Transact-sql

Avoid prefixing your Stored Procedure names with sp_. SQL Server first checks in the master database even when the Schema name is provided.

Avoid using NOT IN whilst comparing nullable columns. Use NOT EXISTS instead. When NOT IN is used in a query, SQL Server compares each result to null (even if no

It is best to avoid using the * operator in your queries, use explicit column names instead. SQL Server scans through all column names and replaces the * operator with

In order to improve your queries’ performance, you should always include the owner or schema name of an object by including its prefix before an object. Otherwise, the SQL Server

The SQL Server query optimizer processes a JOIN?in the same order as the tables appear in the FROM?clause, when FORCEPLAN?is ON. SET FORCEPLAN ON | OFF

There are a number of math functions in T-SQL. Here are a few of them: SELECT SQRT(49) –Gives 7, Square RootSELECT PI() –Gives 3.14 …. PISELECT ROUND(15.30, 0) –Gives 15.

NUMERIC_ROUNDABORT?specifies the level of error reporting that has been generated when an expression being rounded has caused loss of precision. SET NUMERIC_ROUNDABORT ON

You can use the IIF statement to check quickly for conditions. For example: DECLARE @Spy varchar(20) = ’07’ SELECT IIF(@Spy = ‘007’, ‘Bond, James Bond’, ‘Ernst Stavro Blofeld’) If the

Sometimes you will need to disable an index, albeit temporarily. In order to disable an Index, make use of the following T-SQL Query: USE DatabaseNameGO ALTER INDEX NameOfIndex ON Table.Field