TSQL Azure SQL Server 左字符索引

Question

我有一个 TSQL 语句，它查询单个表以查找重复的街道地址号码。例如，“123 Street”匹配“123 St.”。我使用 CHARINDEX 通过选择字符串左侧但在空格之前的字符来分隔字符串，这些字符几乎总是如下所示：

    "SELECT NewId() as NewId," +
            //We rename the dbo.User table as "a" then rename it again as "b" so we can look for duplicate Street Address numbers
            "a.Id AS LeftID,a.DateSubmitted AS LeftDateSubmitted,a.Updated AS LeftUpdated," +
            "a.Status AS LeftStatus,a.StreetAddress AS LeftStreetAddress," +

            "b.Id AS RightID,b.DateSubmitted AS RightDateSubmitted,b.Updated AS RightUpdated," +
            "b.Status AS RightStatus,b.StreetAddress AS RightStreetAddress " +

            //We join the 2 virtual dbo.User tables where table b Id's are greater than table a meaning b records are newer
            "FROM [User] a JOIN [User] b ON b.Id > a.Id AND " +

            //LEFT selects the left most characters (usually numbers) in the StreetAddress field string before the space ' '
            //and eliminates the rest of the address isolating just the street address numbers for matching
            "LEFT(a.StreetAddress,CHARINDEX(' ',a.StreetAddress)) = LEFT(b.StreetAddress,CHARINDEX(' ',b.StreetAddress)) " +

            //Don't show orange or blue status records
            "AND b.Status != 'Orange' AND a.Status != 'Orange' AND a.Status != 'Blue' AND b.Status != 'Blue' " +

            //If a b record (newer) is red then ignore because it is completed and ignore a records (oldest) older than 90 days
            "WHERE a.DateSubmitted >= (GetDate() - 90) AND b.Status != 'Red' " +

            //Show newest records first
            "ORDER BY b.DateSubmitted DESC"

这一直运作得相当好，直到今天我们注意到如果该人以所有大写字母输入地址，则会出现误报，如下所示：

我的使用理解：

    LEFT(a.StreetAddress,CHARINDEX(' ',a.StreetAddress))

在用于我的 JOIN 的空间之前会导致最左边的字符，但上图显示不应该发生的匹配？请帮助 SQL 初学者...

Answer 1

我认为您发送到数据库服务器以获取这些结果的查询并不是您使用该代码生成的确切查询。不仅地址匹配不正确...您还可以看到b 中的ID 小于a。在将查询发送到服务器的位置设置一个断点并检查查询字符串并验证您真正发送的内容。