IN operator in t-sql is used in cases where we need to specify a condition e.g in WHERE clause to multiple discrete values at once. It is similar to SQL BETWEEN operator but there is one big difference. Difference between SQL operators IN and BETWEEN: BETWEEN can be used to define range which is continuous… Read More »
This operator is used in SQL whenever it is needed to prove if certain value belongs to some range. This operator is used together with “AND” command which defines given range. Operator can be used in most of the clauses but is most common in WHERE for defining limiting requirement. SQL BETWEEN Operator Syntax SELECT… Read More »
What we call a transaction in SQL is logical set or sequence of operations which belong to this transaction. SQL Transactions can be used if we perform some changes in a databases. Advantage of transactions managing is that performed changes are reversible and we always need to use command COMMIT for confirmation or use ROLLBACK… Read More »
SQL COUNT function belongs to Aggregate functions and it is one of the most easy-to-use and also most used functions of SQL. It enables user to count rows in certain column or rows in whole table. NULL records are missed out if we count number of records above certain column using sql COUNT. SQL COUNT… Read More »
EXISTS is a T-SQL operator which can be used to test existence of a result in subquery. Based on that it can perform query or some task. Sql EXISTS performs so called “Existence test”. SQL EXISTS Syntax 1) SQL Query WHERE SELECT Columns FROM dbo.Table WHERE EXISTS (SELECT columns FROM Dbo.Table2 … Read More »
REPLACE function is used to replace text string or its parts. It belongs to the category of string functions. I created big overview of T-SQL text functions some time ago. SQL REPLACE Syntax (3 arguments) SELECT REPLACE(<Column with text in which we replace part of the text>, <The string we want to replace>, <New string>)… Read More »
SQL CTE, or Common Table Expression, is essentially a temporary result set represented in the form of an expression. Once declared using the WITH clause, it can be referenced in SELECT, INSERT, DELETE, or UPDATE scripts. SQL CTE (common table expression) Syntax WITH Alias_Query AS ( SELECT Column1, Column2 FROM dbo.Table ) SELECT * FROM Alias_Query; We… Read More »
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What you will find below is a map of all components and tasks which are part of SSIS Project in SQL Server Data Tools 2015. Particular components and tasks can be found in SSIS Toolbox (see screenshot). I am going to add tutorials for SSIS and other ETL tools in the future. SSIS ToolBox –… Read More »
We can add a column to the table in two ways. First is using sql server management studio graphical interface. Second one is using SQL command ADD COLUMN. T-SQL ADD COLUMN Syntax: ALTER TABLE dbo.Table ADD <Column> <Data Type> NULL (or) NOT NULL Column will be created on the end of the table. If the… Read More »