What are table functions in SQL?
Creating SQL table functions
- Define the CREATE FUNCTION (table) statement: Specify a name for the function. Specify a name and data type for each input parameter. Specify the routine attributes. Specify the RETURNS TABLE keyword.
- Execute the CREATE FUNCTION (table) statement from a supported interface.
What is a table value function?
A table-valued function is a user-defined function that returns data of a table type. The return type of a table-valued function is a table, therefore, you can use the table-valued function just like you would use a table.
How do table valued functions work?
A table-valued function returns a single rowset (unlike stored procedures, which can return multiple result shapes). Because the return type of a table-valued function is Table , you can use a table-valued function anywhere in SQL that you can use a table.
What are table functions?
Table functions are functions that produce a set of rows, made up of either base (scalar) data types, or composite (multi-column) data types. They are used like a table, view, or subselect in the FROM clause of a query.
How do you write a function table?
Define the CREATE FUNCTION (table) statement:
- Specify a name for the function.
- Specify a name and data type for each input parameter.
- Specify the routine attributes.
- Specify the RETURNS TABLE keyword.
- Specify the BEGIN ATOMIC keyword to introduce the function-body.
- Specify the function body.
What is the use of table-valued function in SQL Server?
A table-valued function is a function that returns data of table type. In this example we will create an inline table-valued function that will retrieve records of all the students whose DOB is less than the DOB passed to the function.
What is SQL function with example?
Aggregate SQL Functions
| 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. |
How do you write a function in SQL?
Procedure
- Specify a name for the function.
- Specify a name and data type for each input parameter.
- Specify the RETURNS keyword and the data type of the scalar return value.
- Specify the BEGIN keyword to introduce the function-body.
- Specify the function body.
- Specify the END keyword.
Can we use temp table in SQL Server?
You cannot use TEMP table (with # sign) in functions. But you CAN use Table variable (Declare @vTable Table (intcol int,…)) in functions. The limitation is that you CANNOT create index on table variables.