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REGR_R2 function [Aggregate]

Computes the coefficient of determination (also referred to as R-squared or the goodness of fit statistic) for the regression line.

REGR_R2( dependent-expression , independent-expression )

REGR_R2( dependent-expression , independent-expression )
OVER ( window-spec )

window-spec : see Syntax 2 instructions in the Usage section below

dependent-expression    The variable that is affected by the independent variable.

independent-expression    The variable that influences the outcome.

This function converts its arguments to DOUBLE, performs the computation in double-precision floating point, and returns a DOUBLE as the result. If the function is applied to an empty set, then it returns NULL.

The function is applied to the set of (dependent-expression and independent-expression) pairs after eliminating all pairs for which either dependent-expression or independent-expression is NULL.

For more information about the statistical computation performed, see Mathematical formulas for the aggregate functions.

Syntax 2 represents usage as a window function in a SELECT statement. As such, elements of window-spec can be specified either in the function syntax (inline), or in conjunction with a WINDOW clause in the SELECT statement. See the window-spec definition provided in WINDOW clause.

For more information about using window functions in SELECT statements, including working examples, see Window functions.

• REGR_COUNT function [Aggregate]
• REGR_INTERCEPT function [Aggregate]
• REGR_SLOPE function [Aggregate]
• REGR_SXX function [Aggregate]
• REGR_SXY function [Aggregate]
• REGR_SYY function [Aggregate]
• REGR_AVGX function [Aggregate]
• REGR_AVGY function [Aggregate]

• SQL/2003    SQL foundation feature (T621) outside of core SQL.

The following example returns the value 0.19379959710325653.

SELECT REGR_R2( Salary, ( YEAR( NOW() ) - YEAR( BirthDate ) ) )
FROM Employees;