ALTER TABLE SQL Guide

2 years ago
Emily Johnson
1 minute

The ALTER TABLE statement is used to modify the structure of a table. It can be used to add, delete, or modify columns of a table, as well as modify constraints, indexes, and more.

The specific usage is as follows:

  1. Add a column:
  2. Add a new column with a specified data type to the table.
  3. Delete column:
  4. Remove the column named “column_name” from the table named “table_name”.
  5. Modify column:
  6. Modify the data type of a column in a table.
  7. Change constraints:
  8. Add a constraint named constraint_name to the table table_name with the specified definition.
  9. Update the index.
  10. Add an index named index_name to the column column_name in the table table_name.

Please be cautious when executing the ALTER TABLE statement as it will modify the data in the table, especially in a production environment.

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