98 lines
4.8 KiB
Markdown
98 lines
4.8 KiB
Markdown
---
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title: SQL Inner Join Keyword
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---
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## SQL Inner Join Keyword
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### Example of use
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For this guide we'll discuss the SQL (INNER) Joins
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### Join (same as Inner Join)
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The student table will be in the FROM clause so it will be a starting or LEFT table.
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We'll JOIN this to the student contact table or RIGHT table.
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You'll see that all of the students appear that ALSO are in the contact table. As shown in the tables below, studentID 9 is in the student table but NOT in the contact table so won't appear in a join.
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SQL Statement
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```sql
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SELECT a.studentID, a.FullName, a.programOfStudy,
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b.`student-phone-cell`, b.`student-US-zipcode`
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FROM student AS a
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INNER JOIN `student-contact-info` AS b ON a.studentID = b.studentID;
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```
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"Joined" data
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``` text
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+-----------+------------------------+------------------+--------------------+--------------------+
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| studentID | FullName | programOfStudy | student-phone-cell | student-US-zipcode |
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+-----------+------------------------+------------------+--------------------+--------------------+
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| 1 | Monique Davis | Literature | 555-555-5551 | 97111 |
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| 2 | Teri Gutierrez | Programming | 555-555-5552 | 97112 |
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| 3 | Spencer Pautier | Programming | 555-555-5553 | 97113 |
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| 4 | Louis Ramsey | Programming | 555-555-5554 | 97114 |
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| 5 | Alvin Greene | Programming | 555-555-5555 | 97115 |
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| 6 | Sophie Freeman | Programming | 555-555-5556 | 97116 |
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| 7 | Edgar Frank "Ted" Codd | Computer Science | 555-555-5557 | 97117 |
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| 8 | Donald D. Chamberlin | Computer Science | 555-555-5558 | 97118 |
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+-----------+------------------------+------------------+--------------------+--------------------+
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```
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### Complete table listings for reference
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Student table SQL
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```sql
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SELECT a.studentID, a.FullName, sat_score, a.programOfStudy, schoolEmailAdr
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FROM student AS a;
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```
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student or LEFT table
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```text
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+-----------+------------------------+-----------+------------------+------------------------+
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| studentID | FullName | sat_score | programOfStudy | schoolEmailAdr |
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+-----------+------------------------+-----------+------------------+------------------------+
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| 1 | Monique Davis | 400 | Literature | Monique@someSchool.edu |
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| 2 | Teri Gutierrez | 800 | Programming | Teri@someSchool.edu |
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| 3 | Spencer Pautier | 1000 | Programming | Spencer@someSchool.edu |
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| 4 | Louis Ramsey | 1200 | Programming | Louis@someSchool.edu |
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| 5 | Alvin Greene | 1200 | Programming | Alvin@someSchool.edu |
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| 6 | Sophie Freeman | 1200 | Programming | Sophie@someSchool.edu |
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| 7 | Edgar Frank "Ted" Codd | 2400 | Computer Science | Edgar@someSchool.edu |
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| 8 | Donald D. Chamberlin | 2400 | Computer Science | Donald@someSchool.edu |
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| 9 | Raymond F. Boyce | 2400 | Computer Science | Raymond@someSchool.edu |
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+-----------+------------------------+-----------+------------------+------------------------+
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9 rows in set (0.00 sec)
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```sql
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SELECT * FROM `student-contact-info` AS b;
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```
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student contact table or RIGHT table
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``` text
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+-----------+----------------------------------+--------------------+--------------------+
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| studentID | studentEmailAddr | student-phone-cell | student-US-zipcode |
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+-----------+----------------------------------+--------------------+--------------------+
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| 1 | Monique.Davis@freeCodeCamp.org | 555-555-5551 | 97111 |
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| 2 | Teri.Gutierrez@freeCodeCamp.org | 555-555-5552 | 97112 |
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| 3 | Spencer.Pautier@freeCodeCamp.org | 555-555-5553 | 97113 |
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| 4 | Louis.Ramsey@freeCodeCamp.org | 555-555-5554 | 97114 |
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| 5 | Alvin.Green@freeCodeCamp.org | 555-555-5555 | 97115 |
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| 6 | Sophie.Freeman@freeCodeCamp.org | 555-555-5556 | 97116 |
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| 7 | Maximo.Smith@freeCodeCamp.org | 555-555-5557 | 97117 |
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| 8 | Michael.Roach@freeCodeCamp.ort | 555-555-5558 | 97118 |
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+-----------+----------------------------------+--------------------+--------------------+
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8 rows in set (0.00 sec)
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```
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### Conclusion
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As with all of these SQL things there is MUCH MORE to them than what's in this introductory guide.
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I hope this at least gives you enough to get started.
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Please see the manual for your database manager and have fun trying different options yourself.
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