Key points for ms sql server as professional DB Developer
Key points for ms sql server as professional DB Developer
1- Use IsNull to set default value of amount,date
e.g ISNULL(ReturnAgentInfo,0) AS agentinfo
2- Don’t use the + operator to concatenate the expressions
3- Avoid the risk of the divide by zero error
e.g
SELECT ProductName
, Price
, (Price / NULLIF(PriceTax,0)) * 100 AS [PriceTaxRatio]
FROM Products
3- Counting SQL NULL values
SELECT COUNT(ISNULL(ProductName,'')) AS 'Number Of Product' FROM Products
4- avoide conversion in where clause
