A very powerful yet obscure feature in SQL is the ability to have parts of the where clause conditionally execute. Most often developers will make duplicate copies of an entire query to facilitate two different variable choices. Below is an example stored procedure to return employees that has an optional parameter to return employees based [...]
Archive of entries posted on August 2009
Add Column Constraint
To add a constraint to an existing table use the alter table statement with the add constraint command. There are four different types of constraints: Primary Key Constraints – Enforces unique values for specified column, can be referenced. Foreign Key Constraints – Enforces a reference to a primary key Unique Constraints – Ensures unique values [...]
