coalesce:
COALESCE is a SQL function that returns the first non-NULL expression among its arguments. COALESCE() is ANSI standard and may be used instead of vendor-specific alternatives such as ISNULL(), NVL() or IFNULL().
COALESCE is a SQL function that returns the first non-NULL expression among its arguments. COALESCE() is ANSI standard and may be used instead of vendor-specific alternatives such as ISNULL(), NVL() or IFNULL().
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