The T-SQL Merge statement
You have a table A with new data, and a table B with old data. How do you make sure table B is refreshed with data from table A? You want to insert new records, update existing records and to … Read more →
Posts in Category ‘T-SQL’
Identity columns that are about to overflow
Identity columns are widely used as primary key columns in SQL Server tables. They can be one of the data types TINYINT, SMALLINT, INT, BIGINT, NUMERIC or DECIMAL. Each of these data types has an upper limit and when that … Read more →
Split strings to columns
A short demo on how to split strings with delimiters into columns.
Create XML with T-SQL function FOR XML
Some time ago I demonstrated how to use XQuery to map a hierarchical XML document into parent- child relational tables. You can find that article here. The other way around, (to create create XML with T-SQL), is a lot easier … Read more →
How to fill in gaps in time series
In some cases it is necessary to have an unbroken time series, for instance to have all days during a year. But what if some days are missing from the data? How can we fill in gaps in time series?
Sending HTML tables in mail from SQL Server
This post contains a template for sending HTML tables via mail in T-SQL. A prerequisite is that you have created a Database Mail Profile. If you don’t have an email server available, you can use Gmail instead as demonstrated here.
Mass editing of SQL Server objects
Ever had the need to replace a piece of code in multiple SQL Server objects (Stored Procedure, Trigger, Function or Views)? Here’s a method to search for a string in all objects, replace it with some other code, and to … Read more →
A T-SQL WHILE loop demonstration with BREAK and CONTINUE
Just a short blog post to demonstrate the use of a WHILE loop in T-SQL, together with the BREAK and CONTINUE statements.
T-SQL Pivot and Unpivot
A simple demonstration of the Pivot and Unpivot functions in T-SQL.
Max or min value from a set of columns
The min and max aggregates in SQL Server are normally used to work over rows, getting the max or min value from a set of rows. But what if you want to get the max or min value from a … Read more →