ChrisM@Work (7/23/2013)
-- why cast [Phone no] AS VARCHAR(MAX)?
-- why use CHARINDEX? You don't need the character position, you only need to know if
-- one string exists inside the other.
SELECT [customer].[Customer name],[customer].[Sl_No],[customer].[Id]
FROM [company].dbo.[customer]
WHERE ( Charindex('9000413237',CAST([company].dbo.[customer].[Phone no] AS VARCHAR(MAX)))>0 )
-- use this instead
SELECT c.[Customer name],c.[Sl_No],c.[Id]
FROM [company].dbo.[customer] c
WHERE c.[Phone no] LIKE '%9000413237%'
-- then try this, which is SARGable (can use a suitable index)
SELECT c.[Customer name],c.[Sl_No],c.[Id]
FROM [company].dbo.[customer] c
WHERE c.[Phone no] LIKE '9000413237%'
You have mentioned that using LIKE '9000413237%' is SARGable .There are many articles stating 'abc%' will use index but '%abc%' not.But using LIKE '%9000413237%' also helped me a lot.
Please see my thread regarding this here