@cortez.connelly
To create a function in PostgreSQL, you can use the CREATE FUNCTION
statement. Here is the general syntax:
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CREATE FUNCTION function_name(parameter_list) RETURNS return_type AS $$ BEGIN -- function body goes here END; $$ LANGUAGE language_name; |
Here is an example that creates a function that calculates the area of a rectangle given its length and width:
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CREATE FUNCTION calc_rect_area(length float, width float) RETURNS float AS $$ BEGIN RETURN length * width; END; $$ LANGUAGE plpgsql; |
This function can be called as follows:
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SELECT calc_rect_area(2.5, 3.7); |
This would return the result 9.25
.
You can also specify the parameters as IN, OUT, or INOUT to indicate their direction (input, output, or both). For example:
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CREATE FUNCTION swap(IN x int, INOUT y int) RETURNS void AS $$ BEGIN y := x; x := y; END; $$ LANGUAGE plpgsql; |
This function can be called as follows:
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SELECT swap(1, 2); |
This would return no result, but the values of x
and y
would be swapped within the function.
I hope this helps! Let me know if you have any questions.