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MySQL JOINs
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MySQL JOINs

MediumSQL · PostgreSQL

Problem

Tell me about the four 'join's in MySQL.

Use the provided left_records and right_records tables to demonstrate the result of each join type. Include matched rows, unmatched rows from both sides, and a small Cartesian-product example.

Output

  1. Columns: join_type, left_record_id, left_label, right_record_id, right_label
  2. Include results for INNER, LEFT, RIGHT, and CROSS joins
  3. For CROSS join results, use left record IDs 1 and 2 with right record IDs 101 and 102
  4. Order by join type in the order INNER, LEFT, RIGHT, CROSS, then by record IDs with NULLs last

Schema

left_records
ColumnTypeDescription
record_idPKINTEGERUnique identifier for a left-side record
join_keyINTEGERValue used to match records between tables
labelVARCHAR(50)Descriptive label for the left-side record
right_records
ColumnTypeDescription
record_idPKINTEGERUnique identifier for a right-side record
join_keyINTEGERValue used to match records between tables
labelVARCHAR(50)Descriptive label for the right-side record
Tablesleft_recordsright_records
Interviewer

Your question is MySQL JOINs. Start with the requirements and the two tables in the Question tab.

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CodePostgreSQL
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