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Hi, how can i return a 0 if my query returns no results?
I'm trying to do this because i have a subquery inside a query but if the subquery returns no values then the main query also returns nothing.
I'm using MySQL 5.
Thanks in advance.
-- modified at 20:24 Saturday 15th July, 2006
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sounds like you are using an inner join between your queries? try a left or right join.
or post you sql and you may get a better response
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Hi, you're right, there's a inner join inside my query, check it out, hope you understand the query and the problem:
select SUM((t1.valor + t1.total) - t2sum) from consultas as t1 inner join (select consulta, SUM(cantidad_pagada) as t2sum from pagos_consultas where fecha_pago='2006-07-05' group by consulta) as t2 on t2.consulta=t1.id where t1.nula=0 and t1.pagada=0 and t1.fecha='2006-07-05'
I had no idea about left and right join so i went to http://www.w3schools.com/sql/sql_join.asp and took a read, the left join is the one for me! but this will return NULL in the second table when there're no matches and if you look at my query in "(t1.valor + t1.total) - t2sum" i do a " - " operation and i cant reduce a number with a null value or can i? i must replace that null for a 0.
Thanx man.
-- modified at 15:42 Monday 17th July, 2006
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isnull( field, newValue) works in SQL Server and NVL in Oracle.
A man said to the universe:
"Sir I exist!"
"However," replied the Universe, "The fact has not created in me A sense of obligation."
-- Stephen Crane
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you can use also use the coalesce() function to remove the Null value.
eg.
replace - t2sum
with
- coalesce(t2sum,0)
is a nice little function is coalesce as you can list as many variables as you want, it works through from left to right until it finds a non null value and uses that.
sounds like its the same as the isNull() function mentioned in previous post.
its a SQL server only function though!
-- modified at 4:23 Tuesday 18th July, 2006
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Thanx man. You really did it! thanx.
I was reading mysql 5 manual and there's a ISNULL(expression) function but it returns 1 if the expression is null and 0 if not null (the inverse of what i need), but, thank god there's also a IS NOT NULL wich return 1 when not null and 0 when null, so i have now many ways to acomplish my objective.
[ADDED] Reading about COALESCE() in mysql 5, and it works in a different manner than the normal ISNULL for MS SQL SERVER and others...COALESCE does not replace any null values nor it has a fixed return value, COALESCE() in mysql takes a list of values as a parameter and returns the first Not NULL value and returns NULL if any of the values in the list are not null, ie:
mysql> SELECT COALESCE(NULL,NULL,1,'hello','world',25);<br />
-> 1<br />
mysql> SELECT COALESCE(NULL,NULL,NULL);<br />
-> NULL
So, all i have to do in my case is: COALESCE(mycolumnvalue,0) and if the query returns mycolumnvalue null then it will return 0.
Bye,
-- modified at 14:52 Tuesday 18th July, 2006
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hi all,
greetings.I have a doubt regarding the creation and execution of stored procedures.Can any one tell me how to create a stored procedure in MS Access database and how to execute it?
Thanks in advance.
Babu
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You need to create an Access Project. You may refer to my article on this at:
http://www.angelfire.com/vt2/hodentek/[^]
This being said, Access 2003  does not support Access project with SQL 2005 Server.
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Simple answer - NO
unless as mentioned by someone else you are creating an MS access project to hook up to a sql server, if so its just a SQL server stored proc
But if its a normal access database you should be able to write your own scalar functions (single return value), but you can not write functions that will return a recordset. unless the consumer of the recordset is another vba function...
hope that makes sense, I've not had my coffee yet!
Mr ra ra
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Hi
I am using following stored procedure
-----------------------------------
set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[GetUserControlTemplateCode]
@product_id int,
@genmask_code nvarchar(max) output
AS
BEGIN
SET NOCOUNT ON;
Select dbo.cp_product.product_type, dbo.cp_genmask.genmask_code
from dbo.cp_genmask inner join dbo.cp_product
on dbo.cp_genmask.genmask_product_type=dbo.cp_product.product_type
where dbo.cp_product.product_id=@product_id
END
--------------------------------
when I execute the above code using
exec GetUserControlTemplateCode 1,'x'
I get correct values for x i.e. output parameter.
My code behind to call stored procedure is as follows
---------------------------------
protected void Page_Load(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["sConnectionString2"].ConnectionString);
SqlCommand Com = con.CreateCommand();
Com.CommandType = CommandType.StoredProcedure;
Com.CommandText = "GetUserControlTemplateCode";
//Create parameter object to provide input
SqlParameter parInput = Com.Parameters.Add("@product_id", SqlDbType.Int);
parInput.Direction = ParameterDirection.Input;
parInput.Value = nProductID;
// Create parameter to hold output
SqlParameter parOutput = Com.Parameters.Add("@genmask_code", SqlDbType.NVarChar,300);
parOutput.Direction = ParameterDirection.Output;
//Open the connection
con.Open();
//Execute command
try
{
Com.ExecuteNonQuery();
}
catch (Exception ex)
{
Response.Write(ex.ToString());
}
string sTemplateCode = Convert.ToString(parOutput.Value);
sTemplateCode = sTemplateCode.Replace("ProductID", nProductID.ToString());
Control myControl = ParseControl(sTemplateCode);
PlaceHolderForProducts.Controls.Add(myControl);
con.Close();
}
-----------------------------------
when I execute the code, i do not get any exception, but the value of output parameter is null.
Can someone please help me to understand whats missing here?
Thanks.
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I did not see the statement setting value for @genmask_code so infact, it have no return value. Also I think exec GetUserControlTemplateCode 1,'x' will not work because of lacking OUTPUT modifier. It should be:
<br />
exec GetUserControlTemplateCode 1, @x OUTPUT<br />
print @x<br />
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Colin Angus Mackay wrote: NOTE: You should only do this if you expect the SELECT statement to retrieve only one row.
You won't get an error if it does retrieve more than one row, but if it does, you'll simply get the value from the last row returned by the query. Unless you put an ORDER BY clause in, however, which row that is will be unpredictable.
If no rows are returned, the value of the variable will be unchanged.
Stability. What an interesting concept. -- Chris Maunder
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Thanks for your replies,
I changed my stored procedure as follows to assign the value to output variable:
ALTER PROCEDURE [dbo].[GetUserControlTemplateCode]
@product_id int,
@genmask_code nvarchar(max) output
AS
BEGIN
SET NOCOUNT ON;
Select dbo.cp_product.product_type, @genmask_code=dbo.cp_genmask.genmask_code
from dbo.cp_genmask inner join dbo.cp_product
on dbo.cp_genmask.genmask_product_type=dbo.cp_product.product_type
where dbo.cp_product.product_id=@product_id
END
when I execute this I get following error:
A SELECT statement that assigns a value to a variable must not be combined with data-retrieval operations.
where should I do data assignment operation?
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I changed the code as follows
ALTER PROCEDURE [dbo].[GetUserControlTemplateCode]
@product_id int,
@genmask_code nvarchar(max) output
AS
BEGIN
SET NOCOUNT ON;
Declare @product_type int
Select b.product_type, @genmask_code=dbo.cp_genmask.genmask_code
from dbo.cp_genmask as a inner join dbo.cp_product as b
on a.genmask_product_type=b.product_type
where b.product_id=@product_id
END
I executed this code using using
exec GetUserControlTemplateCode 1, @genmask_code output
print @genmask_code
It gives me message as command executed successfully, but I can not see any data in output window. Again when I call this procedure from code behind code it shows null value...
Please suggest where I am wrong.
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My evaluation copy ran-out and I uninstalled the previous and
installed another evaluation edition. The installation was
successful. I created a SSIS package importing a table from Oracle
10G XE to the SQL 2005 on my machine. I saved the package on
the server. The SSIS service is running but when I try to refresh
the node, I get this message. The help link leads to no where(Hello, Microsoft!):
--------------------------------------
TITLE: Microsoft SQL Server Management Studio
------------------------------
Failed to retrieve data for this request.
(Microsoft.SqlServer.SmoEnum)
For help, click: http://go.microsoft.com/fwlink?
ProdName=Microsoft+SQL+Server&LinkId=20476
------------------------------
ADDITIONAL INFORMATION:
Login timeout expired
An error has occurred while establishing a connection to the
server. When connecting to SQL Server 2005, this failure may be
caused by the fact that under the default settings SQL Server
does not allow remote connections.
TCP Provider: No connection could be made because the target
machine actively refused it. (Microsoft SQL Native Client)
------------------------------
Login timeout expired
An error has occurred while establishing a connection to the
server. When connecting to SQL Server 2005, this failure may be
caused by the fact that under the default settings SQL Server
does not allow remote connections.
TCP Provider: No connection could be made because the target
machine actively refused it. (Microsoft SQL Native Client)
------------------------------
My efforts so far:
:-DI have verified the items in the Surface area screen, everythign
looks good.
SSIS service has started.
:-DBoth the Network Server TCP/IP dynmaic port and the SQL
Client TCP/IP dynamic port are the same.
:-DI have no problem logging in to any of the services.
 But I get this message.
I tried to create a package from Visual Studio, but that also did
not succeed.
 In my previous set up, I created perhaps 1/ 2 dozen different
packages.
I am puzzzled.
I appreciate if some one could throw some light.
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One of my statements is wrong.
I could create a package in Visual Studio, but I could not access this in SSIS.
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mysorian wrote: My evaluation copy ran-out and I uninstalled the previous and installed another evaluation edition
Do you want to read that again and guess what a probably cause of the problem is? Do you think it's entirely possible that the new installation knows that you already had an evaluation edition installed and it expired?
Dave Kreskowiak
Microsoft MVP - Visual Basic
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The evaluation edition was completely removed as any new install flags any remnants that needs removing. I was instructed during new install to move my 'Data' to another location which I did. The packages although saved to 'Sql Server' had created 'dtsx' files as well.
However, from VS 2005 I can create a package, but cannot see, or access it in the SQL 2005 Management Studio. I wish error messages could have been more friendly [see my comments in the article on SQLCMD].
I am technical writer and I routinely, meticulously document what I do. Here are my recent articles.
Thnaks for your fast response.
Moving Data from SQL Server 2000 to SQL Server 2005
Querying Databases in SQL Server 2005
SQL2000 Data Transfer is a snap with SQL 2005
On using the SQLCMD in SQL 2005 Server
Generating and Hosting a SQL Server Reporting Services Report Using SQL Server 2005 Business Intelligence Development Studio
These and other articles may be found at:http://www.angelfire.com/vt2/hodentek/[^]
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What is the Differance between '@variable' and '@@variable' in SQL syntax?
Thanks
Sampath
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@variable are local variables
@@WHATEVER are system variables
--EricDV Sig---------
Some problems are so complex that you have to be highly intelligent and well informed just to be undecided about them.
- Laurence J. Peters
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Hi
My table has one column "vat_percentage" as numeric(2,2) data type.
when I try to insert values using
INSERT INTO [dbo].[cp_vat]
([vat_text],[vat_percentage],[vat_valid_from],[vat_valid_to])
values
('test',10.2,05/2005/05,05/05/2007)
I get an error as
Arithmetic overflow error converting numeric to data type numeric.
can someone pls help me?
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That will be your dates. Best practice is to use ISO format dates, yyyymmdd, as these are not sensitive to the selected locale, so you would write your statement as:
INSERT INTO [dbo].[cp_vat]
([vat_text],[vat_percentage],[vat_valid_from],[vat_valid_to])
values
('test',10.2,'20050505','20070505')Note that date literals are entered as strings, not numbers - if you pass a number, it will be treated as the binary representation and you'll get the wrong answer.
If you're passing these dates in from application code, you should use parameterised queries and the appropriate Parameters collection.
Stability. What an interesting concept. -- Chris Maunder
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Mik, I used the string given by u, but still the error persists 
Arithmetic overflow error converting numeric to data type numeric.
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What Mik said about date literals, is right.
The precision is the total number of digits in the number, and the scale is the number of digits to right of the decimal point in the number. see here[^]
You defined the field vat_percentage as numeric (2,2), means numeric field with precision 2 and scale 2. Now in this scenario the problem is with the numeric value that you given, which is 10.2, even if you enter 1 you will get the same error message.
With your defined precision and scale you can only enter values like this: 0.23. If you entered .23987, it will round to .24
Or Alternatively change the field definition to numeric(4,2)
that is total number of digits will be 4. Among them 2 digits will be at right of the decimal point.
Hope this would solve your problem.
Regards
_____________________________
Success is not something to wait for, its something to work for.
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