Did you know you can include a SELECT statement within another SELECT statement? When a SELECT statement is embedded within another statement it is known as a subquery. There are two types of subqueries: basic subquery and correlated subquery. In this article I will be discussing both types of subqueries and will be providing examples … Read more
Sometimes when working with very large sets of data, you may not want to return all of the data at once. I discussed using TOP in my previous article, which allowed you to only get a number of rows from the start of the results from a query. However, if you want to see the … Read more
There might be a time when you might want to return just a few rows of a result set, instead of the complete set. This might be useful if you want to just validate a selection criteria or a few rows of data. For whatever the reason the TOP clause can be used to return a specific number or a percentage of rows from a result set. This article will cover using the TOP clause in a SELECT statement and how it can be used to return a partial set of records.… Read more
Once data is in a table it needs to be maintained. New records will need to be added, and existing records will need to be updated, and/or deleted. To keep data maintained, the insert, update or delete actions may need to be performed. This article will show how those three data manipulation language (DML) actions can be synchronized together within a single basic MERGE statement.… Read more
Over time data in SQL Server tables needs to be modified. There are two major different aspects of modifying data: updating and deleting. In my last article “Updating SQL Server Data” I discussed using the UPDATE statement to change data in existing rows of a SQL Server table. In this article I will be demonstrating … Read more
Once data is inserted into a table, data typically needs to be maintained as time goes on. To make changes to an existing row or a number of rows, in a table, the UPDATE statement is used. This article shows how to use the UPDATE statement to modify data within a SQL Server table. Syntax … Read more
Before data can be read from of a SQL Server database table, the table needs to contain rows of data. One of the most typical ways to get data into a table is to use the INSERT statement. One row or multiple rows can be inserted with a single execution of an INSERT statement. You … Read more
To guarantee the order of a result set, you must use an ORDER BY clause. In this article, Greg Larsen explains what you need to know about ORDER BY.… Read more
It’s important to choose the right datatypes when designing a database. Greg Larsen explains the differences between CHAR, VARCHAR and VARCHAR(MAX).… Read more
SQL Server provides two ways to include an incrementing number in a table. Greg Larsen explains how to replace an identity column with a sequence number.… Read more
Developers can work with multiple range values at once using sp_sequence_get_range. Greg Larsen explains how to return multiple sequence numbers with sp_sequence_get_range.… Read more
SQL Server sequence objects have several properties that control how they behave. Greg Larson explains the options of using SQL Server sequence objects.… Read more
SQL Server sequence objects can be used in place of identity columns. In this article, Greg Larsen explains how to set up and use sequence objects.… Read more
SQL Server identity columns are easy to add to a table, but you must understand how they work to use them effectively. In this article, Greg Larsen explains the nuances of SQL Server identity columns.… Read more
The SQL Server identity column is used to populate a column with incrementing numbers on insert. In this article, Greg Larsen explains how it works.… Read more
