Updated on 2024-01-23 GMT+08:00

INNER JOIN

Function

This statement is used to join and return the rows that meet the JOIN conditions from two tables as the result set.

Syntax

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SELECT attr_expr_list FROM table_reference
  {JOIN | INNER JOIN} table_reference ON join_condition;

Keyword

JOIN/INNER JOIN: Only the records that meet the JOIN conditions in joined tables will be displayed.

Precautions

  • The to-be-joined table must exist. Otherwise, an error is reported.
  • INNER JOIN can join more than two tables at one query.

Example

To join the course IDs from the student_info and course_info tables and check the mapping between student names and courses, run the following statement:

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SELECT student_info.name, course_info.courseName FROM student_info
  JOIN course_info ON (student_info.courseId = course_info.courseId);