连接两个表将ON条件存储为字符串的TSQL方法

如何解决连接两个表将ON条件存储为字符串的TSQL方法

我基本上是想联接两个表，其中联接条件存储为字符串。

• 我在TableA中存储的数据包括字段TREATY_NO和CO_CODE。

• 我也有下面所示的TableB。我试图返回LookupCode字段为true的IncomingData。

+---------------------------------------------------------------------------------------+------------------------------------------+
|                                     IncomingData                                      |                  LookupCode              |
+---------------------------------------------------------------------------------------+------------------------------------------+
| CHARINDEX('99FW',TREATY_NO,3)>0 AND (CO_CODE='PAZ' OR CO_CODE='PNJ' OR CO_CODE='PRU') | '5-0089-2013-0500-01-A-2013-Y-USD-AL-01' |
| CHARINDEX('99FV',3)>0 AND (CO_CODE='PAZ' OR CO_CODE='PNJ' OR CO_CODE='PRU') | '5-0089-2013-0500-01-A-2013-Y-USD-AL-01' |
| CHARINDEX('99FK',3)>0 AND (CO_CODE='PAZ' OR CO_CODE='PNJ' OR CO_CODE='PRU') | '5-0089-2013-0500-01-A-2013-Y-USD-AL-01' |
| CHARINDEX('99FL',3)>0 AND (CO_CODE='PAZ' OR CO_CODE='PNJ' OR CO_CODE='PRU') | '5-0089-2013-0500-01-A-2013-Y-USD-AL-01' |
+---------------------------------------------------------------------------------------+------------------------------------------+

例如，如果TableA中的行包含TREATY_NO = 'ABC99FWTZ'和CO_CODE = 'PAZ'，则LookupCode应该= '5-0089-2013-0500-01-A-2013-Y-USD-AL-01'

+-----------+---------+----------------------------------------+
| TREATY_NO | CO_CODE |               LookupCode               |
+-----------+---------+----------------------------------------+
| ABC99FWTZ | PAZ     | 5-0089-2013-0500-01-A-2013-Y-USD-AL-01 |
+-----------+---------+----------------------------------------+

我确定必须有一种方法可以执行此操作，但是我不知道要搜索什么。我已经研究过用于逐行执行此操作的游标，但是设置结果似乎是一个更好的解决方案。

我也一直试图遵循这个问题的第一个答案。但是问题足够不同了。 SQL Server query condition as a text stored in a table column

即使是我要解决的问题的关键字也会很有帮助。

谢谢！

解决方法

我建议您更改问题的设计。我想不出任何有效的方法。但是，如果这是一项一次性任务，则可以将游标与动态Sql结合使用以使其工作。例如，

--we declare the necessary variables that we will use
DECLARE @filterText as VARCHAR(512)
DECLARE @sqlText as VARCHAR(1024)

DECLARE @TREATY_NO as VARCHAR(24)
SET @TREATY_NO = 'ABC99FWTZ'
DECLARE @CO_CODE as VARCHAR(24)
SET @CO_CODE = 'PAZ'

DECLARE @tempStr AS VARCHAR(512)

--we init a cursor that will get the filter from the tableB which then we create a dynamic SQL
DECLARE db_cursor CURSOR FOR 
SELECT IncomingData 
FROM TableB

OPEN db_cursor  
FETCH NEXT FROM db_cursor INTO @filterText  

WHILE @@FETCH_STATUS = 0  
BEGIN  
      --we replace the variables from the text as parameters
      @tempStr = REPLACE(@filterText,'TREATY_NO','@TREATY_NO')
      @tempStr = REPLACE(@filterText,'CO_CODE','@CO_CODE')
      
      --we create the SQL query as a string where the WHERE check first the row to be the one from the cursor and then the actual filter if it is true or not
      @sqlText = 'SELECT @TREATY_NO,@CO_CODE,LookupCode FROM TableB WHERE @filterText = IncomeData AND ' + @tempStr

      --we execute the select
      EXEC (@sqlText)

      FETCH NEXT FROM db_cursor INTO @filterText 
END 

CLOSE db_cursor  
DEALLOCATE db_cursor