I am creating an front end to the AdventureWorks sample database.
I am trying to update a row in HumanResources.Department.
I am using a DataSet with Table Adapter for this table.
Inserting and updating a row causes issues :
public Department InserDepartment(Department department)
{
try
{
department.ModifiedDate = DateTime.Now;
Int32 id = departmentTableAdapter.Insert(department.Name, department.GroupName, department.ModifiedDate);
return new Department();
}
catch (Exception ex)
{
return new Department();
}
}
public Department UpdateDepratment(Department department)
{
try
{
HumanResourcesDataSet.DepartmentDataTable tblDepartments = departmentTableAdapter.GetDataByDepartmentId(department.DepartmentID);
HumanResourcesDataSet.DepartmentRow departmentRow = tblDepartments[0];
departmentRow.Name = department.Name;
department.GroupName = department.GroupName;
department.ModifiedDate = DateTime.Now;
departmentTableAdapter.Update(tblDepartments);
department = GetDepartment(department.DepartmentID);
return department;
}
catch (Exception ex)
{
// TBD
}
}
Following exception occures:
The fractional part of the provided time value overflows the scale of the corresponding SQL Server parameter or column. Increase bScale in DBPARAMBINDINFO or column scale to correct this error.
The issue is caused by following line in my update method:
department.ModifiedDate = DateTime.Now;
The data set accepts a DateTime class for this column, the database definition is a datetime, not null.
I have implemented datetime columns in other databases, and never had this issue.
What am I missing, that causes the issue?
Where should I search for solution to this issue?
So, i did not entirely found a cause and a proper solution for this issue. I added new stored procedure for an update on the table in question, which seems to solve some issues. The issue is somewhere in my data provider (System.Data.OleDb) and my SQL server.
The server is a SQL - Express. I imported the database from a .bak file.
In the stored procedure, i set ModifiedDate = CURRENT_TIMESTAMP, and pass the other values as param.
My assumption is, that my update interfered with folloving SQL script
[ModifiedDate] [datetime] NOT NULL CONSTRAINT [DF_Department_ModifiedDate] DEFAULT (GETDATE())
I don't really want to tinker wiht the structure of the database and change a default, since i don't understand the database that well so far.
I can't really ignore the column as well, since I can update only an entire row with my table adapter, which includes the date that is set in my DataRow instance.
I am running data.bat file with the following lines:
Rem Tis batch file will populate tables
cd\program files\Microsoft SQL Server\MSSQL
osql -U sa -P Password -d MyBusiness -i c:\data.sql
The contents of the data.sql file is:
insert Customers
(CustomerID, CompanyName, Phone)
Values('101','Southwinds','19126602729')
There are 8 more similar lines for adding records.
When I run this with start > run > cmd > c:\data.bat, I get this error message:
1>2>3>4>5>....<1 row affected>
Msg 8152, Level 16, State 4, Server SP1001, Line 1
string or binary data would be truncated.
<1 row affected>
<1 row affected>
<1 row affected>
<1 row affected>
<1 row affected>
<1 row affected>
Also, I am a newbie obviously, but what do Level #, and state # mean, and how do I look up error messages such as the one above: 8152?
From #gmmastros's answer
Whenever you see the message....
string or binary data would be truncated
Think to yourself... The field is NOT big enough to hold my data.
Check the table structure for the customers table. I think you'll find that the length of one or more fields is NOT big enough to hold the data you are trying to insert. For example, if the Phone field is a varchar(8) field, and you try to put 11 characters in to it, you will get this error.
I had this issue although data length was shorter than the field length.
It turned out that the problem was having another log table (for audit trail), filled by a trigger on the main table, where the column size also had to be changed.
In one of the INSERT statements you are attempting to insert a too long string into a string (varchar or nvarchar) column.
If it's not obvious which INSERT is the offender by a mere look at the script, you could count the <1 row affected> lines that occur before the error message. The obtained number plus one gives you the statement number. In your case it seems to be the second INSERT that produces the error.
Just want to contribute with additional information: I had the same issue and it was because of the field wasn't big enough for the incoming data and this thread helped me to solve it (the top answer clarifies it all).
BUT it is very important to know what are the possible reasons that may cause it.
In my case i was creating the table with a field like this:
Select '' as Period, * From Transactions Into #NewTable
Therefore the field "Period" had a length of Zero and causing the Insert operations to fail. I changed it to "XXXXXX" that is the length of the incoming data and it now worked properly (because field now had a lentgh of 6).
I hope this help anyone with same issue :)
Some of your data cannot fit into your database column (small). It is not easy to find what is wrong. If you use C# and Linq2Sql, you can list the field which would be truncated:
First create helper class:
public class SqlTruncationExceptionWithDetails : ArgumentOutOfRangeException
{
public SqlTruncationExceptionWithDetails(System.Data.SqlClient.SqlException inner, DataContext context)
: base(inner.Message + " " + GetSqlTruncationExceptionWithDetailsString(context))
{
}
/// <summary>
/// PArt of code from following link
/// http://stackoverflow.com/questions/3666954/string-or-binary-data-would-be-truncated-linq-exception-cant-find-which-fiel
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
static string GetSqlTruncationExceptionWithDetailsString(DataContext context)
{
StringBuilder sb = new StringBuilder();
foreach (object update in context.GetChangeSet().Updates)
{
FindLongStrings(update, sb);
}
foreach (object insert in context.GetChangeSet().Inserts)
{
FindLongStrings(insert, sb);
}
return sb.ToString();
}
public static void FindLongStrings(object testObject, StringBuilder sb)
{
foreach (var propInfo in testObject.GetType().GetProperties())
{
foreach (System.Data.Linq.Mapping.ColumnAttribute attribute in propInfo.GetCustomAttributes(typeof(System.Data.Linq.Mapping.ColumnAttribute), true))
{
if (attribute.DbType.ToLower().Contains("varchar"))
{
string dbType = attribute.DbType.ToLower();
int numberStartIndex = dbType.IndexOf("varchar(") + 8;
int numberEndIndex = dbType.IndexOf(")", numberStartIndex);
string lengthString = dbType.Substring(numberStartIndex, (numberEndIndex - numberStartIndex));
int maxLength = 0;
int.TryParse(lengthString, out maxLength);
string currentValue = (string)propInfo.GetValue(testObject, null);
if (!string.IsNullOrEmpty(currentValue) && maxLength != 0 && currentValue.Length > maxLength)
{
//string is too long
sb.AppendLine(testObject.GetType().Name + "." + propInfo.Name + " " + currentValue + " Max: " + maxLength);
}
}
}
}
}
}
Then prepare the wrapper for SubmitChanges:
public static class DataContextExtensions
{
public static void SubmitChangesWithDetailException(this DataContext dataContext)
{
//http://stackoverflow.com/questions/3666954/string-or-binary-data-would-be-truncated-linq-exception-cant-find-which-fiel
try
{
//this can failed on data truncation
dataContext.SubmitChanges();
}
catch (SqlException sqlException) //when (sqlException.Message == "String or binary data would be truncated.")
{
if (sqlException.Message == "String or binary data would be truncated.") //only for EN windows - if you are running different window language, invoke the sqlException.getMessage on thread with EN culture
throw new SqlTruncationExceptionWithDetails(sqlException, dataContext);
else
throw;
}
}
}
Prepare global exception handler and log truncation details:
protected void Application_Error(object sender, EventArgs e)
{
Exception ex = Server.GetLastError();
string message = ex.Message;
//TODO - log to file
}
Finally use the code:
Datamodel.SubmitChangesWithDetailException();
Another situation in which you can get this error is the following:
I had the same error and the reason was that in an INSERT statement that received data from an UNION, the order of the columns was different from the original table. If you change the order in #table3 to a, b, c, you will fix the error.
select a, b, c into #table1
from #table0
insert into #table1
select a, b, c from #table2
union
select a, c, b from #table3
on sql server you can use SET ANSI_WARNINGS OFF like this:
using (SqlConnection conn = new SqlConnection("Data Source=XRAYGOAT\\SQLEXPRESS;Initial Catalog='Healthy Care';Integrated Security=True"))
{
conn.Open();
using (var trans = conn.BeginTransaction())
{
try
{
using cmd = new SqlCommand("", conn, trans))
{
cmd.CommandText = "SET ANSI_WARNINGS OFF";
cmd.ExecuteNonQuery();
cmd.CommandText = "YOUR INSERT HERE";
cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
cmd.CommandText = "SET ANSI_WARNINGS ON";
cmd.ExecuteNonQuery();
trans.Commit();
}
}
catch (Exception)
{
trans.Rollback();
}
}
conn.Close();
}
I had the same issue. The length of my column was too short.
What you can do is either increase the length or shorten the text you want to put in the database.
Also had this problem occurring on the web application surface.
Eventually found out that the same error message comes from the SQL update statement in the specific table.
Finally then figured out that the column definition in the relating history table(s) did not map the original table column length of nvarchar types in some specific cases.
I had the same problem, even after increasing the size of the problematic columns in the table.
tl;dr: The length of the matching columns in corresponding Table Types may also need to be increased.
In my case, the error was coming from the Data Export service in Microsoft Dynamics CRM, which allows CRM data to be synced to an SQL Server DB or Azure SQL DB.
After a lengthy investigation, I concluded that the Data Export service must be using Table-Valued Parameters:
You can use table-valued parameters to send multiple rows of data to a Transact-SQL statement or a routine, such as a stored procedure or function, without creating a temporary table or many parameters.
As you can see in the documentation above, Table Types are used to create the data ingestion procedure:
CREATE TYPE LocationTableType AS TABLE (...);
CREATE PROCEDURE dbo.usp_InsertProductionLocation
#TVP LocationTableType READONLY
Unfortunately, there is no way to alter a Table Type, so it has to be dropped & recreated entirely. Since my table has over 300 fields (😱), I created a query to facilitate the creation of the corresponding Table Type based on the table's columns definition (just replace [table_name] with your table's name):
SELECT 'CREATE TYPE [table_name]Type AS TABLE (' + STRING_AGG(CAST(field AS VARCHAR(max)), ',' + CHAR(10)) + ');' AS create_type
FROM (
SELECT TOP 5000 COLUMN_NAME + ' ' + DATA_TYPE
+ IIF(CHARACTER_MAXIMUM_LENGTH IS NULL, '', CONCAT('(', IIF(CHARACTER_MAXIMUM_LENGTH = -1, 'max', CONCAT(CHARACTER_MAXIMUM_LENGTH,'')), ')'))
+ IIF(DATA_TYPE = 'decimal', CONCAT('(', NUMERIC_PRECISION, ',', NUMERIC_SCALE, ')'), '')
AS field
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = '[table_name]'
ORDER BY ORDINAL_POSITION) AS T;
After updating the Table Type, the Data Export service started functioning properly once again! :)
When I tried to execute my stored procedure I had the same problem because the size of the column that I need to add some data is shorter than the data I want to add.
You can increase the size of the column data type or reduce the length of your data.
A 2016/2017 update will show you the bad value and column.
A new trace flag will swap the old error for a new 2628 error and will print out the column and offending value. Traceflag 460 is available in the latest cumulative update for 2016 and 2017:
https://support.microsoft.com/en-sg/help/4468101/optional-replacement-for-string-or-binary-data-would-be-truncated
Just make sure that after you've installed the CU that you enable the trace flag, either globally/permanently on the server:
...or with DBCC TRACEON:
https://learn.microsoft.com/en-us/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql?view=sql-server-ver15
Another situation, in which this error may occur is in
SQL Server Management Studio. If you have "text" or "ntext" fields in your table,
no matter what kind of field you are updating (for example bit or integer).
Seems that the Studio does not load entire "ntext" fields and also updates ALL fields instead of the modified one.
To solve the problem, exclude "text" or "ntext" fields from the query in Management Studio
This Error Comes only When any of your field length is greater than the field length specified in sql server database table structure.
To overcome this issue you have to reduce the length of the field Value .
Or to increase the length of database table field .
If someone is encountering this error in a C# application, I have created a simple way of finding offending fields by:
Getting the column width of all the columns of a table where we're trying to make this insert/ update. (I'm getting this info directly from the database.)
Comparing the column widths to the width of the values we're trying to insert/ update.
Assumptions/ Limitations:
The column names of the table in the database match with the C# entity fields. For eg: If you have a column like this in database:
You need to have your Entity with the same column name:
public class SomeTable
{
// Other fields
public string SourceData { get; set; }
}
You're inserting/ updating 1 entity at a time. It'll be clearer in the demo code below. (If you're doing bulk inserts/ updates, you might want to either modify it or use some other solution.)
Step 1:
Get the column width of all the columns directly from the database:
// For this, I took help from Microsoft docs website:
// https://learn.microsoft.com/en-us/dotnet/api/system.data.sqlclient.sqlconnection.getschema?view=netframework-4.7.2#System_Data_SqlClient_SqlConnection_GetSchema_System_String_System_String___
private static Dictionary<string, int> GetColumnSizesOfTableFromDatabase(string tableName, string connectionString)
{
var columnSizes = new Dictionary<string, int>();
using (var connection = new SqlConnection(connectionString))
{
// Connect to the database then retrieve the schema information.
connection.Open();
// You can specify the Catalog, Schema, Table Name, Column Name to get the specified column(s).
// You can use four restrictions for Column, so you should create a 4 members array.
String[] columnRestrictions = new String[4];
// For the array, 0-member represents Catalog; 1-member represents Schema;
// 2-member represents Table Name; 3-member represents Column Name.
// Now we specify the Table_Name and Column_Name of the columns what we want to get schema information.
columnRestrictions[2] = tableName;
DataTable allColumnsSchemaTable = connection.GetSchema("Columns", columnRestrictions);
foreach (DataRow row in allColumnsSchemaTable.Rows)
{
var columnName = row.Field<string>("COLUMN_NAME");
//var dataType = row.Field<string>("DATA_TYPE");
var characterMaxLength = row.Field<int?>("CHARACTER_MAXIMUM_LENGTH");
// I'm only capturing columns whose Datatype is "varchar" or "char", i.e. their CHARACTER_MAXIMUM_LENGTH won't be null.
if(characterMaxLength != null)
{
columnSizes.Add(columnName, characterMaxLength.Value);
}
}
connection.Close();
}
return columnSizes;
}
Step 2:
Compare the column widths with the width of the values we're trying to insert/ update:
public static Dictionary<string, string> FindLongBinaryOrStringFields<T>(T entity, string connectionString)
{
var tableName = typeof(T).Name;
Dictionary<string, string> longFields = new Dictionary<string, string>();
var objectProperties = GetProperties(entity);
//var fieldNames = objectProperties.Select(p => p.Name).ToList();
var actualDatabaseColumnSizes = GetColumnSizesOfTableFromDatabase(tableName, connectionString);
foreach (var dbColumn in actualDatabaseColumnSizes)
{
var maxLengthOfThisColumn = dbColumn.Value;
var currentValueOfThisField = objectProperties.Where(f => f.Name == dbColumn.Key).First()?.GetValue(entity, null)?.ToString();
if (!string.IsNullOrEmpty(currentValueOfThisField) && currentValueOfThisField.Length > maxLengthOfThisColumn)
{
longFields.Add(dbColumn.Key, $"'{dbColumn.Key}' column cannot take the value of '{currentValueOfThisField}' because the max length it can take is {maxLengthOfThisColumn}.");
}
}
return longFields;
}
public static List<PropertyInfo> GetProperties<T>(T entity)
{
//The DeclaredOnly flag makes sure you only get properties of the object, not from the classes it derives from.
var properties = entity.GetType()
.GetProperties(System.Reflection.BindingFlags.Public
| System.Reflection.BindingFlags.Instance
| System.Reflection.BindingFlags.DeclaredOnly)
.ToList();
return properties;
}
Demo:
Let's say we're trying to insert someTableEntity of SomeTable class that is modeled in our app like so:
public class SomeTable
{
[Key]
public long TicketID { get; set; }
public string SourceData { get; set; }
}
And it's inside our SomeDbContext like so:
public class SomeDbContext : DbContext
{
public DbSet<SomeTable> SomeTables { get; set; }
}
This table in Db has SourceData field as varchar(16) like so:
Now we'll try to insert value that is longer than 16 characters into this field and capture this information:
public void SaveSomeTableEntity()
{
var connectionString = "server=SERVER_NAME;database=DB_NAME;User ID=SOME_ID;Password=SOME_PASSWORD;Connection Timeout=200";
using (var context = new SomeDbContext(connectionString))
{
var someTableEntity = new SomeTable()
{
SourceData = "Blah-Blah-Blah-Blah-Blah-Blah"
};
context.SomeTables.Add(someTableEntity);
try
{
context.SaveChanges();
}
catch (Exception ex)
{
if (ex.GetBaseException().Message == "String or binary data would be truncated.\r\nThe statement has been terminated.")
{
var badFieldsReport = "";
List<string> badFields = new List<string>();
// YOU GOT YOUR FIELDS RIGHT HERE:
var longFields = FindLongBinaryOrStringFields(someTableEntity, connectionString);
foreach (var longField in longFields)
{
badFields.Add(longField.Key);
badFieldsReport += longField.Value + "\n";
}
}
else
throw;
}
}
}
The badFieldsReport will have this value:
'SourceData' column cannot take the value of
'Blah-Blah-Blah-Blah-Blah-Blah' because the max length it can take is
16.
Kevin Pope's comment under the accepted answer was what I needed.
The problem, in my case, was that I had triggers defined on my table that would insert update/insert transactions into an audit table, but the audit table had a data type mismatch where a column with VARCHAR(MAX) in the original table was stored as VARCHAR(1) in the audit table, so my triggers were failing when I would insert anything greater than VARCHAR(1) in the original table column and I would get this error message.
I used a different tactic, fields that are allocated 8K in some places. Here only about 50/100 are used.
declare #NVPN_list as table
nvpn varchar(50)
,nvpn_revision varchar(5)
,nvpn_iteration INT
,mpn_lifecycle varchar(30)
,mfr varchar(100)
,mpn varchar(50)
,mpn_revision varchar(5)
,mpn_iteration INT
-- ...
) INSERT INTO #NVPN_LIST
SELECT left(nvpn ,50) as nvpn
,left(nvpn_revision ,10) as nvpn_revision
,nvpn_iteration
,left(mpn_lifecycle ,30)
,left(mfr ,100)
,left(mpn ,50)
,left(mpn_revision ,5)
,mpn_iteration
,left(mfr_order_num ,50)
FROM [DASHBOARD].[dbo].[mpnAttributes] (NOLOCK) mpna
I wanted speed, since I have 1M total records, and load 28K of them.
This error may be due to less field size than your entered data.
For e.g. if you have data type nvarchar(7) and if your value is 'aaaaddddf' then error is shown as:
string or binary data would be truncated
You simply can't beat SQL Server on this.
You can insert into a new table like this:
select foo, bar
into tmp_new_table_to_dispose_later
from my_table
and compare the table definition with the real table you want to insert the data into.
Sometime it's helpful sometimes it's not.
If you try inserting in the final/real table from that temporary table it may just work (due to data conversion working differently than SSMS for example).
Another alternative is to insert the data in chunks, instead of inserting everything immediately you insert with top 1000 and you repeat the process, till you find a chunk with an error. At least you have better visibility on what's not fitting into the table.
I am new to sql. I have added 2 new tables in database. The primary key of first is a foreign key in the other. The type of the keys is integer. Now I want to generate the keys in the code and assign it to new data so that the association between different rows of the tables is right. How do I ensure uniqueness of keys and also get the latest key from the db so that there are no errors while saving.
If I had used guids then I would have assigned a new guid to the primary key and then assigned the same to the foreign key in the other table. Also there are multiple clients and one server which is saving the data.
The data to be inserted in both the tables is decided in the c# code and is not derived from the row inserted in the primary table. Even if get the id in db then also the relation between the rows should be stored in some form from the code because after that it is lost.
The only viable way to do this is to use INT IDENTITY that the SQL Server database offers. Trust me on this one - you don't want to try to do this on your own!
Just use
CREATE TABLE dbo.YourTableOne(ID INT IDENTITY(1,1), ...other columns...)
and be done with it.
Once you insert a row into your first table, you can retrieve the value of the identity column like this:
-- do the insert into the first table
INSERT INTO dbo.YourTableOne(Col1, Col2, ...., ColN)
VALUES (Val1, Val2, ...., ValN)
DECLARE #NewID INT
-- get the newly inserted ID for future use
SELECT #NewID = SCOPE_IDENTITY()
-- insert into the second table, use first table's new ID for your FK column
INSERT INTO dbo.YourTableTwo (FKColumn, ......) VALUES(#NewID, ......)
Update: if you need to insert multiple rows into the first table and capture multiple generated ID values, use the OUTPUT clause:
-- declare a table variable to hold the data
DECLARE #InsertedData TABLE (NewID INT, ...some other columns as needed......)
-- do the insert into the first table
INSERT INTO dbo.YourTableOne(Col1, Col2, ...., ColN)
OUTPUT Inserted.ID, Inserted.Col1, ..., Inserted.ColN INTO #InsertedData(NewID, Col1, ..., ColN)
VALUES (Val1, Val2, ...., ValN)
and then go from there. You can get any values from the newly inserted rows into the temporary table variable, which will then allow you to decide which new ID values to use for which rows for your second table
As #marc_s said using Database managed keys is more viable. But in cases there is no much load on the database, for example because there are few users who work simultanously, I will use another easier method. That's I get the last id, I try to add new record, and if I encountered error for duplicate, I will try again. I limited this to 3 trials for my application and there's a 300 ms timeout between each trial. Dont forget that this approach has serious limitations. In my application, there are very few users, the work load is very low, and the connection is a local one so this will do job well. Perhaps in other applications you need to adjust the delay, and in some cases, the approach might completely fail. Here's the code,
I have two tables, Invoices and Invoices_Items the column which relates them is invoice_id:
byte attempts = 0;
tryagain: //Find last invoice no
OleDbCommand command = new OleDbCommand("SELECT MAX(invoice_id) FROM Invoices"
, myconnection);
int last_invoice_id = 0;
try
{
last_invoice_id = (int)command.ExecuteScalar();
}
catch (InvalidCastException) { };
// text_invoice_number.Text = Convert.ToString(last_invoice_id + 1);
try
{
command = new OleDbCommand(#"INSERT INTO Invoices
(invoice_id,patient_id,visit_id,issue_date,invoice_to,doctor_id,assistant_id)
VALUES(?,?,?,?,?,?,?)",myconnection);
// We use last_invoice_id+1 as primary key
command.Parameters.AddWithValue("#invoice_id",last_invoice_id+1);
// I will add other parameters here (with the exact order in query)
command.ExecuteNonQuery();
}
catch (Exception ex){
attempts++;
if (attempts <= 3) // 3 attempts
{
System.Threading.Thread.Sleep(300); // 300 ms second delay
goto tryagain;
}
else
{
MessageBox.Show("Can not add invoice to database, " + ex.Message, "Unexpected error!"
, MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
}
for (int i = 0; i <= listInvoiceItems.Count-1; i++)
{
command = new OleDbCommand(#"INSERT INTO Invoices_Items
(invoice_id,quantity,product,price,amount,item_type)
VALUES(?,?,?,?,?,?)",myconnection);
// Now we use our stored last_invoice_id+1 as foreign key
command.Parameters.AddWithValue("#invoice_id",last_invoice_id+1);
// Add other Invoice Items parameters here (with the exact order in query)
command.ExecuteNonQuery();
}
I have this method that has to scan a database table Announce continuously until a new record appears it compares it to a record from another table and if it matches it Deletes it from table announce and it continues to search until anothe record appears. Is there a better way of doing this instead of using a while(true) statement. Note: I am using Sqlserver
//Begin method
public void Begin()
{
string announce;
double announceID;
try
{
using (SqlConnection connStr = new SqlConnection(ConfigurationManager.ConnectionStrings["AnnounceConnString"].ConnectionString))
{
while (true)
{
//Selects Last record written to tblAnnounce
SqlCommand sqlcommandStart = new SqlCommand("AnnounceSelect", connStr);
sqlcommandStart.CommandType = CommandType.StoredProcedure;
connStr.Open();
SqlDataReader dr = sqlcommandStart.ExecuteReader();
if (dr.HasRows)
{
while (dr.Read())
{
announce = dr["AnnounceID"].ToString();
announceID = Convert.ToDouble(announce);
//Compares Values
//if it matches then DELETE record from TblAnnounce
}
connStr.Close();
}
else
{
connStr.Close();
}
dr.Close();
}
}
}
catch(Exception ex)
{
string exception = ex.Message;
MessageBox.Show(exception
}
}
Rather than check continuously for insert record you can easily handle this on insert. check before insert in other table and if exist you can ignore the insert.
Or you can use insert triger for this table in database level to handle the delete record if matching record found.
by C# code you can do this using CLR Triggers. check the sample at the end of MSDN page.
EDIT
AS per your new comments you are not inserting data, but you want to compare and delete records. you can do as below. change the sql query as you need
using (var sc = new SqlConnection(ConnectionString))
using (var cmd = sc.CreateCommand())
{
sc.Open();
cmd.CommandText = "delete from TableB where OtherID in (select distinct ID from tableA)";
cmd.ExecuteNonQuery();
}
What are you actually trying to do here? If you are accepting values into the announce and deleting them if they already exist then a trigger is fine. However, you can also write a query or view to just select the rows where there is or is not a matching row. Both these ways mean you don't actually have to constantly monitor the table at all.
Another way is to consider using a dependency
http://msdn.microsoft.com/en-us/library/62xk7953.aspx
alternatively, depending on your situation, a queue to get the message into your announce table might be a better model.
http://msdn.microsoft.com/en-us/library/ms345108(v=sql.90).aspx
instead of a constantly scanning process. You can do the logic as the new message arrives.
I think the dependency will be the most suited to you from what you've written so far.
// you can use inner join in delete statement in T-Sql :
DELETE FROM tbl1
FROM table1 AS tbl1
INNER JOIN table2 AS tbl2 ON tbl1.Id=tble2.Id
Design of SQL Table Users:
Columns:
ID(Primary Key),
Name,
Age,
Zip.
I am displaying a grid view onto the asp.net application with the above table details which i am able to do now.Right now i am displaying only Name,age,zip on to the gridview.There is a form below the gridview where user can enter the data and save back to the DB.Here i am able to enter name,age,zip to the database and i am able to see the changes in the gridview.
So when i enter a duplicate name its not saving to the database as expected,at this point i have to show some thing to the user that the name already exists .
Here is my code in c#:
try
{
param[0] = new SqlParameter("#Name", SqlDbType.NVarChar);
param[0].Value = txtName.Text;
param[1] = new SqlParameter("#Age", SqlDbType.NVarChar);
param[1].Value = txtAge.Text;
param[2] = new SqlParameter("#Zip", SqlDbType.int);
param[2].Value = txtZip.Text;
DBHelper helper = new DBHelper();
helper.ExecuteNonQuery(CommandType.StoredProcedure, "Add_Users", param);
GridView1.DataBind();
}
catch (Exception ex)
{
}
I am expecting an sql exception in the above code where i am planning to notify the user .But i am unable to get any exception .
Can some one suggest where i am missing the catch here.
I just want to notify the user that the name is already taken eventually.
Using exceptions is a bad design in this case. This is not an error, but a predictable behaviour of your program.
One of the easiest ways to solve the problem is doing a select at the end of the Add_Users stored procedure that returns 1 or 0, depending on the success or failure, and using ExecuteScalar insead of ExecuteNonQuery to get the result.
You can also use a return in the stored procedure, and take back that value (geenrally as a special output parameter), but I don't know if the DbHelper allows you to do so.
You might also want to post your SQL code for "Add_Users".
I would think about doing a validation step rather than attempting to add it. So have one Stored Procedure for validation were you check the number of rows that contain the name you are trying to add. If the count is zero then proceed with the add. If there are records with that name then display a message to the user.
In your DBHelper use count to determine if your db should commit or not :
int count = SELECT COUNT(column_name) FROM table_name
and return it to your method which can then test it (instead of using Try/Catch)
if (helper.ExecuteNonQuery(CommandType.StoredProcedure, "Add_Users", param) >0))
{
// Show Error
}else
{
// all ok
}