mysql - 如果 t1.uniqueNumber != t2.uniqueNumber，则从 t1 中选择全部

Question

让我描述一下我的需求......

我的数据库有2个MySQL表。我将表名称称为入库和出库。首先，我在库存中插入了 15 行，每个条目都有一个唯一的编号作为序列号。

mysql> select stockin_id, serialno, description from stockin limit 0,15;
+------------+------------+------------------------------------------+
| stockin_id | serialno   | description                              |
+------------+------------+------------------------------------------+
|          1 | KDR0000001 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|          2 | KDR0000002 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|          3 | KDR0000003 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|          4 | KDR0000004 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|          5 | KDR0000005 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|          6 | KDR0000006 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|          7 | KDR0000007 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|          8 | KDR0000008 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|          9 | KDR0000009 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|         10 | KDR0000010 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|         11 | T22ALT5786 | PRINTED BRD ASSMBLY                      |
|         12 | TU82956450 | FUNCTIONAL UNIT/GSM DXU-21               |
|         13 | X510239240 | FUNCTIONAL UNIT/GSM DXU-21               |
|         14 | TD36843873 | PRINTED BOARD ASSEMB/RP4-F               |
|         15 | TD36843908 | PRINTED BOARD ASSEMB/RP4-F               |
+------------+------------+------------------------------------------+
15 rows in set (0.00 sec)

现在，我已经从库存产品中转移了一些具有相同序列号的产品，这些产品存储在缺货表中，如下-

mysql> select stockout_id, serialno, description from stockout limit 0,15;
+------------+------------+------------------------------------------+
| stockin_id | serialno   | description                              |
+------------+------------+------------------------------------------+
|          1 | KDR0000001 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|          2 | KDR0000002 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|          3 | KDR0000003 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
|          4 | KDR0000004 | DATA CARRIER/FLASH CARD WITH RBS 2000 SW |
+------------+------------+------------------------------------------+
4 rows in set (0.00 sec)

现在，我想从库存中选择准确的现有库存条目。我怎样才能实现？

Answer 1

有几种方法可以做到这一点

SELECT  *
FROM    stockin si  
WHERE   NOT EXISTS  (
                        SELECT  1
                        FROM    stockout so 
                        WHERE   si.serialno = so.serialno
                    )

或者

SELECT  *
FROM    stockin si  
WHERE   si.serialno NOT IN  (
                                SELECT  so.serialno
                                FROM    stockout so 
                            )

如果您知道表 stockin 和 stockout 中的条目是唯一的

SELECT  *
FROM    stockin si LEFT JOIN
        stockout so ON  si.serialno = so.serialno
WHERE   so.serialno IS NULL

我建议 yopu 使用您阅读时最有意义的那个，然后才开始担心性能。