60 lines
2.1 KiB
Markdown
60 lines
2.1 KiB
Markdown
---
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title: SQL Right Join
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localeTitle: SQL Right Join
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---
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## SQL Right Join
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### 使用示例
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对于本指南，我们将讨论SQL RIGHT JOIN。
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### 正确的加入
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RIGHT JOIN关键字返回右表（table2）中的所有记录，以及左表（table1）中的匹配记录。当没有匹配时，结果从左侧为NULL。
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```sql
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SELECT *
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FROM table1
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RIGHT JOIN table2
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ON table1.column_name = table2.column_name;
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```
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### 完整的表格列表供参考
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食物或左表数据
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```text
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+---------+--------------+-----------+------------+
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| ITEM_ID | ITEM_NAME | ITEM_UNIT | COMPANY_ID |
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+---------+--------------+-----------+------------+
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| 1 | Chex Mix | Pcs | 16 |
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| 6 | Cheez-It | Pcs | 15 |
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| 2 | BN Biscuit | Pcs | 15 |
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| 3 | Mighty Munch | Pcs | 17 |
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| 4 | Pot Rice | Pcs | 15 |
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| 5 | Jaffa Cakes | Pcs | 18 |
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| 7 | Salt n Shake | Pcs | |
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+---------+--------------+-----------+------------+
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company or RIGHT table data
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```
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文本 + ------------ + -------- + -------------- + |公司_ID |公司_名称| COMPANY\_CITY | + ------------ + -------- + -------------- + | 18 |全部订购|波士顿| | 15 |杰克希尔有限公司|伦敦| | 16 | Akas Foods |德里| | 17 |美食家。 |伦敦| | 19 | SIP-正撕咬。 |纽约| + ------------ + -------- + -------------- +
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```
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To get company name from company table and company ID, item name columns from foods table, the following SQL statement can be used:
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```
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SQL SELECT company.company _id，company.company_ name， company.company _city，foods.company_ id，foods.item _名称 来自公司 正确的食物 ON company.company_ id = foods.company\_id;
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```
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OUTPUT
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```
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文本 公司_ID公司_名称公司_城市公司_ ID ITEM\_NAME
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* * *
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18订购所有波士顿18 Jaffa蛋糕 15杰克山有限公司伦敦15锅饭 15 Jack Hill Ltd伦敦15 BN饼干 15 Jack Hill Ltd伦敦15 Cheez-It 16 Akas Foods Delhi 16 Chex Mix 17美食家。伦敦17 Mighty Munch NULL NULL NULL NULL Salt n Shake
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\`\`\` |