Function is
a database object
in SQL Server. Basically, it is a set of SQL statements that accept only input parameters, perform actions and return the result. Function can return an only single value or a table. We can’t use a function to Insert, Update, Delete records in the database table(s).
What is function in SQL Server with example?
Functions can be used anywhere in SQL, like AVG, COUNT, SUM, MIN, DATE and so on with select statements. Functions
compile every time
. Functions must return a value or result. Functions only work with input parameters.
What is an SQL function?
A function is
a set of SQL statements that perform a specific task
. Functions foster code reusability. If you have to repeatedly write large SQL scripts to perform the same task, you can create a function that performs that task. Next time instead of rewriting the SQL, you can simply call that function.
Which are SQL function give example?
| Function Description | SUM() Used to return the sum of a group of values. | COUNT() Returns the number of rows either based on a condition, or without a condition. | AVG() Used to calculate the average value of a numeric column. | MIN() This function returns the minimum value of a column. |
|---|
What are different functions in SQL?
- Aggregate functions: These functions are used to do operations from the values of the column and a single value is returned. AVG() COUNT() FIRST() LAST() …
- Scalar functions: These functions are based on user input, these too returns single value. UCASE() LCASE() MID() LEN()
What is difference between function and procedure?
A function is used to calculate result using given inputs. A procedure is used to perform certain task in order. … A function returns a
value
and control to calling function or code. A procedure returns the control but not any value to calling function or code.
What is difference between stored procedure and function?
The function must return a value but in Stored Procedure it is
optional
. Even a procedure can return zero or n values. Functions can have only input parameters for it whereas Procedures can have input or output parameters. Functions can be called from Procedure whereas Procedures cannot be called from a Function.
What triggers SQL?
A SQL trigger is
a database object which fires when an event occurs in a database
. We can execute a SQL query that will “do something” in a database when a change occurs on a database table such as a record is inserted or updated or deleted. For example, a trigger can be set on a record insert in a database table.
What is SQL transaction?
A transaction is
a sequence of operations performed (using one or more SQL statements) on a database as a single logical unit of work
. The effects of all the SQL statements in a transaction can be either all committed (applied to the database) or all rolled back (undone from the database).
How do you write a formula in SQL query?
- Click. …
- Specify that you want to create a select query (“Select” option). …
- The query description window appears.
- Give a name and a caption to the query:
- In the left section of the description window, choose the file items that will be used.
What is scalar query?
A scalar subquery expression is
a subquery that returns exactly one column value from one row
. The value of the scalar subquery expression is the value of the select list item of the subquery. If the subquery returns 0 rows, then the value of the scalar subquery expression is NULL .
What is equi join?
An equi join is
a type of join that combines tables based on matching values in specified columns
. … The column names do not need to be the same. The resultant table contains repeated columns. It is possible to perform an equi join on more than two tables.
What is data integrity in SQL?
Data Integrity is
used to maintain Accuracy and consistency of data in the Table
. Data Integrity is used to maintain accuracy and consistency of data in a table. Classification of Data Integrity. System/Pre Defined Integrity.
WHAT IS function and procedure in SQL?
“A procedures or function is a group or set of SQL and PL/SQL statements
that perform a specific task
.” A function and procedure is a named PL/SQL Block which is similar . The major difference between a procedure and a function is, a function must always return a value, but a procedure may or may not return a value.
What all character types are possible in SQL?
| Data Type Lower Range Storage | Char(n) 0 characters N bytes | Varchar(n) 0 characters n bytes + 2 bytes | Varchar (max) 0 characters n bytes + 2 bytes ~ 2 GB | Text 0 chars n bytes + 4 bytes |
|---|
How do you write a trigger?
- CREATE [OR REPLACE ] TRIGGER trigger_name.
- {BEFORE | AFTER | INSTEAD OF }
- {INSERT [OR] | UPDATE [OR] | DELETE}
- [OF col_name]
- ON table_name.
- [REFERENCING OLD AS o NEW AS n]
- [FOR EACH ROW]
- WHEN (condition)
