I have a table DEPT, which holds 2 columns - ID, NAME.
A search form is presented with the IDs from the DEPT table and the user can chose any number of IDs and submit the form, to get the related NAMEs.
Clarification/Inputs:
I don't want to build a dynamic query - its not manageable.
I prefer a stored procedure using table-valued parameters
Any other solutions to proceed?
NOTE:
This example is simple with 1 table - in real life, I have to deal with more than 6 tables!
Thanks for any suggestions
CREATE TYPE dbo.DeptList
AS TABLE
(
ID INT
);
GO
CREATE PROCEDURE dbo.RetrieveDepartments
#dept_list AS dbo.DeptList READONLY
AS
BEGIN
SET NOCOUNT ON;
SELECT Name FROM dbo.table1 WHERE ID IN (SELECT ID FROM #dept)
UNION ALL
SELECT Name FROM dbo.table2 WHERE ID IN (SELECT ID FROM #dept)
-- ...
END
GO
Now in your C# code, create a DataTable, fill it in with the IDs, and pass it in to the stored procedure. Assuming you already have a list called tempList and the IDs are stored in id:
DataTable tvp = new DataTable();
tvp.Columns.Add(new DataColumn("ID"));
foreach(var item in tempList)
{
tvp.Rows.Add(item.id);
}
using (connObject)
{
SqlCommand cmd = new SqlCommand("StoredProcedure", connObject);
cmd.CommandType = CommandType.StoredProcedure;
SqlParameter tvparam = cmd.Parameters.AddWithValue("#dept_list", tvp);
tvparam.SqlDbType = SqlDbType.Structured;
...
}
You can also use a split function. Many exist, this is the one I like if you can guarantee that the input is safe (no <, >, & etc.):
CREATE FUNCTION dbo.SplitInts_XML
(
#List VARCHAR(MAX),
#Delimiter CHAR(1)
)
RETURNS TABLE
AS
RETURN
(
SELECT Item = y.i.value('(./text())[1]', 'int')
FROM
(
SELECT x = CONVERT(XML, '<i>'
+ REPLACE(#List, #Delimiter, '</i><i>') + '</i>').query('.')
) AS a
CROSS APPLY x.nodes('i') AS y(i)
);
GO
Now your procedure can be:
CREATE PROCEDURE dbo.RetrieveDepartments
#dept_list VARCHAR(MAX)
AS
BEGIN
SET NOCOUNT ON;
;WITH d AS (SELECT ID = Item FROM dbo.SplitInts(#dept_list, ','))
SELECT Name FROM dbo.table1 WHERE ID IN (SELECT ID FROM d)
UNION ALL
SELECT Name FROM dbo.table2 WHERE ID IN (SELECT ID FROM d)
-- ...
END
GO
Related
I have a SQL query that is being used in a C# controller class to return search query results:
SELECT #Output = (SELECT Name, Id
FROM [dbo].[Users]
WHERE Name = 'Robert');
However, when I run this query, I get the following error:
Only one expression can be specified in the select list when the subquery is not introduced with EXISTS.
I know that simply removing one of the column names will fix the issue, but I want to be able to return the Name and ID for each searched user.
Is there a way to change my query so that I can return the desired columns and still keep my #Output parameter in the query? Any recommendations would be much appreciated
One method is to concatenate them:
SELECT #Output = (SELECT Name + '|' + CONVERT(VARCHAR(255), Id)
FROM [dbo].[Users]
WHERE Name = 'Robert'
);
Another alternative is to use two variables, because you want two items:
SELECT #Name = Name, #Id = Id
FROM [dbo].[Users]
WHERE Name = 'Robert';
Given that you know that the name is 'Robert', I don't see why that is useful. You can do:
DECLARE #Name VARCHAR(255);
SET #Name = 'Robert';
SELECT #Id = Id
FROM [dbo].[Users]
WHERE Name = #Name;
Not sure if this is what you were looking for, you can declare #output as table, and insert the values when condition is true.
Declare #output table ([name] varchar(50), ID int)
insert into #output([name], id) select 'abc', 1
select * from #output
Output: This is just sample data
name ID
abc 1
I am passing ids list as a varchar(500) and based upon that ids records are required.My sql code is
declare #Ids varchar(500) = '12964,12965,12966'
select *
from tblBooks
where BookID in (#Ids)
where BookID is varchar(50).Number of Ids can be 100.Converting #Ids into int gives following error
Conversion failed when converting the varchar value
'12964,12965,12966' to data type int
How do i find result as #Id are not converted into Int.
Use a table variable:
DECLARE #Ids TABLE (ID INT);
INSERT #Ids VALUES (12964),(12965),(12966);
SELECT *
FROM tblBooks
WHERE BookID in (SELECT ID FROM #Ids);
If you need to pass this to a procedure then you can use a table valued parameter:
CREATE TYPE dbo.ListOfInt AS TABLE (ID INT);
GO
CREATE PROCEDURE dbo.GetBooks #IDs dbo.ListOfInt READONLY
AS
BEGIN
SELECT *
FROM tblBooks
WHERE BookID in (SELECT ID FROM #Ids);
END
GO
DECLARE #IDs dbo.ListofInt;
INSERT #Ids VALUES (12964),(12965),(12966);
EXECUTE dbo.GetBooks #Ids;
Or From c#
var table = new DataTable();
table.Columns.Add("ID", typeof(int));
// ADD YOUR LIST TO THE TABLE
using (var connection = new SqlConnection("Connection String"))
using (var command = new SqlCommand("dbo.GetBooks", connection))
{
command.CommandType = CommandType.StoredProcedure;
var param = new SqlParameter("#Ids", SqlDbType.Structured);
param.TypeName = "dbo.ListofInt";
param.Value = table;
command.Parameters.Add(table);
connection.Open();
using (var reader = command.ExecuteReader())
{
while (reader.Read())
{
// do something
}
}
}
Once the TYPE is in place, you don't even need to use a stored procedure. You can simply call a normal query:
using (var connection = new SqlConnection("Connection String"))
using (var command = new SqlCommand("SELECT * FROM tblBooks WHERE BookID IN (SELECT ID FROM #IDs)", connection))
{
var param = new SqlParameter("#Ids", SqlDbType.Structured);
param.TypeName = "dbo.ListofInt";
param.Value = table;
command.Parameters.Add(table);
connection.Open();
// ETC
}
Doing the split in c# using String.Split() and passing the list to SQL will be more efficient than any approach that does the split in SQL
You can write the query as this:
declare #Ids varchar(500) = '12964,12965,12966'
select *
from tblBooks
where ','+cast(BookID as varchar(500))+',' like '%,'+#Ids+',%';
But you don't want to do that because the performance is bad -- the query cannot use indexes.
Three other options. Use dynamic SQL and plug the list directly into the query. Or use a split function to split the string. Or use a table variable:
declare #ids table (id int);
insert into #ids(id)
select 12964 union all select 12965 union all select 12966;
select b.*
from tblBooks b
where b.BookId in (select id from #ids);
This won't work. SQL Server does not split strings for you implicitly and there is no built in string split function in SQL Server either.
If you are driving this via C# you can use Table value parameters. You can also pass your query through Dapper-Dot-Net which will automatically parameterize an "In" query.
If you really must do this in T-SQL, you can also use a string splitting logic here is a relatively concise one.
SELECT i.value('./text()[1]', 'int') [id] into #ids
FROM( values(CONVERT(xml,'<r>' + REPLACE(#Ids+left(##dbts,0),',','</r><r>') + '</r>')) ) a(_)
CROSS APPLY _.nodes('./r') x(i)
select *
from tblBooks a
join #ids i on i.id = a.bookId
Create this function:
CREATE FUNCTION [dbo].[SplitDelimiterString] (#StringWithDelimiter VARCHAR(8000), #Delimiter VARCHAR(8))
RETURNS #ItemTable TABLE (Item VARCHAR(8000))
AS
BEGIN
DECLARE #StartingPosition INT;
DECLARE #ItemInString VARCHAR(8000);
SELECT #StartingPosition = 1;
--Return if string is null or empty
IF LEN(#StringWithDelimiter) = 0 OR #StringWithDelimiter IS NULL RETURN;
WHILE #StartingPosition > 0
BEGIN
--Get starting index of delimiter .. If string
--doesn't contain any delimiter than it will returl 0
SET #StartingPosition = CHARINDEX(#Delimiter,#StringWithDelimiter);
--Get item from string
IF #StartingPosition > 0
SET #ItemInString = SUBSTRING(#StringWithDelimiter,0,#StartingPosition)
ELSE
SET #ItemInString = #StringWithDelimiter;
--If item isn't empty than add to return table
IF( LEN(#ItemInString) > 0)
INSERT INTO #ItemTable(Item) VALUES (#ItemInString);
--Remove inserted item from string
SET #StringWithDelimiter = SUBSTRING(#StringWithDelimiter,#StartingPosition +
LEN(#Delimiter),LEN(#StringWithDelimiter) - #StartingPosition)
--Break loop if string is empty
IF LEN(#StringWithDelimiter) = 0 BREAK;
END
RETURN
END
Then call it like this:
declare #Ids varchar(500) = '12964,12965,12966'
select *
from tblBooks
where BookID in (SELECT * FROM dbo.SplitDelimiterString(#ids,','))
one way is to cast int to varchar. many other ways....
select *
from tblBooks
where CAST(BookID as varchar(50)) in (#Ids)
related: Define variable to use with IN operator (T-SQL)
My table is
(id int,property varchar)
Suppose I want to insert {3, 'a, b, c'}. How can I do it in a stored procedure?
The table entry would be:
id property
3 a
3 b
3 c
Also when i want to update my id=3 row by {3, 'ab, b, bg, ht'} . What would be the stored procedure for this insert and update operation? My table entries should become
id property
3 ab
3 b
3 bg
3 ht
sample table:
create table yourtable (id int,property varchar(5))
Procedure for that table:
create procedure p_test
(
#id int,
#prolist varchar(2000)
) as
begin
;with x as
(
SELECT * FROM yourtable WHERE id = #ID
)
MERGE INTO
x t1
using
(SELECT #id id, ltrim(t.c.value('.', 'VARCHAR(2000)')) property
FROM (
SELECT x = CAST('<t>' +
REPLACE(#prolist, ',', '</t><t>') + '</t>' AS XML)
) a
CROSS APPLY x.nodes('/t') t(c)) t2 on t1.id = t2.id and t1.property = t2.property
when not matched then INSERT (id,property)
VALUES(t2.id, t2.property)
when matched
THEN UPDATE SET t1.id = t2.id
WHEN NOT MATCHED BY SOURCE THEN DELETE
;
end
Testing:
exec p_test 3, 'b,c'
select * from yourtable
exec p_test 3, 'a,b,c'
select * from yourtable
exec p_test 3, 'a,c'
select * from yourtable
exec p_test 4, 'g,h'
select * from yourtable
Result:
id property
3 b
3 c
id property
3 b
3 c
3 a
id property
3 c
3 a
id property
4 g
3 c
3 a
4 h
EDIT:
in order to update a new column use this table:
create table yourtable (id int,property varchar(5), is_active bit default 1)
Use this procedure:
alter procedure p_test
(
#id int,
#prolist varchar(2000)
) as
begin
;with x as
(
SELECT * FROM yourtable WHERE id = #ID
)
MERGE INTO
x t1
using
(SELECT #id id, ltrim(t.c.value('.', 'VARCHAR(2000)')) property
FROM (
SELECT x = CAST('<t>' +
REPLACE(#prolist, ',', '</t><t>') + '</t>' AS XML)
) a
CROSS APPLY x.nodes('/t') t(c)) t2 on t1.id = t2.id and t1.property = t2.property
when not matched then INSERT (id,property, is_active)
VALUES(t2.id, t2.property, 1)
when matched
THEN UPDATE SET t1.id = t2.id, is_active = 1
WHEN NOT MATCHED BY SOURCE THEN
UPDATE SET t1.is_active = 0
;
end
First one:
insert into <tableName>(id, property) values(3, 'a');
insert into <tableName>(id, property) values(3, 'b');
insert into <tableName>(id, property) values(3, 'c');
Second issue:
update <tableName> set property='ab' where property = 'a';
update <tableName> set property='bg' where property = 'c';
insert into <tableName>(id, property) values(3, 'ht');
And now, a question: are you sure this is what your problem needs? Usually, when we call a column id we want it to be an identifier, that is, unique for each row. This may be a little bit off topic, but just in case...
There should be an id/primary key which will be unique. Profide any unique field and update records on the base of that unique field. Or you can make property unique or pair of id and property unique.
If I understood well, you could do something similar to this:
Insert INTO #tempTable
SELECT 3, * FROM dbo.splitstring('a,b,c,d')
It's just a pseudocode and you should do it inside your stored procedure.
If this is the right approach you have to take a look at this: T-SQL split string
I need to turn this query into an update statement. I will have to update the values from fields. Everything is already in place but the update statement.
Here is the select version of the query:
SELECT i.GoLiveDate, i.FirstBonusRun, i.TechFName, i.TechLName, i.TechEmail, i.TechPhone, i.WebISPFName, i.WebISPLName,
i.WebISPEmail, i.WebISPPhone, i.FullFillFName, i.FullFillLName, i.FullFillEmail, i.FullFillPhone, d.FName,
d.LName, d.HomePhone, d.Email
FROM NC_Information i
INNER JOIN Distributor d
ON d.DistID = i.ClientID
WHERE clientID = #value
Is it possible to update two different tables from within the same query?
Here is the code I have so far:
public void Update (int ClientID)
{
using ( var conn = new SqlConnection( GeneralFunctions.GetConnectionString() ) )
using ( var cmd = conn.CreateCommand() )
{
conn.Open();
cmd.CommandText =
#"SELECT i.GoLiveDate, i.FirstBonusRun, i.TechFName, i.TechLName, i.TechEmail, i.TechPhone, i.WebISPFName, i.WebISPLName,
i.WebISPEmail, i.WebISPPhone, i.FullFillFName, i.FullFillLName, i.FullFillEmail, i.FullFillPhone, d.FName,
d.LName, d.HomePhone, d.Email
FROM NC_Information i
INNER JOIN Distributor d
ON d.DistID = i.ClientID
WHERE clientID = #value";
cmd.Parameters.AddWithValue( "#value", ClientID );
cmd.ExecuteNonQuery();
}
}
You can't update multiple tables in one statement, but you can use a transaction to make sure that the updates are contingent upon one another:
BEGIN TRANSACTION
UPDATE SomeTable
SET SomeColumn = 'Foo'
WHERE SomeID = 123
UPDATE AnotherTable
SET AnotherColumn = 'Bar'
WHERE AnotherID = 456
COMMIT
I think, you cannot directly do the update on two tables. But you can Optimize the query.
How?
OUTPUT keyword in Insert/Update/Delete Statement
The first Update Statement's Select Data(filtered data) can be reused using the below mentioned example.
CREATE TABLE #table1
(
id INT,
employee VARCHAR(32)
)
go
INSERT INTO #table1 VALUES
(1, 'name1')
,(2, 'name2')
,(3, 'name3')
,(4, 'name4');
GO
DECLARE #GuestTable TABLE
(
id INT,
employee VARCHAR(32)
);
update #table1
Set id = 33
OUTPUT inserted.* INTO #GuestTable
Where id = 3
The Data in the '#GuestTable' Table is filtered data and can be
reused.
select * from #GuestTable
drop table #table1
Alternatively, you can create a dataset with two datatables, and let the tableadaptermanager manage the updates.
I am working on a web application where there are many tables but two will suffice to illustrate my problem:
User
Order
Let us say that the User table has a primary key "UserID", which is a foreign key in the Order table called "CreatedBy_UserID".
Before deleting a User, I would like to check if the Order table has a record created by the soon-to-be deleted user.
I know that a SqlException occurs if I try to delete the user but let us say that I want to check beforehand that the Order table does not have any records created by this user? Is there any SQL code which I could run which will check all foreign keys of a table if that row is being referenced?
This for me is generally useful code as I could remove the option for deletion altogether if it can be detected that the user exists in these other tables.
I don't want a simple query (SELECT COUNT(*) FROM Order WHERE CreatedBy_UserID == #userID) because this will not work if I create another foreign key to the Order table. Instead I want something that will traverse all foreign keys.
Can this be done?
Below is code for an sp that I've used in the past to perform this task (please excuse the indenting):
create proc dbo.usp_ForeignKeyCheck(
#tableName varchar(100),
#columnName varchar(100),
#idValue int
) as begin
set nocount on
declare fksCursor cursor fast_forward for
select tc.table_name, ccu.column_name
from
information_schema.table_constraints tc join
information_schema.constraint_column_usage ccu on tc.constraint_name = ccu.constraint_name join
information_schema.referential_constraints rc on tc.constraint_name = rc.constraint_name join
information_schema.table_constraints tc2 on rc.unique_constraint_name = tc2.constraint_name join
information_schema.constraint_column_usage ccu2 on tc2.constraint_name = ccu2.constraint_name
where tc.constraint_type = 'Foreign Key' and tc2.table_name = #tableName and ccu2.column_name = #columnName
order by tc.table_name
declare
#fkTableName varchar(100),
#fkColumnName varchar(100),
#fkFound bit,
#params nvarchar(100),
#sql nvarchar(500)
open fksCursor
fetch next from fksCursor
into #fkTableName, #fkColumnName
set #fkFound = 0
set #params=N'#fkFound bit output'
while ##fetch_status = 0 and coalesce(#fkFound,0) <> 1 begin
select #sql = 'set #fkFound = (select top 1 1 from [' + #fkTableName + '] where [' + #fkColumnName + '] = ' + cast(#idValue as varchar(10)) + ')'
print #sql
exec sp_executesql #sql,#params,#fkFound output
fetch next from fksCursor
into #fkTableName, #fkColumnName
end
close fksCursor
deallocate fksCursor
select coalesce(#fkFound,0)
return 0
end
This will select a value of 1 if a row has any foreign key references.
The call you would need would be:
exec usp_ForeignKeyCheck('User','UserID',23)
There is no clean way to iterate through all FK columns where multiple exist. You'd have to build some dynamic SQL to query the system tables and test each in turn.
Personally, I wouldn't do this. I know what FKs I have: I'll test each in turn
...
IF EXISTS (SELECT * FROM Order WHERE CreatedBy_UserID == #userID)
RAISERROR ('User created Orders ', 16, 1)
IF EXISTS (SELECT * FROM Order WHERE PackedBy_UserID == #userID)
RAISERROR ('User packed Orders', 16, 1)
...
You wouldn't dynamically iterate through each property of some user object and generically test each one would you? You'd have code for each property
This code will give you a list of the foreign keys which are defined for a specifit table:
select distinct name from sys.objects
where object_id in ( select constraint_object_id from sys.foreign_key_columns as fk
where fk.Parent_object_id = (select object_id from sys.tables
where name = 'tablename') )
You can use transaction to check it.
I know it seems like stone ax, but it working fast and stable.
private bool TestUser(string connectionString, int userID)
{
var result = true;
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
var command = connection.CreateCommand();
var transaction = connection.BeginTransaction();
command.Connection = connection;
command.Transaction = transaction;
try
{
command.CommandText = "DELETE User WHERE UserID = " + userID.ToString();
command.ExecuteNonQuery();
transaction.Rollback();
}
catch
{
result = false;
}
}
return result;
}