What to do if MySQL update query returns 0 rows affected?
Try select count (*) from phonecalls where PhoneNumber = “999 29-4655”; That will give you the number of matching rows. If the result is 0, then there isn’t a row in the database that matches.- Check to make sure this returns some result. If it doesn’t return any result than the filter WHERE PhoneNumber = ‘999 29-4655’ is not correct.
How to query the database without observing changes?
If you want to query the database without observing changes, you can use Maybe or Single . If a Single query returns null , Room will throw EmptyResultSetException . UPDATE or DELETE queries can return void or int. If it is an int , the value is the number of rows affected by this query.
How to know if rows are affected by SQL update?
The rows with value ‘999’ have the correct number in a different column ( FaultCode of type varchar (50) ). I want to copy the values from FaultCode to PrecinctCode when PrecinctCode = 999. A message appears saying “3031 rows affected” but the affected rows still show 999 in the PrecinctCode column.
What happens if the query returns a nullable?
Since Reactive Streams does not allow null, if the query returns a nullable type, it will not dispatch anything if the value is null (like fetching an Entity row that does not exist). You can return Flowable or Flowable > to workaround this limitation.
How to return the number of rows affected by a query?
You can use SET NOCOUNT OFF to return the number of rows affected by your query. This will be another recordset at the client side. Some guidelines for posting questions… Bank of America Merchant…
When to use @ @ rowcount in SQL Server?
If this is SQL Server, try @@ROWCOUNT. If you get 0, you got 0. 🙂 You can use @@ROWCOUNT. For e.g. SELECT QBalance FROM dbo.CustomerBalance WHERE (CustomerID = 1) AND (MarchentID = @MerchantId) –This will return no of rows returned by above statement.
How to check if a SQL SELECT statement returns no rows?
To find out whether no matching rows exist you can use NOT EXISTS. Which can be more efficient than counting all matching rows IF NOT EXISTS (SELECT * FROM …) BEGIN PRINT ‘No matching row exists’ END If this is SQL Server, try @@ROWCOUNT. If you get 0, you got 0.