I'm new to PostgreSQL. I have a winforms app thats calling to a PostgreSQL db. Instead of passing in the query, id rather use PostgreSQL paramaterised stored procedures. I am able to all and get a return for a parameterless stored procedure but when I add parameters and execute the call, I get an error saying that coloumn userId doesn't exist.
userid is the parameter.
On PostgreSQL, when creating the sp, I also create an IN argument with that thats same rype and name.
What am I missing here?
The sql is a simple:
select * from public.users u where u.userid = userid.
use it to identify a parameter in SQL:
Select * from public.users u where u.userid = #userid
You indicated that you "create an IN argument with that thats same (t)ype and name". That is not quite what you do want to do. While you do want the type to be the same the name must either different or qualified by the function name. If it the same you will get all rows as the intended parameter name will be interpreted as the column name; basically resulting in:
Select * from table_name where column_name = column_name;
Which is true whenever the value isn't null. Now there are 2 approaches, using userid and assuming its unique:
create or replace function get_user(userid_in users.userid%type)
returns setof users
language sql
as $$
select *
from users where userid = userid_in ;
$$;
OR
create or replace function get_user(userid users.userid%type)
returns setof users
language sql
as $$
select *
from users where userid = get_user.userid ;
$$;
How to pass an array into a SQL Server stored procedure?
For example, I have a list of employees. I want to use this list as a table and join it with another table. But the list of employees should be passed as parameter from C#.
SQL Server 2016 (or newer)
You can pass in a delimited list or JSON and use STRING_SPLIT() or OPENJSON().
STRING_SPLIT():
CREATE PROCEDURE dbo.DoSomethingWithEmployees
#List varchar(max)
AS
BEGIN
SET NOCOUNT ON;
SELECT value FROM STRING_SPLIT(#List, ',');
END
GO
EXEC dbo.DoSomethingWithEmployees #List = '1,2,3';
OPENJSON():
CREATE PROCEDURE dbo.DoSomethingWithEmployees
#List varchar(max)
AS
BEGIN
SET NOCOUNT ON;
SELECT value FROM OPENJSON(CONCAT('["',
REPLACE(STRING_ESCAPE(#List, 'JSON'),
',', '","'), '"]')) AS j;
END
GO
EXEC dbo.DoSomethingWithEmployees #List = '1,2,3';
I wrote more about this here:
Handling an unknown number of parameters in SQL Server
Ordered String Splitting in SQL Server with OPENJSON
SQL Server 2008 (or newer)
First, in your database, create the following two objects:
CREATE TYPE dbo.IDList
AS TABLE
(
ID INT
);
GO
CREATE PROCEDURE dbo.DoSomethingWithEmployees
#List AS dbo.IDList READONLY
AS
BEGIN
SET NOCOUNT ON;
SELECT ID FROM #List;
END
GO
Now in your C# code:
// Obtain your list of ids to send, this is just an example call to a helper utility function
int[] employeeIds = GetEmployeeIds();
DataTable tvp = new DataTable();
tvp.Columns.Add(new DataColumn("ID", typeof(int)));
// populate DataTable from your List here
foreach(var id in employeeIds)
tvp.Rows.Add(id);
using (conn)
{
SqlCommand cmd = new SqlCommand("dbo.DoSomethingWithEmployees", conn);
cmd.CommandType = CommandType.StoredProcedure;
SqlParameter tvparam = cmd.Parameters.AddWithValue("#List", tvp);
// these next lines are important to map the C# DataTable object to the correct SQL User Defined Type
tvparam.SqlDbType = SqlDbType.Structured;
tvparam.TypeName = "dbo.IDList";
// execute query, consume results, etc. here
}
SQL Server 2005
If you are using SQL Server 2005, I would still recommend a split function over XML. First, create a function:
CREATE FUNCTION dbo.SplitInts
(
#List VARCHAR(MAX),
#Delimiter VARCHAR(255)
)
RETURNS TABLE
AS
RETURN ( SELECT Item = CONVERT(INT, Item) FROM
( SELECT Item = x.i.value('(./text())[1]', 'varchar(max)')
FROM ( SELECT [XML] = CONVERT(XML, '<i>'
+ REPLACE(#List, #Delimiter, '</i><i>') + '</i>').query('.')
) AS a CROSS APPLY [XML].nodes('i') AS x(i) ) AS y
WHERE Item IS NOT NULL
);
GO
Now your stored procedure can just be:
CREATE PROCEDURE dbo.DoSomethingWithEmployees
#List VARCHAR(MAX)
AS
BEGIN
SET NOCOUNT ON;
SELECT EmployeeID = Item FROM dbo.SplitInts(#List, ',');
END
GO
And in your C# code you just have to pass the list as '1,2,3,12'...
I find the method of passing through table valued parameters simplifies the maintainability of a solution that uses it and often has increased performance compared to other implementations including XML and string splitting.
The inputs are clearly defined (no one has to guess if the delimiter is a comma or a semi-colon) and we do not have dependencies on other processing functions that are not obvious without inspecting the code for the stored procedure.
Compared to solutions involving user defined XML schema instead of UDTs, this involves a similar number of steps but in my experience is far simpler code to manage, maintain and read.
In many solutions you may only need one or a few of these UDTs (User defined Types) that you re-use for many stored procedures. As with this example, the common requirement is to pass through a list of ID pointers, the function name describes what context those Ids should represent, the type name should be generic.
Based on my experience, by creating a delimited expression from the employeeIDs, there is a tricky and nice solution for this problem. You should only create an string expression like ';123;434;365;' in-which 123, 434 and 365 are some employeeIDs. By calling the below procedure and passing this expression to it, you can fetch your desired records. Easily you can join the "another table" into this query. This solution is suitable in all versions of SQL server. Also, in comparison with using table variable or temp table, it is very faster and optimized solution.
CREATE PROCEDURE dbo.DoSomethingOnSomeEmployees #List AS varchar(max)
AS
BEGIN
SELECT EmployeeID
FROM EmployeesTable
-- inner join AnotherTable on ...
where #List like '%;'+cast(employeeID as varchar(20))+';%'
END
GO
Use a table-valued parameter for your stored procedure.
When you pass it in from C# you'll add the parameter with the data type of SqlDb.Structured.
See here: http://msdn.microsoft.com/en-us/library/bb675163.aspx
Example:
// Assumes connection is an open SqlConnection object.
using (connection)
{
// Create a DataTable with the modified rows.
DataTable addedCategories =
CategoriesDataTable.GetChanges(DataRowState.Added);
// Configure the SqlCommand and SqlParameter.
SqlCommand insertCommand = new SqlCommand(
"usp_InsertCategories", connection);
insertCommand.CommandType = CommandType.StoredProcedure;
SqlParameter tvpParam = insertCommand.Parameters.AddWithValue(
"#tvpNewCategories", addedCategories);
tvpParam.SqlDbType = SqlDbType.Structured;
// Execute the command.
insertCommand.ExecuteNonQuery();
}
You need to pass it as an XML parameter.
Edit: quick code from my project to give you an idea:
CREATE PROCEDURE [dbo].[GetArrivalsReport]
#DateTimeFrom AS DATETIME,
#DateTimeTo AS DATETIME,
#HostIds AS XML(xsdArrayOfULong)
AS
BEGIN
DECLARE #hosts TABLE (HostId BIGINT)
INSERT INTO #hosts
SELECT arrayOfUlong.HostId.value('.','bigint') data
FROM #HostIds.nodes('/arrayOfUlong/u') as arrayOfUlong(HostId)
Then you can use the temp table to join with your tables.
We defined arrayOfUlong as a built in XML schema to maintain data integrity, but you don't have to do that. I'd recommend using it so here's a quick code for to make sure you always get an XML with longs.
IF NOT EXISTS (SELECT * FROM sys.xml_schema_collections WHERE name = 'xsdArrayOfULong')
BEGIN
CREATE XML SCHEMA COLLECTION [dbo].[xsdArrayOfULong]
AS N'<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="arrayOfUlong">
<xs:complexType>
<xs:sequence>
<xs:element maxOccurs="unbounded"
name="u"
type="xs:unsignedLong" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>';
END
GO
Context is always important, such as the size and complexity of the array. For small to mid-size lists, several of the answers posted here are just fine, though some clarifications should be made:
For splitting a delimited list, a SQLCLR-based splitter is the fastest. There are numerous examples around if you want to write your own, or you can just download the free SQL# library of CLR functions (which I wrote, but the String_Split function, and many others, are completely free).
Splitting XML-based arrays can be fast, but you need to use attribute-based XML, not element-based XML (which is the only type shown in the answers here, though #AaronBertrand's XML example is the best as his code is using the text() XML function. For more info (i.e. performance analysis) on using XML to split lists, check out "Using XML to pass lists as parameters in SQL Server" by Phil Factor.
Using TVPs is great (assuming you are using at least SQL Server 2008, or newer) as the data is streamed to the proc and shows up pre-parsed and strongly-typed as a table variable. HOWEVER, in most cases, storing all of the data in DataTable means duplicating the data in memory as it is copied from the original collection. Hence using the DataTable method of passing in TVPs does not work well for larger sets of data (i.e. does not scale well).
XML, unlike simple delimited lists of Ints or Strings, can handle more than one-dimensional arrays, just like TVPs. But also just like the DataTable TVP method, XML does not scale well as it more than doubles the datasize in memory as it needs to additionally account for the overhead of the XML document.
With all of that said, IF the data you are using is large or is not very large yet but consistently growing, then the IEnumerable TVP method is the best choice as it streams the data to SQL Server (like the DataTable method), BUT doesn't require any duplication of the collection in memory (unlike any of the other methods). I posted an example of the SQL and C# code in this answer:
Pass Dictionary to Stored Procedure T-SQL
As others have noted above, one way to do this is to convert your array to a string and then split the string inside SQL Server.
As of SQL Server 2016, there's a built-in way to split strings called
STRING_SPLIT()
It returns a set of rows that you can insert into your temp table (or real table).
DECLARE #str varchar(200)
SET #str = "123;456;789;246;22;33;44;55;66"
SELECT value FROM STRING_SPLIT(#str, ';')
would yield:
value
-----
123
456
789
246
22
33
44
55
66
If you want to get fancier:
DECLARE #tt TABLE (
thenumber int
)
DECLARE #str varchar(200)
SET #str = "123;456;789;246;22;33;44;55;66"
INSERT INTO #tt
SELECT value FROM STRING_SPLIT(#str, ';')
SELECT * FROM #tt
ORDER BY thenumber
would give you the same results as above (except the column name is "thenumber"), but sorted. You can use the table variable like any other table, so you can easily join it with other tables in the DB if you want.
Note that your SQL Server install has to be at compatibility level 130 or higher in order for the STRING_SPLIT() function to be recognized. You can check your compatibility level with the following query:
SELECT compatibility_level
FROM sys.databases WHERE name = 'yourdatabasename';
Most languages (including C#) have a "join" function you can use to create a string from an array.
int[] myarray = {22, 33, 44};
string sqlparam = string.Join(";", myarray);
Then you pass sqlparam as your parameter to the stored procedure above.
This will help you. :) Follow the next steps,
Open the Query Editor
Copy Paste the following code as it is, it will create the Function which converts the String to Int
CREATE FUNCTION dbo.SplitInts
(
#List VARCHAR(MAX),
#Delimiter VARCHAR(255)
)
RETURNS TABLE
AS
RETURN ( SELECT Item = CONVERT(INT, Item) FROM
( SELECT Item = x.i.value('(./text())[1]', 'varchar(max)')
FROM ( SELECT [XML] = CONVERT(XML, '<i>'
+ REPLACE(#List, #Delimiter, '</i><i>') + '</i>').query('.')
) AS a CROSS APPLY [XML].nodes('i') AS x(i) ) AS y
WHERE Item IS NOT NULL
);
GO
Create the Following stored procedure
CREATE PROCEDURE dbo.sp_DeleteMultipleId
#List VARCHAR(MAX)
AS
BEGIN
SET NOCOUNT ON;
DELETE FROM TableName WHERE Id IN( SELECT Id = Item FROM dbo.SplitInts(#List, ','));
END
GO
Execute this SP Using exec sp_DeleteId '1,2,3,12' this is a string of Id's which you want to delete,
You can convert your array to string in C# and pass it as a Stored Procedure parameter as below,
int[] intarray = { 1, 2, 3, 4, 5 };
string[] result = intarray.Select(x=>x.ToString()).ToArray();
SqlCommand command = new SqlCommand();
command.Connection = connection;
command.CommandText = "sp_DeleteMultipleId";
command.CommandType = CommandType.StoredProcedure;
command.Parameters.Add("#Id",SqlDbType.VARCHAR).Value=result ;
This will delete multiple rows in a single stored proc call. All the best.
There is no support for array in sql server but there are several ways by which you can pass collection to a stored proc .
By using datatable
By using XML.Try converting your collection in an xml format and then pass it as an input to a stored procedure
The below link may help you
passing collection to a stored procedure
Starting in SQL Server 2016 you can bring the list in as an NVARCHAR() and use OPENJSON
DECLARE #EmployeeList nvarchar(500) = '[1,2,15]'
SELECT *
FROM Employees
WHERE ID IN (SELECT VALUE FROM OPENJSON(#EmployeeList ))
I've been searching through all the examples and answers of how to pass any array to sql server without the hassle of creating new Table type,till i found this linK, below is how I applied it to my project:
--The following code is going to get an Array as Parameter and insert the values of that
--array into another table
Create Procedure Proc1
#UserId int, //just an Id param
#s nvarchar(max) //this is the array your going to pass from C# code to your Sproc
AS
declare #xml xml
set #xml = N'<root><r>' + replace(#s,',','</r><r>') + '</r></root>'
Insert into UserRole (UserID,RoleID)
select
#UserId [UserId], t.value('.','varchar(max)') as [RoleId]
from #xml.nodes('//root/r') as a(t)
END
Hope you enjoy it
Starting in SQL Server 2016 you can simply use split string
Example:
WHERE (#LocationId IS NULL OR Id IN (SELECT items from Split_String(#LocationId, ',')))
CREATE TYPE dumyTable
AS TABLE
(
RateCodeId int,
RateLowerRange int,
RateHigherRange int,
RateRangeValue int
);
GO
CREATE PROCEDURE spInsertRateRanges
#dt AS dumyTable READONLY
AS
BEGIN
SET NOCOUNT ON;
INSERT tblRateCodeRange(RateCodeId,RateLowerRange,RateHigherRange,RateRangeValue)
SELECT *
FROM #dt
END
It took me a long time to figure this out, so in case anyone needs it...
This is based on the SQL 2005 method in Aaron's answer, and using his SplitInts function (I just removed the delim param since I'll always use commas). I'm using SQL 2008 but I wanted something that works with typed datasets (XSD, TableAdapters) and I know string params work with those.
I was trying to get his function to work in a "where in (1,2,3)" type clause, and having no luck the straight-forward way. So I created a temp table first, and then did an inner join instead of the "where in". Here is my example usage, in my case I wanted to get a list of recipes that don't contain certain ingredients:
CREATE PROCEDURE dbo.SOExample1
(
#excludeIngredientsString varchar(MAX) = ''
)
AS
/* Convert string to table of ints */
DECLARE #excludeIngredients TABLE (ID int)
insert into #excludeIngredients
select ID = Item from dbo.SplitInts(#excludeIngredientsString)
/* Select recipies that don't contain any ingredients in our excluded table */
SELECT r.Name, r.Slug
FROM Recipes AS r LEFT OUTER JOIN
RecipeIngredients as ri inner join
#excludeIngredients as ei on ri.IngredientID = ei.ID
ON r.ID = ri.RecipeID
WHERE (ri.RecipeID IS NULL)
I want to define a function to get "order number" parameter and return "last name" of the customer.these two parameters are in different tables i am using inner join.
the errors i am getting are: Incorrect syntax near (.
Incorrect syntax near the keyword RETURN.
Must declare the scalar variable #FindingLastName.
my code:
com.CommandText = "Create function Sales.FindingLastName (#OrderNumber varchar(10)) Returns nvarchar(50) As Begin Declare #FindingLastName(Select LastName from Sales.OrderDetails INNER JOIN Sales.Customers RETURN #FindingLastName END GO)";
com.Connection = con;
MessageBox.Show(com.ExecuteNonQuery().ToString());
You have lot of things missed in your SQL Syntax. Have a look at below SQL Syntax Change the ColumnNameto actual columnnames in join statement. May be you want to modify the select condition accordingly by adding WHERE clause.
Create function Sales.FindingLastName
(#OrderNumber varchar(10))
Returns nvarchar(50) As
Begin
Declare #FindingLastName varchar(50) =
(Select LastName from Sales.OrderDetails O INNER JOIN Sales.Customers C ON C.ColumnName =O.ColumnName)
RETURN #FindingLastName
END
One more question You can run this only once. Once the function is created, you can't create same function again. So i doubt are you sure you want to do it this way via c#?? !!
For more details on User Defined function in SQL Refer THIS LINK
What stands out there is the GO. Firstly, GO is not SQL. It only exists to tools like SSMS (etc), which use it to split a long script into separate commands. Inside an actual command, it is simply a syntax error. Consequently, GO can never appear inside nesting such as parenthesis, or a BEGIN / END block.
Basically, remove the GO.
However, it is pretty rare to use DDL inside ADO.NET, unless part of an automated schema migration tool etc.
I'm no hero with SQL, but i think this should work
Create function Sales.FindingLastName (#OrderNumber varchar(10))
RETURNS nvarchar(50)
As
RETURN
(
Select LastName
from Sales.OrderDetails INNER JOIN Sales.Customers
);
I am using Entity Framework with C# to make a Silverlight application. I have written some stored procedures which perform database intensive operations and I need to call them from Entity Framework after passing some parameters. In one of the steps, the users select a list of items for which they would need more details. This list of items (in the form of an array of integer IDs) need to be passed to the stored procedure to retrieve more information about those IDs. How do I pass this parameter to the stored procedure?
You can't pass table-valued parameters to SQL with the Entity Framework.
What you can do is create a delimited string like "1|2|3|4" and create a Split function in SQL that will return a table.
CREATE FUNCTION dbo.Split
(
#RowData nvarchar(2000),
#SplitOn nvarchar(5)
)
RETURNS #RtnValue table
(
Id int identity(1,1),
Data nvarchar(100)
)
AS
BEGIN
Declare #Cnt int
Set #Cnt = 1
While (Charindex(#SplitOn,#RowData)>0)
Begin
Insert Into #RtnValue (data)
Select
Data = ltrim(rtrim(Substring(#RowData,1,Charindex(#SplitOn,#RowData)-1)))
Set #RowData = Substring(#RowData,Charindex(#SplitOn,#RowData)+1,len(#RowData))
Set #Cnt = #Cnt + 1
End
Insert Into #RtnValue (data)
Select Data = ltrim(rtrim(#RowData))
Return
END
Then if you need to do something like select all items from a table based on what is in the delimited string passed to your proc:
SELECT * FROM SomeTable WHERE Id IN (SELECT Id FROM dbo.Split(#DelStr, '|'))
If you are using SQL Server, which I assume is the case, you can create use a table valued parameter to do what you wish. Using a table valued parameter prevents you from parsing an input parameter within the stored procedure and removes the threat of a SQL injection attack by eliminating the use of dynamic SQL.
Here is a great blog article that covers how to do what you wish to do.
Using Table-Valued Parameters in SQL Server 2008 and C#
Is this what you were looking for?
For example， the users of our app want to search products by entering a keyword of productName.
The Products table of the sql server database contains about 10 million records.
Are there any better and higher-performance search methods to implement instead of productName.Contains("keyword") using asp.net C# ?
I'm using stored procedures now, but linq to sql or entity framework are also a possibility.
If you want better performance then you could look into a full text search. Note that this is currently not supported by LINQ to SQL but you can write the SQL in a stored procedure and call the stored procedure from your application. The accepted answer for this StackOverflow post recommends reading this article.
Well you could achieve this from the db side using a LIKE
LIKE (Transact-SQL)
Something like
DECLARE #Table TABLE(
Val VARCHAR(50)
)
INSERT INTO #Table SELECT 'asdf'
INSERT INTO #Table SELECT 'tada'
INSERT INTO #Table SELECT 'foo'
INSERT INTO #Table SELECT 'bar'
INSERT INTO #Table SELECT 'test'
INSERT INTO #Table SELECT 'test foo'
DECLARE #Lookup VARCHAR(50)
SELECT #Lookup = 'foo'
SELECT *
FROM #Table
WHERE Val LIKE '%' + #Lookup + '%'
You should never fetch more data from your database than you need. So it is best for you to restrict your rows inside the data layer (ie. your stored procedure). You can do this by only returning matching rows:
SELECT * FROM Products WHERE ProductName LIKE '%' + #keyword + '%'
Where #keyword is a parameter to your store procedure.
But be aware that performance using LIKE can be slow, since it must read the entire table. You can better performance more by matching products that starts with the keyword:
SELECT * FROM Products WHERE ProductName LIKE #keyword + '%'
Note I removed the '%' before #keyword. This enables SQL Server to use an index on the ProductName column to find the rows much quicker!
Fore further help, please post your stored procedure...
Might be overkill but check out lucene.net, I believe it is what stack overflow uses for its searching