T-SQL:检查电子邮件格式

CREATE FUNCTION dbo.IsValidEmail(@email VARCHAR(255))
RETURNS BIT
AS
BEGIN
    DECLARE @IsValid BIT
    SET @IsValid = 1

    IF @email IS NULL OR @email = ''
    BEGIN
        SET @IsValid = 0
    END
    ELSE
    BEGIN
        IF @email NOT LIKE '%@%.%'
        BEGIN
            SET @IsValid = 0
        END
    END

    RETURN @IsValid
END

SELECT email, dbo.IsValidEmail(email) AS IsValid
FROM users
WHERE dbo.IsValidEmail(email) = 0