Question

我在SQL Server中存储过程时遇到了一些问题。我正在尝试选择一个电话号码来获取Id，但我遇到的问题是列PhoneExtension定义为int并允许空值。

以下代码有效，但可能无法返回所需的结果（可能存在具有多个扩展名的相同电话号码）

CREATE PROCEDURE [dbo].[GetPhoneNumberId]
    @phoneNumber INT,
    @phoneExtension INT = NULL,
    @countryCode INT = 1,
    @PhoneNumberId INT OUTPUT
AS
BEGIN
    SET @PhoneNumberId = (SELECT TOP 1 PhoneNumberId
                          FROM PhoneNumbers
                          WHERE PhoneNumber = @phoneNumber
                            AND PhoneCountryCode = @countryCode);
END

如果@phoneExtension为NULL且PhoneNumbers表中的记录NULL为PhoneExtenstion

，则下一个不起作用

CREATE PROCEDURE [dbo].[GetPhoneNumberId]
    @phoneNumber INT,
    @phoneExtension INT = NULL,
    @countryCode INT = 1,
    @PhoneNumberId INT OUTPUT
AS
BEGIN
    SET @PhoneNumberId = (SELECT TOP 1 PhoneNumberId
                          FROM PhoneNumbers
                          WHERE PhoneNumber = @phoneNumber
                            AND PhoneExtension = @phoneExtension
                            AND PhoneCountryCode = @countryCode);
END

Answer 1

你可以试试这个：

CREATE PROCEDURE [dbo].[GetPhoneNumberId]
    @phoneNumber INT,
    @phoneExtension INT = NULL,
    @countryCode INT = 1,
    @PhoneNumberId INT OUTPUT
AS
BEGIN
    SET @PhoneNumberId = (SELECT TOP 1 PhoneNumberId
                          FROM PhoneNumbers
                          WHERE PhoneNumber = @phoneNumber
                            AND (ISNULL(PhoneExtension, '') = ISNULL(@phoneExtension, ''))
                            AND PhoneCountryCode = @countryCode);
END

Answer 2

你可以试试这个：

CREATE PROCEDURE [dbo].[GetPhoneNumberId]
    @phoneNumber INT,
    @phoneExtension INT = NULL,
    @countryCode INT = 1,
    @PhoneNumberId INT OUTPUT
AS
BEGIN
    SET @PhoneNumberId = (SELECT TOP 1 PhoneNumberId
                          FROM PhoneNumbers
                          WHERE PhoneNumber = @phoneNumber
                            AND (
                                PhoneExtension = @phoneExtension
                                OR 
                                (PhoneExtension IS NULL AND @phoneExtension IS NULL)
                                )
                            AND PhoneCountryCode = @countryCode);
END

Answer 3

更改

PhoneExtension = @phoneExtension

到

PhoneExtension = ISNULL(@phoneExtension, PhoneExtension)

当@phoneExtension为NULL时，此过滤条件基本上会被忽略。

存储过程中的T-SQL Null比较

3 个答案: