These are explained as following below. @@SERVERNAME : This is used to find the name of the machine/computer on which SQL Server is running. Example – Select @@servername.
What is the use of @@ in SQL?
@@ is used to prefix internal statistical and metadata functions that return information about how the SQL Server is configured, not specific to any particular database.
What is @@ options in SQL Server?
There is a variable in SQL Server called @@OPTIONS. This contains all of the settings that you have configured using the SET command. However, understanding the values inside of this variable can be a bit cumbersome. This article will show you a quick way to determine what settings you have in your environment.
What is difference between and @@ in SQL?
There is no difference. The rules for variables state that they start with an ‘@’ character and follow the rules for identifiers.
What is like %% in SQL?
The LIKE operator is used in a WHERE clause to search for a specified pattern in a column. There are two wildcards often used in conjunction with the LIKE operator: The percent sign (%) represents zero, one, or multiple characters. The underscore sign (_) represents one, single character.
What is @@ Transcount in SQL Server?
@@TRANCOUNT (Transact-SQL) Returns the number of BEGIN TRANSACTION statements that have occurred on the current connection.
Is identity a primary key?
An identity column differs from a primary key in that its values are managed by the server and usually cannot be modified. In many cases an identity column is used as a primary key; however, this is not always the case.
What are the 4 types of options?
There are four basic options positions: buying a call option, selling a call option, buying a put option, and selling a put option. With call options, the buyer is betting that the market price of an underlying asset will exceed a predetermined price, called the strike price, while the seller is betting it won’t.
Which SQL Server is best?
Is != Or <> better in SQL?
If != and <> both are the same, which one should be used in SQL queries? Here is the answer – You can use either != or <> both in your queries as both technically same but I prefer to use <> as that is SQL-92 standard.
Is NULL and NULL in SQL?
In SQL null is not equal ( = ) to anything—not even to another null . According to the three-valued logic of SQL, the result of null = null is not true but unknown. SQL has the is [not] null predicate to test if a particular value is null .
What is the use of && in SQL?
Double ampersands (&&) have the same functionality as the AND operator. The following matrix shows possible input value combinations and return values.
Why semicolon is used in SQL?
Some database systems require a semicolon at the end of each SQL statement. Semicolon is the standard way to separate each SQL statement in database systems that allow more than one SQL statement to be executed in the same call to the server.
What does <> mean in MySQL?
The symbol <> in MySQL is same as not equal to operator (!=). Both gives the result in boolean or tinyint(1). If the condition becomes true, then the result will be 1 otherwise 0. Case 1 − Using !=
What does <> mean in DBMS?
It means ‘not equal to’.
Is NULL or is not NULL?
The IS NULL condition is satisfied if the column contains a null value or if the expression cannot be evaluated because it contains one or more null values. If you use the IS NOT NULL operator, the condition is satisfied when the operand is column value that is not null, or an expression that does not evaluate to null.
How do I use multiple wildcards in SQL?
There are two wildcards used in conjunction with the LIKE operator. The percent sign represents zero, one or multiple characters. The underscore represents a single number or character. These symbols can be used in combinations.
What is coalesce in SQL?
Definition and Usage. The COALESCE() function returns the first non-null value in a list.
Why set Nocount on is used in SQL?
SET NOCOUNT ON prevents the sending of DONEINPROC messages to the client for each statement in a stored procedure.vor 4 Tagen
What is @@ Fetch_status in SQL Server?
@@FETCH_STATUS (Transact-SQL) This function returns the status of the last cursor FETCH statement issued against any cursor currently opened by the connection.
What are the 5 Sublanguages of SQL?
SQL includes 5 types of sub-languages that are DDL, DML, DQL/DRL, DCL, and TCL.
Can I rollback after commit?
COMMIT permanently saves the changes made by the current transaction. ROLLBACK undo the changes made by the current transaction. 2. The transaction can not undo changes after COMMIT execution.