Data types and Precedence of convert types SQL Server associates columns, expressions, variables, and parameters with data types. Data types determine what kind of data can be stored in the field: Integers, characters, dates, money, binary strings, etc. SQL Server supplies several built-in data types but you can also define custom types Built-in data types … Continue reading Data types
Temporary Tables
Sometimes we need to use temporary tables to do aggregations, joins or to simplify the job. SQL Server supports a number of options that you can use to store data temporarily. You can use temporary tables and table variables, before we start with codes we need know some concepts. Local temporary tables are named with … Continue reading Temporary Tables
The Meaning of “Set-Based”
The term set-based is used to describe an approach to handle querying tasks and is based on principles from the relational model. Remember that the relational model is based in part on mathematical set theory. Set-based solutions use T-SQL queries, which operate on the input tables as sets of rows. Such solutions are contrasted with … Continue reading The Meaning of “Set-Based”
Structured Query Language
By a “set” we mean any collection M into a whole of definite, distinct objects m (which are called the “elements” of M) of our perception or of our thought. —George Cantor, in “Georg Cantor” by Joseph W. Dauben (Princeton University Press, 1990) Standard SQL is based on the relational model, which is a mathematical … Continue reading Structured Query Language
Thinking in Sets
Thinkins in sets is a great book by Joe Celko's. This book tell us about concepts how we need to think when we were working with databases. Columns are not fields, rows are not records and tables are note files, hence SQL is declarative, not procedural. There is no sequential access or ordering in table, … Continue reading Thinking in Sets
