The language of the Database Engine, Transact-SQL, has the same basic features as other common programming languages: Literal values (also called constants)DelimitersCommentsIdentifiersReserved keywords The following sections describe these … [Read more...] about SQL’s Basic Objects (Literal values, Delimiters, Comments, Identifiers)
SQL Components - SQL Server 2012
This chapter introduces the elementary objects and basic operators supported by the Transact-SQL language. First, the basic language elements, including constants, identifiers, and delimiters, are described. Then, because every elementary object has a corresponding data type, data types are discussed in detail. Additionally, all existing operators and functions are explained. At the end of the chapter, NULL values are introduced.
All the data values of a column must be of the same data type. (The only exception specifies the values of the SQL_VARIANT data type.) Transact-SQL uses different data types, which can be categorized as follows: Numeric data typesCharacter data … [Read more...] about Data Types (Numeric, Character, Temporal etc)
Since SQL Server 2008, there are two different storage options, each of which allows you to store LOBs and to save storage space: FILESTREAMSparse columns The following subsections describe these options. FILESTREAM Storage As you already … [Read more...] about Storage Options (FILESTREAM, Sparse columns)
Transact-SQL functions can be either aggregate functions or scalar functions. The following sections describe these function types. Aggregate Functions Aggregate functions are applied to a group of data values from a column. Aggregate functions … [Read more...] about Transact-SQL Functions (Aggregate, Scalar)
Scalar operators are used for operations with scalar values. Transact-SQL supports numeric and Boolean operators as well as concatenation. There are unary and binary arithmetic operators. Unary operators are + and – (as signs). Binary arithmetic … [Read more...] about Scalar Operators, Global Variables
A NULL value 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. For example, in the case of an unknown home telephone number for a company’s employee, it is … [Read more...] about NULL Values in SQL Server