About the SQL Server MERGE Statement
The main application area for the SQL Server MERGE statement is a data warehouse environment, where tables need to be refreshed periodically with new data arriving from OLTP systems. Learn more.
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SQL Server Nonrecursive Queries with Common Table Expressions
The nonrecursive form of a CTE can be used as an alternative to derived tables and views. Learn how.
Read MoreWhen and How to Apply SQL Server Derived Tables
Apply SQL Server derived tables when the use of column aliases is not possible because another clause is processed by the SQL translator before the alias name is known. Learn more.
Read MoreWhich Should You Use–SQL Server Joins or Subqueries
Writing a SQL Server SELECT statement using the join operator is can help the Database Engine to find a more efficient strategy for retrieving the appropriate data. Learn how.
Read MoreWorking with SQL Server Outer Joins
In SQL Server, sometimes it is necessary to retrieve, in addition to the matching rows, the unmatched rows from one or both of the tables. Such an operation is called an outer join.
Read MoreJoining More than Two SQL Server Tables
The SQL Server Database Engine sets the maximum number of tables that can be joined in a SELECT statement is 64. Learn more.
Read MoreSQL Server SELECT Statement and IDENTITY Property
The SQL Server IDENTITY property lets you specify a counter of values for a specific column of a table. You can use it to let the system generate unique numeric values for the table column of your choice. Learn more.
Read MoreUnderstanding SQL Server Queries Involving NULL Values
A NULL in the CREATE TABLE statement specifies that a special value called NULL is allowed in the column. Learn how these values differ from all other values in a SQL Server database.
Read MoreAbout the SQL Server Foreign Key Clause
A SQL Server foreign key is a column or group of columns in one table that contains values that match the primary key values in the same or another table. Learn more.
Read MoreSQL Server CREATE TABLE and Declarative Integrity Constraints
The task of maintaining integrity constraints can be handled by the user in application programs or by the DBMS. Learn more about SQL Server CREATE TABLE and declarative integrity constraints.
Read MoreUnderstanding SQL Server NULL Values
A NULL value in SQL Server is a special value that may be assigned to a column. This value normally is used when information in a column is unknown or not applicable. Learn more.
Read MoreSQL Server Debugging
Since SQL Server 2008, you can debug SQL code using the existing debugger. And SQL Server 2012 enhances the functionality of the SQL Server Management Studio Debugger with several new features. Learn more.
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