I am working on an MVC app with a database where I have a lot of empty columns in each table. Now if a user dynamically adds a field on form I have to check that which column is completely empty(available) and then assign it to the user added field.
For that matter I searched and found the following SQL code and it works fine.
declare #col varchar(255), #cmd varchar(max)
DECLARE getinfo cursor for
SELECT c.name as colum FROM sys.tables t JOIN sys.columns c ON t.Object_ID = c.Object_ID
WHERE t.Name = 'MyTableName'
OPEN getinfo
FETCH NEXT FROM getinfo into #col
WHILE ##FETCH_STATUS = 0
BEGIN
SELECT #cmd = 'IF NOT EXISTS (SELECT * FROM MyTableName WHERE [' + #col + '] IS NOT NULL) BEGIN print ''' + #col + ''' end'
EXEC(#cmd)
FETCH NEXT FROM getinfo into #col
END
CLOSE getinfo
DEALLOCATE getinfo
It prints all columns in the given table having all empty rows. Now I want to get that list in my MVC Controller. Since it is printing the results so I cannot use SqlDataReader. So I found a method in answers of this question. It gives me results one by one.
public ActionResult getList()
{
SqlConnection con = DBHelperADO.GetConnection();
SqlCommand cmd = new SqlCommand(query, con); // query = sql code mentioned above
con.Open();
using (con)
{
con.InfoMessage += connection_InfoMessage;
SqlDataReader dr = cmd.ExecuteReader();
}
}
void connection_InfoMessage(object sender, SqlInfoMessageEventArgs e)
{
var outputFromStoredProcedure = e.Message;
}
How to populate a List of all column names from the handler? (can't use session or static list)
I don't want to use Event Handler in MVC app so is there any better option? (may be any other SQL code to give me the required result or getting the PRINT output by some other method)
UPDATED according to #AwaisMahmood suggestion
You can change the print sentence by a temp table and then return it
(I don't have checked the correct sintax for the quotes in the set #cmd... line, but you can get the idea)
declare #col varchar(255), #cmd varchar(max)
DECLARE getinfo cursor for
SELECT c.name as colum FROM sys.tables t JOIN sys.columns c ON t.Object_ID = c.Object_ID
WHERE t.Name = 'MyTableName'
CREATE TABLE #EmptyFields {
FieldName nvarchar(60)
}
OPEN getinfo
FETCH NEXT FROM getinfo into #col
WHILE ##FETCH_STATUS = 0
BEGIN
SELECT #cmd = 'IF NOT EXISTS (SELECT * FROM MyTableName WHERE [' + #col + '] IS NOT NULL)
BEGIN
insert into #EmptyFields (FieldName) values (''' + #col +
'')
' end'
EXEC(#cmd)
FETCH NEXT FROM getinfo into #col
END
CLOSE getinfo
DEALLOCATE getinfo
select * from #EmptyTables
Then, in the client, you can use a datareader as usual to fill a List<string> or simmilar.
Related
I have created a query that generates a CSV file (it isn't working properly at the moment), but I need to update it every 15 minutes. I see this being done by either appending the data or deleting the CSV and then rewriting it with all relevant data. The data is from a table that is updated every 15 minutes from a stored procedure. The file name cannot change.
I have been reading that you cannot delete or append a CSV file using SQL, be that BCP or any other means.
Is the appropriate way to write a service in C# to do this or is there a way to do it in SQL. I am not convinced my query is correct either.
My query is:
DECLARE #_FilePath NVARCHAR(MAX)
DECLARE #_FileName NVARCHAR(MAX)
DECLARE #_SerialNumber NVARCHAR(MAX)
DECLARE #_OutputPath NVARCHAR(MAX)
CREATE TABLE #tmp
(
SerialNumber NVARCHAR(75),
CustomerName NVARCHAR(MAX),
Processed BIT,
FolderLocation NVARCHAR(MAX)
)
INSERT INTO #tmp
SELECT d.SerialNumber, d.CustomerName, 0, f.folderLocation
FROM Staging.Device d
INNER JOIN Staging.FtpFolders f ON d.CustomerName = f.CustomerName
WHILE (SELECT COUNT(*) FROM #tmp WHERE Processed = 0) > 0
BEGIN
SET #_SerialNumber = (SELECT TOP 1 SerialNumber FROM #tmp
WHERE Processed = 0 AND SerialNumber IS NOT NULL)
SELECT TOP 1 #_FilePath = FolderLocation
FROM #tmp
WHERE Processed = 0 AND SerialNumber = #_SerialNumber
SELECT #_FileName = CONVERT(DateTime, DATEDIFF(DAY, 0, GETDATE()))
SET #_OutputPath = #_FilePath + '\' + #_FileName + '.csv'
UPDATE #tmp
SET Processed = 1
WHERE SerialNumber = #_SerialNumber
SELECT #_OutputPath
DECLARE #ExportSQL NVARCHAR(MAX);
SET #ExportSQL = N'EXEC master.dbo.xp_cmdshell ''bcp "SELECT * FROM [Staging].[PivotedData15]" queryout "' + #_OutputPath + '" -T -c -t -S '''
END
DROP TABLE #tmp
I'm trying to write a stored procedure to search for a string in all tables of a SQL Server database. I was able to find a good stored procedure for this purpose
However I don't want to just put the #Tablenames manually, I want it to go to a table called Enums_Tables that has an ID, and use that ID as #Tablenames.
What I have being thinking to solve this:
I could write another stored procedure to select all Id's from Enums_Tables and execute the first stored procedure, like in here
I could also pass the parameter in C#, since I'm going to use it as a search textbox. But the ideal would be making a single stored procedure.
Could you please help me with this?
EDIT
Thanks to GPW I have been able to solve this problem. I also encountered problems with the collation, but I also solve it. Below is the final stored procedure.
USE [DynaForms]
GO
/****** Object: stored procedure [dbo].[SP_SearchTables] Script Date: 09/11/2017 14:59:15 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[SP_SearchTables]
--#Tablenames VARCHAR(500)
#SearchStr NVARCHAR(60)
,#GenerateSQLOnly Bit = 0
,#SchemaNames VARCHAR(500) ='%'
AS
/*
Parameters and usage
#Tablenames -- Provide a single table name or multiple table name with comma seperated.
If left blank , it will check for all the tables in the database
Provide wild card tables names with comma seperated
EX :'%tbl%,Dim%' -- This will search the table having names comtains "tbl" and starts with "Dim"
#SearchStr -- Provide the search string. Use the '%' to coin the search. Also can provide multiple search with comma seperated
EX : X%--- will give data staring with X
%X--- will give data ending with X
%X%--- will give data containig X
%X%,Y%--- will give data containig X or starting with Y
%X%,%,,% -- Use a double comma to search comma in the data
#GenerateSQLOnly -- Provide 1 if you only want to generate the SQL statements without seraching the database.
By default it is 0 and it will search.
##SchemaNames -- Provide a single Schema name or multiple Schema name with comma seperated.
If left blank , it will check for all the tables in the database
Provide wild card Schema names with comma seperated
EX :'%dbo%,Sales%' -- This will search the Schema having names comtains "dbo" and starts with "Sales"
Samples :
1. To search data in a table
EXEC SP_SearchTables #Tablenames = 'T1'
,#SearchStr = '%TEST%'
The above sample searches in table T1 with string containing TEST.
2. To search in a multiple table
EXEC SP_SearchTables #Tablenames = 'T2'
,#SearchStr = '%TEST%'
The above sample searches in tables T1 & T2 with string containing TEST.
3. To search in a all table
EXEC SP_SearchTables #Tablenames = '%'
,#SearchStr = '%TEST%'
The above sample searches in all table with string containing TEST.
4. Generate the SQL for the Select statements
EXEC SP_SearchTables #Tablenames = 'T1'
,#SearchStr = '%TEST%'
,#GenerateSQLOnly = 1
5. To Search in tables with specfic name
EXEC SP_SearchTables #Tablenames = '%T1%'
,#SearchStr = '%TEST%'
,#GenerateSQLOnly = 0
6. To Search in multiple tables with specfic names
EXEC SP_SearchTables #Tablenames = '%T1%,Dim%'
,#SearchStr = '%TEST%'
,#GenerateSQLOnly = 0
7. To specify multiple search strings
EXEC SP_SearchTables #Tablenames = '%T1%,Dim%'
,#SearchStr = '%TEST%,TEST1%,%TEST2'
,#GenerateSQLOnly = 0
8. To search comma itself in the tables use double comma ",,"
EXEC SP_SearchTables #Tablenames = '%T1%,Dim%'
,#SearchStr = '%,,%'
,#GenerateSQLOnly = 0
EXEC SP_SearchTables #Tablenames = '%T1%,Dim%'
,#SearchStr = '%with,,comma%'
,#GenerateSQLOnly = 0
9. To Search by SchemaName
EXEC SP_SearchTables #Tablenames = '%T1%,Dim%'
,#SearchStr = '%,,%'
,#GenerateSQLOnly = 0
,#SchemaNames = '%dbo%,Sales%'
*/
SET NOCOUNT ON
DECLARE #MatchFound BIT
SELECT #MatchFound = 0
DECLARE #CheckTableNames Table
(
Schemaname sysname
,Tablename sysname
)
DECLARE #SearchStringTbl TABLE
(
SearchString VARCHAR(500)
)
DECLARE #SQLTbl TABLE
(
Tablename SYSNAME
,WHEREClause VARCHAR(MAX)
,SQLStatement VARCHAR(MAX)
,Execstatus BIT
)
DECLARE #SQL VARCHAR(MAX)
DECLARE #TableParamSQL VARCHAR(MAX)
DECLARE #SchemaParamSQL VARCHAR(MAX)
DECLARE #TblSQL VARCHAR(MAX)
DECLARE #tmpTblname sysname
DECLARE #ErrMsg VARCHAR(100)
/*
IF LTRIM(RTRIM(#Tablenames)) IN ('' ,'%')
BEGIN
INSERT INTO #CheckTableNames
SELECT Name
FROM sys.tables
END
ELSE
BEGIN
IF CHARINDEX(',',#Tablenames) > 0
SELECT #SQL = 'SELECT ''' + REPLACE(#Tablenames,',','''as TblName UNION SELECT ''') + ''''
ELSE
SELECT #SQL = 'SELECT ''' + #Tablenames + ''' as TblName '
SELECT #TblSQL = 'SELECT T.NAME
FROM SYS.TABLES T
JOIN (' + #SQL + ') tblsrc
ON T.name LIKE tblsrc.tblname '
INSERT INTO #CheckTableNames
EXEC(#TblSQL)
END
*/
--IF LTRIM(RTRIM(#Tablenames)) = ''
--BEGIN
-- SELECT #Tablenames = '%'
--END
IF LTRIM(RTRIM(#SchemaNames)) =''
BEGIN
SELECT #SchemaNames = '%'
END
--IF CHARINDEX(',',#Tablenames) > 0
-- SELECT #TableParamSQL = 'SELECT ''' + REPLACE(#Tablenames,',','''as TblName UNION SELECT ''') + ''''
--ELSE
-- SELECT #TableParamSQL = 'SELECT ''' + #Tablenames + ''' as TblName '
IF CHARINDEX(',',#SchemaNames) > 0
SELECT #SchemaParamSQL = 'SELECT ''' + REPLACE(#SchemaNames,',','''as SchemaName UNION SELECT ''') + ''''
ELSE
SELECT #SchemaParamSQL = 'SELECT ''' + #SchemaNames + ''' as SchemaName '
SELECT #TblSQL = 'SELECT SCh.NAME,T.NAME
FROM SYS.TABLES T
JOIN SYS.SCHEMAS SCh
ON SCh.SCHEMA_ID = T.SCHEMA_ID
INNER JOIN [DynaForms].[dbo].[Enums_Tables] et on
(et.Id = T.NAME COLLATE Latin1_General_CI_AS)'
INSERT INTO #CheckTableNames
(Schemaname,Tablename)
EXEC(#TblSQL)
IF NOT EXISTS(SELECT 1 FROM #CheckTableNames)
BEGIN
SELECT #ErrMsg = 'No tables are found in this database ' + DB_NAME() + ' for the specified filter'
PRINT #ErrMsg
RETURN
END
IF LTRIM(RTRIM(#SearchStr)) =''
BEGIN
SELECT #ErrMsg = 'Please specify the search string in #SearchStr Parameter'
PRINT #ErrMsg
RETURN
END
ELSE
BEGIN
SELECT #SearchStr = REPLACE(#SearchStr,',,,',',#DOUBLECOMMA#')
SELECT #SearchStr = REPLACE(#SearchStr,',,','#DOUBLECOMMA#')
SELECT #SearchStr = REPLACE(#SearchStr,'''','''''')
SELECT #SQL = 'SELECT ''' + REPLACE(#SearchStr,',','''as SearchString UNION SELECT ''') + ''''
INSERT INTO #SearchStringTbl
(SearchString)
EXEC(#SQL)
UPDATE #SearchStringTbl
SET SearchString = REPLACE(SearchString ,'#DOUBLECOMMA#',',')
END
INSERT INTO #SQLTbl
( Tablename,WHEREClause)
SELECT QUOTENAME(SCh.name) + '.' + QUOTENAME(ST.NAME),
(
SELECT '[' + SC.Name + ']' + ' LIKE ''' + REPLACE(SearchSTR.SearchString,'''','''''') + ''' OR ' + CHAR(10)
FROM SYS.columns SC
JOIN SYS.types STy
ON STy.system_type_id = SC.system_type_id
AND STy.user_type_id =SC.user_type_id
CROSS JOIN #SearchStringTbl SearchSTR
WHERE STY.name in ('varchar','char','nvarchar','nchar','text')
AND SC.object_id = ST.object_id
ORDER BY SC.name
FOR XML PATH('')
)
FROM SYS.tables ST
JOIN #CheckTableNames chktbls
ON chktbls.Tablename = ST.name
JOIN SYS.schemas SCh
ON ST.schema_id = SCh.schema_id
AND Sch.name = chktbls.Schemaname
WHERE ST.name <> 'SearchTMP'
GROUP BY ST.object_id, QUOTENAME(SCh.name) + '.' + QUOTENAME(ST.NAME) ;
UPDATE #SQLTbl
SET SQLStatement = 'SELECT * INTO SearchTMP FROM ' + Tablename + ' WHERE ' + substring(WHEREClause,1,len(WHEREClause)-5)
DELETE FROM #SQLTbl
WHERE WHEREClause IS NULL
WHILE EXISTS (SELECT 1 FROM #SQLTbl WHERE ISNULL(Execstatus ,0) = 0)
BEGIN
SELECT TOP 1 #tmpTblname = Tablename , #SQL = SQLStatement
FROM #SQLTbl
WHERE ISNULL(Execstatus ,0) = 0
IF #GenerateSQLOnly = 0
BEGIN
IF OBJECT_ID('SearchTMP','U') IS NOT NULL
DROP TABLE SearchTMP
EXEC (#SQL)
IF EXISTS(SELECT 1 FROM SearchTMP)
BEGIN
SELECT Tablename=#tmpTblname,* FROM SearchTMP
SELECT #MatchFound = 1
END
END
ELSE
BEGIN
PRINT REPLICATE('-',100)
PRINT #tmpTblname
PRINT REPLICATE('-',100)
PRINT replace(#SQL,'INTO SearchTMP','')
END
UPDATE #SQLTbl
SET Execstatus = 1
WHERE Tablename = #tmpTblname
END
IF #MatchFound = 0
BEGIN
SELECT #ErrMsg = 'No Matches are found in this database ' + DB_NAME() + ' for the specified filter'
PRINT #ErrMsg
RETURN
END
SET NOCOUNT OFF
Sorry in advance with the weird formatting, I can't put it more readable. I hope it helps someone. I also want to give credit to the onwer of the original stored procedure in here.
That stored procedure you linked to already has logic to check the table names in the database and populates a table variable with a list of tables to check. Just change this logic to Select from your ENUM_TABLES table instead. This could be based on an input parameter of #Id if you like...
In simple terms:
Remove the parameter #TableNames from the stored procedure
(optionally) replace the parameter with #ENUM_TABLE_ID or something
Change code in SP that looks like this:
IF LTRIM(RTRIM(#Tablenames)) = ''
/* Removed a load of lines looking at #TableNames...... */
....
SELECT #TblSQL = 'SELECT SCh.NAME,T.NAME
FROM SYS.TABLES T
JOIN SYS.SCHEMAS SCh
ON SCh.SCHEMA_ID = T.SCHEMA_ID
JOIN (' + #TableParamSQL + ') tblsrc
ON T.name LIKE tblsrc.tblname
JOIN (' + #SchemaParamSQL + ') schemasrc
ON SCh.name LIKE schemasrc.SchemaName
With something more like this:
SELECT #TblSQL = 'SELECT SCh.NAME,T.NAME
FROM SYS.TABLES T
JOIN SYS.SCHEMAS SCh
ON SCh.SCHEMA_ID = T.SCHEMA_ID
INNER JOIN ENUM_TABLES et on
(et.TABLENAME=T.NAME)
and (et.Id='+#ENUM_TABLE_ID+')'
And then I think it'll do what you want (lookup the list of tables from another table, based on an ID passed into the stored procedure)
(apologies for the slightly weird formatting of the SQL above; for some reason the SO markdown processor really didn't like that stuff, but it is hopefully readable. If anyone wants to try to edit this to improve it, be my guest.)
I'm passing a string variable to an IN Clause in sql (Stored Procedure). When declaring and setting the variable in sql I get back all the data that is required. But when setting the variable from c# I'm only receiving data based on the first status within that paramater.
I've got a function to split the statuses in the paramater list to retrieve the records:
ALTER FUNCTION [dbo].[fnSplit](
#sInputList VARCHAR(8000)
, #sDelimiter VARCHAR(10) = ';'
) RETURNS #List TABLE (item VARCHAR(8000))
BEGIN
DECLARE #sItem VARCHAR(8000)
WHILE CHARINDEX(#sDelimiter,#sInputList,0) <> 0
BEGIN
SELECT
#sItem=RTRIM(LTRIM(SUBSTRING(#sInputList,1,CHARINDEX(#sDelimiter,#sInputList,0)-1))),
#sInputList=RTRIM(LTRIM(SUBSTRING(#sInputList,CHARINDEX(#sDelimiter,#sInputList,0)+LEN(#sDelimiter),LEN(#sInputList))))
IF LEN(#sItem) > 0
INSERT INTO #List SELECT #sItem
END
IF LEN(#sInputList) > 0
INSERT INTO #List SELECT #sInputList
RETURN
END
My stored procedure is built like this:
ALTER procedure [dbo].[Get_RequestsAtEachStage]
(#managerRef int,
#status varchar(20))
as
BEGIN
WITH MaxStatusDate
as
(
select rs.requestID,rs.status from (
SELECT requestID,MAX([DateCreated]) AS MaxDate
FROM [LoanRequest].[dbo].[requestStatus]
GROUP BY RequestID) maxg
inner join [LoanRequest].[dbo].[requestStatus] rs on maxg.requestid = rs.requestid and maxg.MaxDate = rs.DateCreated
)
SELECT lr.ID, lr.serialNo, lr.model, lr.clientName, lr.address, lr.telephone, lr.contactName,
lr.swop, lr.substitueOfGoods, lr.printFunction, lr.copyFunction, lr.scanFunction,
lr.faxFunction, lr.controller, lr.controllerEmailAddress,
ml.Name, wl.Location, rt.requestType AS RequestTypeName, rs.status
FROM [dbo].[loanRequest] lr
INNER JOIN [dbo].[managersList] ml ON lr.managerRef = ml.ID
INNER JOIN [dbo].[warehouseList] wl ON lr.warehouseID = wl.ID
INNER JOIN [dbo].[requestType] rt ON lr.requestType = rt.ID
INNER JOIN MaxStatusDate rs ON lr.ID = rs.requestID
WHERE (#managerRef is null or lr.managerRef = #managerRef) AND rs.status IN (SELECT item FROM [dbo].[fnSplit](#status, ';'))
END
Based on the page the user access it will send through the appropriate statusses and retrieve the necessary records.
Setting the paramaters in sql as follows works perfect, I retrieve all the records:
DECLARE #managerRef INT
DECLARE #status NVARCHAR(100)
SET #managerRef = NULL
SET #status = 'Allocated;Readings Updated'
But, when I send it through c# within a string, it only retrieves records with the status of Allocated.:
string status = "Allocated;Readings Updated";
DataTable dtDevices = d.PopulateDevicesApproval(managerRef, status);
My method to retrieve the data from sql:
string filterstring = "";
filterstring = "Get_RequestsAtEachStage ";
cn = new SqlConnection(GetConnectionString());
SqlCommand myCmd = new SqlCommand(filterstring, cn);
myCmd.CommandType = CommandType.StoredProcedure;
cn.Open();
myCmd.Parameters.AddWithValue("#managerRef", managerRef);
myCmd.Parameters.AddWithValue("#status", status);
DataTable dt = new DataTable();
dt.Load(myCmd.ExecuteReader());
return dt;
Is there anything I am doing wrong?
--------- EDIT -----------
Running SELECT item FROM [dbo].fnSplit results from both c# and sql
Returning results from c#:
And returning results from sql:
I have a DB with 60 tables. In some of those tables I have a bit column named "Open" where I store a 0 if the record is not in use by an user (user access DB from a C# application) and an 1 if the record is in use.
Well, I need to get all the records from all the tables in my database where the "open" column value is true, or 1.
Is this even possible to do?
Here's a simple use of the undocumented sp_MSforeachtable:
EXEC sp_MSforeachtable
#command1='SELECT * FROM ? WHERE Open=1',
#whereand='AND o.id in (select object_id from sys.columns c where c.name=''Open'')'
Quick piece of code that gets list of tables within your database. Using a cursor loop through the answers checking it they have the fld named [open] and if it does the build a SQL statement and the execute this SQL string.
CREATE PROCEDURE usp_BulkTableOpenReport
AS
BEGIN
DECLARE #TBLS AS TABLE (REF INT IDENTITY (0,1), TABLENAME NVARCHAR(100), TABLEID BIGINT);
DECLARE #TBL AS NVARCHAR(100);
DECLARE #TBLID AS BIGINT;
DECLARE #SQL AS NVARCHAR(MAX);
DECLARE #I INT = 0;
DECLARE #M INT = 0;
DECLARE #V INT = 0
INSERT INTO #TBLS(TABLENAME,TABLEID)
SELECT NAME,OBJECT_ID FROM sys.tables
SELECT #M = MAX(REF) FROM #TBLS
WHILE #I <= #M
BEGIN
SELECT #TBL = TABLENAME, #TBLID= TABLEID FROM #TBLS WHERE REF = #I
/* CHECK TO MAKE INSURE THAT A FLD CALLED [OPEN] EXIST. */
SELECT #V = COUNT(*) FROM SYS.columns WHERE name = 'OPEN' AND OBJECT_ID = #TBLID
IF #V != 0
BEGIN
SET #SQL = 'SELECT * FROM [' + #TBL + '] WHERE [OPEN] = 1'
EXEC SP_EXECUTESQL #SQL
END;
SET #I = #I + 1
END;
END
GO
From your c# application exec the query "EXEC usp_BulkTableOpenReport" then loop through the table outputs.
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;
}