Question

我试图使用LEFT JOIN

基于他们的列加入两个表

SELECT DISTINCT ic.document_num, wps.file_name 
FROM web_pub_subfile wps
LEFT JOIN infocard_1 ic ON ic.info_card_id = wps.info_card_id
                        AND lower(ic.vault_name) LIKE N'%su-spec-release%'
WHERE wps.file_name IN ('00350.dwg','00924.dwg','00960.dwg','00973.dwg');

我以这种格式获得输出

document_num    file_name
-------------------------
NULL            00924.DWG
NULL            00960.DWG
NULL            00973.DWG
SU-SH3A081      00960.DWG
SU-SH3A148      00973.DWG

问题在于，它没有显示任何有关

00350.dwg

的内容，并在

00960.DWG and 00973.DWG

上显示重复的空值

预期的输出

document_num    file_name
-------------------------
NULL            00350.DWG
NULL            00924.DWG
SU-SH3A081      00960.DWG
SU-SH3A148      00973.DWG

有人可以帮助我吗？

Answer 1

这样的事情应该符合期望，我希望......

SELECT DISTINCT 
         ic.document_num,
         wps.file_name
FROM     web_pub_subfile wps
         LEFT JOIN infocard_1 ic ON ic.info_card_id = wps.info_card_id 
WHERE    ic.vault_name LIKE N'%su-spec-release%'
         AND ic.document_num IS NOT NULL
         AND wps.file_name IN ('00350.dwg', '00924.dwg', '00960.dwg', '00973.dwg')

Answer 2

SELECT DISTINCT 
  ic.document_num, 
  wps.file_name 
FROM
  web_pub_subfile wps
LEFT JOIN infocard_1 ic 
  ON ic.info_card_id = wps.info_card_id
  AND lower(ic.vault_name) LIKE N'%su-spec-release%'
  AND wps.file_name IN ('00350.dwg','00924.dwg','00960.dwg','00973.dwg');

我希望这种语法可以帮到你！

SQL LEFT JOIN上的重复NULL值

2 个答案: