Comparison Query to Compare Two SQL Server Tables [duplicate] - sql

Question

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sql query to return differences between two tables
(14 answers)
Closed 6 years ago.
I would like to know how to compare two different database table records. What I mean is I will compare two database tables which may have different column names but same data. But one of them may have more records than the other one so I want to see what the difference is between those two tables. To do that how to write the sql query ? FYI : these two databases are under the same SQL Server instance.
Table1
------+---------
|name |lastname|
------+---------
|John |rose |
------+---------
|Demy |Sanches |
------+---------
Table2
------+----------
|name2|lastname2|
------+----------
|John |rose |
------+----------
|Demy |Sanches |
------+----------
|Ruby |Core |
------+----------
Then when after comparing table 1 and table 2, it should return Ruby Core from Table2.

Answer 1

Select * from Table1
Except
Select * from Table2
It will show all mismatch records between table1 and table2

Answer 2

Late answer but can be useful to other readers of this thread
Beside other solutions, I can recommend SQL comparison tool called ApexSQL Data Diff.
I know you'd prefer the solution not based on the software, but for other visitors, who may want to do this in an easier way, I strongly suggest reading this article: http://solutioncenter.apexsql.com/how-to-compare-sql-server-database-tables-with-different-names/
The article explains how to use the Object mapping feature in ApexSQL Data Diff, which is particularly useful in situations where two tables share the same name, but their column names are different.
To handle such a case - each column pair needs to be mapped manually in order for the data stored within them to be included when comparing SQL database tables for differences.

Answer 3

If you do an outer join from T1 to T2 you can find rows in the former that are not in the latter by looking for nulls in the T2 values, similarly an outer join of T2 to T1 will give you rows in T2. Union the two together and you get the lot... something like:
SELECT 'Table1' AS TableName, name, lastname FROM
Table1 OUTER JOIN Table2 ON Table1.name = Table2.name2
AND Table1.lastname = Table2.lastname
WHERE Table2.name2 IS NULL
UNION
SELECT 'Table2' AS TableName, name2 as name, lastname2 as lastname FROM
Table2 OUTER JOIN Table1 ON Table2.name2 = Table1.name
AND Table2.lastname2 = Table1.lastname
WHERE Table1.name IS NULL
That's off the top of my head - and I'm a bit rusty :)

Answer 4

If you are using Sql server use a full join. it does exactly the same as Murph said but in one command.
SELECT 'Table1' AS TableName, name, lastname
FROM Table1
FULL JOIN Table2 ON Table1.name = Table2.name2
AND Table1.lastname = Table2.lastname

Answer 5

You could use the CHECKSUM function if you're confident that the data is expressed identically.
Example:
if not OBJECT_ID('Table1', 'Table') is null drop table Table1
if not OBJECT_ID('Table2', 'Table') is null drop table Table2
create table table1
( id int identity(0, 1),
name varchar(128),
lastname varchar(128)
)
create table table2
( id int identity(0, 1),
name varchar(128),
lastname varchar(128)
)
insert into table1 (name, lastname) values ('John', 'rose')
insert into table1 (name, lastname) values ('Demy', 'Sanches')
insert into table2 (name, lastname) values ('John', 'rose')
insert into table2 (name, lastname) values ('Demy', 'Sanches')
insert into table2 (name, lastname) values ('Ruby', 'Core')
select
table2.*
from table1
right outer join table2 on CHECKSUM(table1.name, table1.lastname) = CHECKSUM(table2.name, table2.lastname)
where table1.id is null
See the CHECKSUM MSDN topic for more information.

Answer 6

Try dbForge Data Compare for SQL Server. It can compare and synchronize any database data. Quick, easy, always delivering a correct result. See how it flies on your database!

Answer 7

create table #test
(
Sno INT IDENTITY(1,1),
ExpDate VARCHAR(50),
Amt INT,
Amt1 INT,
Amt2 INT,
SumoAmt INT
)
create table #test1
(
Sno INT IDENTITY(1,1),
ExpDate VARCHAR(50),
Amt INT,
Amt1 INT,
Amt2 INT,
SumoAmt INT
)
INSERT INTO #test(Expdate,Amt,Amt1,Amt2,SumoAmt) values ('30-07-2012',10,20,10,40)
INSERT INTO #test(Expdate,Amt,Amt1,Amt2,SumoAmt) values ('30-07-2012',10,20,20,50)
INSERT INTO #test(Expdate,Amt,Amt1,Amt2,SumoAmt) values ('30-07-2012',10,20,30,60)
INSERT INTO #test(Expdate,Amt,Amt1,Amt2,SumoAmt) values ('30-07-2012',NULL,20,40,70)
INSERT INTO #test1(Expdate,Amt,Amt1,Amt2,SumoAmt) values ('30-07-2012',10,20,10,40)
INSERT INTO #test1(Expdate,Amt,Amt1,Amt2,SumoAmt) values ('30-07-2012',10,20,20,50)
INSERT INTO #test1(Expdate,Amt,Amt1,Amt2,SumoAmt) values ('30-07-2012',10,20,30,60)
INSERT INTO #test1(Expdate,Amt,Amt1,Amt2,SumoAmt) values ('30-07-2012',NULL,20,40,70)
SELECT MIN(TableName) as TableName, Sno,Expdate,Amt,Amt1,Amt2,SumoAmt
FROM
(
SELECT '#test' as TableName,Sno,Expdate,Amt,Amt1,Amt2,SumoAmt
FROM #test
UNION ALL
SELECT '#test1' as TableName,Sno,Expdate,Amt,Amt1,Amt2,SumoAmt
FROM #test1
) tmp
GROUP BY Sno,Expdate,Amt,Amt1,Amt2,SumoAmt
HAVING COUNT(*) = 1
ORDER BY sno

Answer 8

If you want the differences from both the table.
(SELECT *, 'in Table1' AS Comments
FROM Table1
EXCEPT
SELECT * , 'in Table1' AS Comments
FROM Table2)
UNION
(SELECT *, 'in Table2' AS Comments
FROM Table2
EXCEPT
SELECT *, 'in Table2' AS Comments
FROM Table1)

Answer 9

Firefly will do exactly what you're looking for. It lets you build two sql statements then compare the results of the sql queries showing missing rows and data differences. Each query can even come from a different database like oracle / sql server.
http://download.cnet.com/Firefly-Data-Compare-Tool/3000-10254_4-10633690.html?tag=mncol