ALTER TABLE

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Published May 7, 2021Updated Jun 25, 2022
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The ALTER TABLE command adds, deletes, modifies, or changes the data type of a column in a table.

Code Example

Beginning table:

student_id name address last_terms_grades overall_gpa
10001 Tim 123 R Ave 2.4 3.1
10002 Amy 789 T St 3.2 3.8
ALTER TABLE students
ADD exam_grade INT(3);

After ADDing the new column exam_grade:

student_id name address last_terms_grades overall_gpa exam_grade
10001 Tim 123 R Ave 2.4 3.1 null
10002 Amy 789 T St 3.2 3.8 null
ALTER TABLE students
DROP COLUMN last_terms_grades;

After DROPing the column last_terms_grades:

student_id name address overall_gpa exam_grade
10001 Tim 123 R Ave 3.1 null
10002 Amy 789 T St 3.8 null

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