Introduction In SQL , learning unpivoting of data is as important as learning pivoting of data.Sometimes we need to transform data from column to rows for efficient analysis. The UNPIVOT function is useful when you have data in a pivoted format, with values spread across multiple columns, and you want to convert it back into …
In SQL Server, You can use PIVOT to convert rows into columns. Syntax: <non-pivoted column> are columns which are not intended for pivot[pivoted column1], [pivoted column2] are columns which we want to pivotThe Select statement in FROM clause is for source table<aggregate_function> is useful when we have two or more rows with similar primary key …
ROW_NUMER() SQL ROW_NUMBER() is used to number the result set. The return type is integers. Syntax: EXAMPLE: For example purpose we will use table named ‘EMPLOYEE’. Lets use ROW_NUMBER() to number the rows. You can see a new column is created and numbers have been given according to ‘SALARY’ . We used ORDER BY clause …
SQL LIKE SQL LIKE operators are used in conjunction with WHERE clause to find patterns in the strings. Two wild card characters are used with LIKE operators-‘%’ is used to represent zero, one, or multiple character‘_’ is used when you want to represent only one character Syntax: WHERE Clause in above statement will match with …
SQL case are used to evaluate a set of expression and return the expression that fulfils the condition. There are two types of SQL CASE – The simple CASE expression compares an expression to a set of simple expressions to determine the result. The searched CASE expression evaluates a set of Boolean expressions to determine …
SQL TOP is used to control the amount of rows produced by the SELECT statement. When you are working with big datasets(millions of rows), it is important to keep in mind that SELECT statements use processing power of the system. SQL TOP Limits the rows returned in a query result set to a specified number …
SQL LEAD Function SQL LEAD function is used by the user if he wants to check or compare value present in the next rows With the current row. Syntax: The first argument of LEAD function is the column name from which you want to fetch the value. The offset value is the number of rows …
What are SQL CTE? SQL CTE or common table expressions are temporary tables created by the result of some other query. They have their name and can be referenced in SQL statements.They are created using WITH clause encapsulating SQL statements. Syntax Of CTE: EXAMPLE: For Example we are going to use the EMPLOYEE table. For …
SQL Common Table Expression(CTE) -CLEAR And PRECISE Read More »
SQL views are virtual tables created by the user. SQL views can also be considered as a subset of tables.SQL views provide security features to users as they can be used to keep the main table safe or inaccessible to others. Syntax of Views: Updating View: Dropping View: EXAMPLE: We will use the following table …
What is subquery? Subqueries in SQL are queries inside queries. Users can specify a Query in either the FROM clause or WHERE clause. The internal query filters rows and makes it easier for the external query to operate. You can bypass the use of subquery but it will make the query long with less readability. …
SQL SubQueries Basic- What are they? How to use them ? Read More »
