE [Person].[AddressTypeCopy]
SET [ModifiedDate]='2002-06-01 00:00:00.000',
[Name]='Shipping' WHERE [AddressTypeID] = 5
SET IDENTITY_INSERT [Person].[AddressTypeCopy] OFF
Note
The tablediff utility requires the source table to have at least one primary key, identity, or ROWGUID column. This gives the utility a key that it can use to try to match a corresponding row in the destination table. If the –strict option is used, the destination table must also have a primary key, identity, or ROWGUID column.
Keep in mind that several different types of comparisons can be done with the tablediff utility. The –q option causes a quick comparison that compares only record counts and looks for differences in the schema. The –strict
option forces the schemas of each table to be the same when the
comparison is run. If this option is not used, the utility allows some
columns to be of different data types, as long as they meet the mapping
requirements for the data type (for example, INT can be compared to BIGINT).
The tablediff
utility can be used for many different types of comparisons. How you
use this tool depends on several factors, including the amount and type
of data you are comparing.
