Daily micro-tips for C#, SQL, performance, and scalable backend engineering.
The UNIQUE constraint ensures that all values in a column are different. Both the UNIQUE and PRIMARY KEY constraints provide a guarantee for uniqueness for a column or set of columns. A PRIMARY KEY constraint automatically has a UNIQUE constraint. However, you can have many UNIQUE constraints per table, but only one PRIMARY KEY constraint […]
These 2 scripts clean all views, SPS, functions PKs, FKs and tables. 1. The First script by Adam Anderson, updated to support objects in other schemas than dbo: — check constraints select @stmt = isnull( @stmt + @n, ” ) + ‘alter table [‘ + schema_name(schema_id) + ‘].[‘ + object_name( parent_object_id ) + ‘] drop […]
There is NO way to alter computed column. You have to drop and recreate it. Let’s say you have a table with 3 column. And the 3rd one is the sum of the other two: CREATE TABLE MyTable (Column1 int, Column2 int, Column3 AS Column1 + Column2); If you want to change that computed column as multiply of the other […]
A stored procedure is a saved block of T-SQL code, such as a query to list the rows in a table. A block of T-SQL code can be saved in a T-SQL script file. You can also store the code from a script file in a stored procedure. There are several benefits that result from […]
Are you writing a query that selects data from a table with lots of columns? Does the select list we need to have all or almost all of these columns? Remember, that it is possible to drag and drop objects from Object Explorer to the Query Window. By dragging and dropping the “Columns” node under […]