Tag Archives: T-SQL

Calculating Statistical Values in T-SQL: Mean (Average), Median, Mode and Range

Sometimes you may need to calculate statistical values based on a set of values you have in a table. Let’s start with explaining what these values represent, in case you don’t already know. For the purposes of this post, we … Read More »»»

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How To Flush PRINT Buffer in T-SQL, Or Output Messages In Real Time

When debugging SQL scripts, oftentimes the developer or DBA would want to see what is happening as the script executes. While it is possible to set up breakpoints in SSMS and step-into/-over code, sometimes all that one wants is to … Read More »»»

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Find a String Value in the Whole Database: Searching for Text in Tables and Columns

Once in a while you may come across a problem when you are not familiar with the database structure you are dealing with. You may have to deal with the front end only and values that are only presented to … Read More »»»

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The Equivalent of T-SQL’s SELECT TOP N in Oracle PL/SQL

So you have been coding away T-SQL queries for a while now and know that by using the TOP keyword you can select the first what’s-the-number rows of your result set. Suddenly you find yourself in a familiar SQL environment, … Read More »»»

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How to Calculate the Number of Seconds Since Last Epoch (1/1/1970) in T-SQL

In certain situations, you may need to calculate the number of seconds that have passed since the start of the epoch. In computer world, the start of the epoch most often refers to the Unix epoch, also known as Unix … Read More »»»

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Avoiding Deadlock Transaction Errors by Using ROWLOCK Hint in T-SQL

When updating a single row data in a table, it may take a nasty while if the table is big and you have a condition in a WHERE clause on a column that is not indexed. In this case SQL … Read More »»»

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How to Use NOLOCK and ISOLATION LEVEL to Optimize T-SQL Query Performace

In this article, we will discuss how a NOLOCK hint can help improve performance of queries. Suppose you have a table: CREATE TABLE Users ( UserId INT PRIMARY KEY IDENTITY(1, 1) NOT NULL, FirstName NVARCHAR(50) NOT NULL, LastName NVARCHAR(50) NOT … Read More »»»

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Saving Bulk Modified or Deleted SQL Database Data for Recovery

Sometimes you need to modify or remove data in bulk in a SQL database. Whatever the reason is, it is always a good practice to store such changes so that if something goes wrong you would be able to restore … Read More »»»

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Create a SQL CLR Stored Procedure Using .NET (C# Example)

T-SQL is limited in its functions and getting the results you need sometimes becomes very complex and the statements used consequently hard to decipher. With SQL Server 2005, Microsoft introduced CLR (Common Language Runtime) technology which allows you to use … Read More »»»

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What is CLR, How to Check If It is Enabled and How to Enable It

CLR stands for Common Language Runtime and is a technology developed by Microsoft that allows you to use managed .NET code in SQL Server environment. In other words, you can write your stored procedures, triggers and user-defined functions, aggregates and … Read More »»»

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