easy table based update statement???

[Perre Van Wilrijk]

Hello,

I have 2 ways of updating data I'm using often

1) via a cursor on TABLE1 update fields in TABLE2
2) via an some of variables ...

SELECT @var1=FLD1, @var2=FLD2 FROM TABLE1 WHERE FLD-ID = @inputVAR
UPDATE TABLE2
SET FLDx = @var1, FLDy = @var2
WHERE ...

Now I have a system with 2 databases and I need to update table DB2.TAB
based on data in DB1.TAB. Instead of using 1 of the 2 ways I normally use,
I thought it would be much easier to get the required data immediately from
DB1.TAB in the update-statement of DB2.TAB ... but the way to do that
confuses me. I've checked books online and a lot of newsgrouppostings
giving good information but still I keep getting errors like this ...

The column prefix 'x.ADS' does not match with a table name or alias name
used in the query.

while executing the following statement ...

UPDATE DB2.dbo.TAB
SET
FLD1 = x.FLD1,
FLD2 = x.FLD2,
...
FROM DB1.dbo.TAB x, DB2.dbo.ADS
WHERE DB2.dbo.TAB.REFID = x.IDOFTAB1 AND DB2.dbo.TAB.IDOFTAB2 =
@InputParameter

So in DB2.TAB I have a field REFID reffering to the keyfield IDOFTAB1 of
table DB1.TAB
AND I only want to update the row in DB2.TAB with the unique keyfield
IDOFTAB2 equal to variable @InputParameter

Do you see what I'm doing wrong?

--
Thank you,
Kind regards,
Perre Van Wilrijk,
Remove capitals to get my real email address,

[Erland Sommarskog]

Perre Van Wilrijk (pr****@AkoopjeskrantWAY.be) writes:

The column prefix 'x.ADS' does not match with a table name or alias name
used in the query.

while executing the following statement ...

UPDATE DB2.dbo.TAB
SET
FLD1 = x.FLD1,
FLD2 = x.FLD2,
...
FROM DB1.dbo.TAB x, DB2.dbo.ADS
WHERE DB2.dbo.TAB.REFID = x.IDOFTAB1 AND DB2.dbo.TAB.IDOFTAB2 =
@InputParameter

So in DB2.TAB I have a field REFID reffering to the keyfield IDOFTAB1 of
table DB1.TAB
AND I only want to update the row in DB2.TAB with the unique keyfield
IDOFTAB2 equal to variable @InputParameter

The string x.ADS is not in the part of the query you posted. Maybe you
should post the complete query?

But what is really suspect is thaht DB.dbo.ADS is in the FROM lcause,
but not in the WHERE clause. That could cause some unexpectedly bad
performance, as you get a cartesian join.

--
Erland Sommarskog, SQL Server MVP, es****@sommarskog.se

Books Online for SQL Server SP3 at
http://www.microsoft.com/sql/techinf...2000/books.asp

[Perre Van Wilrijk]

Thanks for your reply Mr Erland Sommarskog.

I changed the names of the fields and tables in order to eliminate dutch
databasenames and in order to avoid confusion about the tablename ADS which
appears in both databases, but which isn't an exact copy. DBIngeven is made
only to insert new rows. DBLezen is made only to read data earlier entered
in DBIngeven and other databases. So I'm sorry I made the statement unclear
by replacing tablename ADS by tablename TAB, forgetting to do it
everywhere.in the statement.

This is actually the statement I wrote to synchronize the data, the
statement causing the error "The column prefix 'x.ADS' does not match with a
table name or alias name used in the query.". Might the problem being
caused by the fact that both tables, being in different databases, have the
same name?

CREATE STORED PROCEDURE USP_SYNC
@ADIDLezen int
AS
DECLARE @ER int

UPDATE DBLezen.dbo.ADS
SET
ADS_HR = x.ADS_HR,
ADS_OR = x.ADS_OR,
ADS_VA = x.ADS_VA,
ADS_PH = x.ADS_PH,
ADS_GB = x.ADS_GB,
ADS_TELEPHONE = x.ADS_TELEPHONE,
ADS_GSM = x.ADS_GSM,
ADS_PHOTO = x.ADS_PHOTO,
ADS_USRID= x.ADS_USRID,
ADS_PRICE = x.ADS_PRICE,
ADS_PRICETYPE = x.ADS_PRICETYPE,
ADS_PRICEINDICATION = x.ADS_PRICEINDICATION,
ADS_REGION = x.ADS_REGION,
ADS_KGITEMID = x.ADS_KGITEMID,
ADS_PRODUCTTYPE = x.ADS_PRODUCTTYPE,
ADS_PRODUCTTYPE_WEB = x.ADS_PRODUCTTYPE_WEB,
ADS_FIL = x.ADS_FIL,
ADS_EOONLINE = x.ADS_ONLINE_END,
ADS_CHUS = 'ITOLUPD',
ADS_CHDT = getdate()
FROM DBIngeven.dbo.ADS x, DBLezen.dbo.ADS
WHERE DBLezen.dbo.ADS.ADS_OVID = x.ADS.ADID AND DBLezen.dbo.ADS.ADID =
@ADIDLezen

SET @ER = @@ERROR

Thanks,
Perre.
"Erland Sommarskog" <es****@sommarskog.se> wrote in message
news:Xn**********************@127.0.0.1...

Perre Van Wilrijk (pr****@AkoopjeskrantWAY.be) writes:

The column prefix 'x.ADS' does not match with a table name or alias name
used in the query.

while executing the following statement ...

UPDATE DB2.dbo.TAB
SET
FLD1 = x.FLD1,
FLD2 = x.FLD2,
...
FROM DB1.dbo.TAB x, DB2.dbo.ADS
WHERE DB2.dbo.TAB.REFID = x.IDOFTAB1 AND DB2.dbo.TAB.IDOFTAB2 =
@InputParameter

So in DB2.TAB I have a field REFID reffering to the keyfield IDOFTAB1 of
table DB1.TAB
AND I only want to update the row in DB2.TAB with the unique keyfield
IDOFTAB2 equal to variable @InputParameter

The string x.ADS is not in the part of the query you posted. Maybe you
should post the complete query?

But what is really suspect is thaht DB.dbo.ADS is in the FROM lcause,
but not in the WHERE clause. That could cause some unexpectedly bad
performance, as you get a cartesian join.

--
Erland Sommarskog, SQL Server MVP, es****@sommarskog.se

Books Online for SQL Server SP3 at
http://www.microsoft.com/sql/techinf...2000/books.asp

[Hugo Kornelis]

On Fri, 3 Dec 2004 14:30:43 +0100, Perre Van Wilrijk wrote:

WHERE DBLezen.dbo.ADS.ADS_OVID = x.ADS.ADID AND DBLezen.dbo.ADS.ADID =
@ADIDLezen

Hi Perre,

Change x.ADS.ADID to x.ADID (or x.ADS_ADID - I can only guess here).

Best, Hugo
--

(Remove _NO_ and _SPAM_ to get my e-mail address)

[Erland Sommarskog]

Perre Van Wilrijk (pr****@AkoopjeskrantWAY.be) writes:

I changed the names of the fields and tables in order to eliminate dutch
databasenames and in order to avoid confusion about the tablename ADS
which appears in both databases, but which isn't an exact copy.
Instead you caused confusion. (And Dutch is not a problem to understand,
at least as it's single. Double-dutch may be more difficult...)
This is actually the statement I wrote to synchronize the data, the
statement causing the error "The column prefix 'x.ADS' does not match
with a table name or alias name used in the query.". Might the problem
being caused by the fact that both tables, being in different databases,
have the same name?
No, but because you the alias in the wrong place:
FROM DBIngeven.dbo.ADS x, DBLezen.dbo.ADS
WHERE DBLezen.dbo.ADS.ADS_OVID = x.ADS.ADID AND DBLezen.dbo.ADS.ADID =
@ADIDLezen

x.ADS.ADID would refer to a table ADS owned by the user x.

A tip is to always use aliases. They usually make queries less verbose,
not the least when you use three-part names.
--
Erland Sommarskog, SQL Server MVP, es****@sommarskog.se

Books Online for SQL Server SP3 at
http://www.microsoft.com/sql/techinf...2000/books.asp

[Perre Van Wilrijk]

Thanks Erland,
Thanks Hugo,

Indead I wrote x.ADS.ADID instead of x.ADS_ADID. Unfortenatly the error
messages given back by SQL Server wasn't clear enough for me to locate the
synthax error I made. Great you saw it without knowing my table and field
names. Sorry to have bothered you with such a stupid mistake.

I also made an alias for DBLezen making the WHERE-clause better readable and
maintainable.
A little bit strange now I can't use the y alias in the SET clause (eg SET
y.ADS_HR = x.ADS_HR, ...), I guess that's because the first field name
refers to the table name after the UPDATE-word, which doesn't seem to be
aliasable. So this on works fine ...

UPDATE DBLezen.dbo.ADS
SET
ADS_HR = x.ADS_HR,
ADS_OR = x.ADS_OR,
ADS_VA = x.ADS_VA,
ADS_PH = x.ADS_PH,
ADS_GB = x.ADS_GB,
ADS_TELEPHONE = x.ADS_TELEPHONE,
ADS_GSM = x.ADS_GSM,
ADS_PHOTO = x.ADS_PHOTO,
ADS_USRID= x.ADS_USRID,
ADS_PRICE = x.ADS_PRICE,
ADS_PRICETYPE = x.ADS_PRICETYPE,
ADS_PRICEINDICATION = x.ADS_PRICEINDICATION,
ADS_REGION = x.ADS_REGION,
ADS_KGITEMID = x.ADS_KGITEMID,
ADS_PRODUCTTYPE = x.ADS_PRODUCTTYPE,
ADS_PRODUCTTYPE_WEB = x.ADS_PRODUCTTYPE_WEB,
ADS_FIL = x.ADS_FIL,
ADS_EOONLINE = x.ADS_ONLINE_END,
ADS_CHUS = 'ITOLUPD',
ADS_CHDT = getdate()
FROM DBIngeven.dbo.ADS x, DBLezen.dbo.ADS y
WHERE y.ADS_OVID = x.ADS_ADID AND y.ADS_ADID = @ADIDLezen

"Erland Sommarskog" <es****@sommarskog.se> wrote in message
news:Xn**********************@127.0.0.1...

Perre Van Wilrijk (pr****@AkoopjeskrantWAY.be) writes:

I changed the names of the fields and tables in order to eliminate dutch
databasenames and in order to avoid confusion about the tablename ADS
which appears in both databases, but which isn't an exact copy.

Instead you caused confusion. (And Dutch is not a problem to understand,
at least as it's single. Double-dutch may be more difficult...)

This is actually the statement I wrote to synchronize the data, the
statement causing the error "The column prefix 'x.ADS' does not match
with a table name or alias name used in the query.". Might the problem
being caused by the fact that both tables, being in different databases,
have the same name?

No, but because you the alias in the wrong place:

FROM DBIngeven.dbo.ADS x, DBLezen.dbo.ADS
WHERE DBLezen.dbo.ADS.ADS_OVID = x.ADS.ADID AND DBLezen.dbo.ADS.ADID = @ADIDLezen

x.ADS.ADID would refer to a table ADS owned by the user x.

A tip is to always use aliases. They usually make queries less verbose,
not the least when you use three-part names.
--
Erland Sommarskog, SQL Server MVP, es****@sommarskog.se

Books Online for SQL Server SP3 at
http://www.microsoft.com/sql/techinf...2000/books.asp

[Hugo Kornelis]

On Tue, 7 Dec 2004 13:55:55 +0100, Perre Van Wilrijk wrote:

(snip)

I also made an alias for DBLezen making the WHERE-clause better readable and
maintainable.
A little bit strange now I can't use the y alias in the SET clause (eg SET
y.ADS_HR = x.ADS_HR, ...), I guess that's because the first field name
refers to the table name after the UPDATE-word, which doesn't seem to be
aliasable. So this on works fine ...

UPDATE DBLezen.dbo.ADS
SET
ADS_HR = x.ADS_HR,

(snip)

This should work as well:

UPDATE y
SET
ADS_HR = x.ADS_HR,
(...)
FROM DBIngeven.dbo.ADS x, DBLezen.dbo.ADS y
WHERE y.ADS_OVID = x.ADS_ADID AND y.ADS_ADID = @ADIDLezen

Personally, I prefer to always use the UPDATE .. FROM syntax this way, so
I won't forget to use it if a self-join is included (than it becomes
mandatory to use the alias in the UPDATE clause).

Best, Hugo
--

(Remove _NO_ and _SPAM_ to get my e-mail address)

[Erland Sommarskog]

Perre Van Wilrijk (pr****@AkoopjeskrantWAY.be) writes:

Indead I wrote x.ADS.ADID instead of x.ADS_ADID. Unfortenatly the error
messages given back by SQL Server wasn't clear enough for me to locate the
synthax error I made.

It's kind of difficult for SQL Server to second-guess what you really meant.

But it is true that the error messages from SQL Server are not always
crystal clear. When it comes to true parsing errors, the obscureness of
the messages partly comes from the too rich syntax of T-SQL. A typo can
lead to some legal syntax SQL that you are not aware of, but then lead
a syntax error further ahead.

For the error message you got, I guess the main problem is that the
message points to the first line in the UPDATE statement, instead of
the line where the error is. That makes it more difficult to spot the
error.

--
Erland Sommarskog, SQL Server MVP, es****@sommarskog.se

Books Online for SQL Server SP3 at
http://www.microsoft.com/sql/techinf...2000/books.asp

[perre van wilrijk]

> It's kind of difficult for SQL Server to second-guess what you really
meant.

But it is true that the error messages from SQL Server are not always
crystal clear. When it comes to true parsing errors, the obscureness of the messages partly comes from the too rich syntax of T-SQL. A typo can lead to some legal syntax SQL that you are not aware of, but then lead a syntax error further ahead.

It might not be easy to parse especially my code :-)
I can imagine that.
I once believed I could give people using my programs always clear
messages, for each kind of problem. We all have to learn.