SQL Question For Interview

sql question for interview represents a topic that has garnered significant attention and interest. sql - NOT IN vs NOT EXISTS - Stack Overflow. Which of these queries is the faster? NOT EXISTS: SELECT ProductID, ProductName FROM Northwind..Products p WHERE NOT EXISTS ( SELECT 1 FROM Northwind..[Order Details] od WHERE p. SQL asterisk(*) all possible uses - Stack Overflow. It is used in sql-server for xml. In the code below, aliasing the subquery as ' [*]' means that COLUMN_NAME and DATA_TYPE xml nodes output on the same level as TABLE_SCHEMA and TABLE_NAME.

Should I use != or <> for not equal in T-SQL? Yes; Microsoft themselves recommend using <> over != specifically for ANSI compliance, e.g. in Microsoft Press training kit for 70-461 exam, "Querying Microsoft SQL Server", they say "As an example of when to choose the standard form, T-SQL supports two “not equal to” operators: <> and !=. The former is standard and the latter is not. Building on this, sQL WITH clause example - Stack Overflow.

353 The SQL WITH clause was introduced by Oracle in the Oracle 9i release 2 database. The SQL WITH clause allows you to give a sub-query block a name (a process also called sub-query refactoring), which can be referenced in several places within the main SQL query. The name assigned to the sub-query is treated as though it was an inline view or ... How do I perform an IF...THEN in an SQL SELECT?. 2059 The CASE statement is the closest to IF in SQL and is supported on all versions of SQL Server.

Building on this, sQL: IF clause within WHERE clause - Stack Overflow. Is it possible to use an IF clause within a WHERE clause in MS SQL? Example: WHERE IF IsNumeric(@OrderNumber) = 1 OrderNumber = @OrderNumber ELSE OrderNumber LIKE '%' + @ sql - Delete duplicate rows keeping the first row - Stack Overflow. Additionally, 10 To delete the duplicate rows from the table in SQL Server, you follow these steps: Find duplicate rows using GROUP BY clause or ROW_NUMBER () function. Similarly, use DELETE statement to remove the duplicate rows.

Setting up a sample table Remove all spaces from a string in SQL Server - Stack Overflow. Equally important, what is the best way to remove all spaces from a string in SQL Server 2008? LTRIM(RTRIM(' a b ')) would remove all spaces at the right and left of the string, but I also need to remove the space ... Convert Rows to columns using 'Pivot' in SQL Server.

Pivot is one of the SQL operator which is used to turn the unique data from one column into multiple column in the output. This is also mean by transforming the rows into columns (rotating table). Let us consider this table, If I want to filter this data based on the types of product (Speaker, Glass, Headset) by each customer, then use Pivot ...