Stories of daily programming
Did you ever need to apply an aggregate function to fields values in a row? It happened to me just few days ago… I will try to explain better what I mean… Suppose you have a Sql Server table created with the following script: CREATE TABLE ROW_AGGREGATE_EXAMPLE ( ID INT IDENTITY(1, 1) PRIMARY KEY CLUSTERED,…
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It’s been a while since we last heard… The Dummy Programmer was really really busy and couldn’t write any post. But now I’m back to talk about a problem I came across. One of my applications in the production environment seemed to be stuck doing a series of database queries. My suspicion is that some other…
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Hi everyone! Today I want to talk about a performance problem I had a few days ago using a SQL Server cursor. Imagine using a cursor in the following classic way: DECLARE @ID INT DECLARE @ITEM_CODE VARCHAR(50) DECLARE MY_CURSOR CURSOR FOR SELECT ID, ITEM_CODE FROM MY_TABLE T LEFT JOIN A_TABLE T1 ON T.ID = T1.ID LEFT…
Delete all rows from all tables in a Sql Server database may not be an easy task. This because in a relational database you have foreign keys between tables, and to empty all tables you have to write delete statements in the correct order to avoid foreign key violations. I know that there are scripts…
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If you want to search a string in stored procedures, functions and views, maybe you can use some special tools. But, for instance, suppose that you can only use SQL Server Management Studio. Is there a way to do this? Yes…. You could use the following query: SELECT DISTINCT OBJECT_NAME(id) AS [OBJECT_NAME] FROM sys.syscomments WHERE…
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Last week I had to load a huge amount of data, about 500,000 rows, in a Sql Server table to make some data processing. Using the “Sql Server Import and Export Data” tool this was an easy job. After processing data in my own Sql Server, I had to reload the data to another Sql…
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I was trying to load the content of an xlsx file into a Sql Server database using the “Sql Server import and export wizard” provided by Sql Server Management Studio, and I got the following error “The ‘Microsoft.ACE.OLEDB.12.0’ provider is not registered on the local machine”. The error persisted even after the installation of the…
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Try to answer this riddle: What is the result of this SQL Server query: PRINT LEN(‘ ‘) I would answer 1, since I passed a string with one space…. but it’s the wrong answer. In this case the LEN function returns 0! Why this behavior? If you check the Sql Server documentation at https://docs.microsoft.com/en-us/sql/t-sql/functions/len-transact-sql?view=sql-server-2017 this…
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Few days ago, I got a Sql Server error using a database with a CLR assembly installed. Running my application I got the following error: “An error occurred in the Microsoft .NET Framework while trying to load assembly id 65536. The server may be running out of resources, or the assembly may not be trusted…
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Sometimes is useful to check how a certain query or a stored procedure behaves without cached data, so in this post I will show you how to reset SQL Server cache. To do the job, simply run these statements from SQL Management Studio: CHECKPOINT GO DBCC DROPCLEANBUFFERS GO DBCC FREEPROCCACHE GO