Insert the same fixed value into multiple rows

Inserting vs. updating data

To clarify, the process to insert a fixed value into multiple rows differs from updating existing rows. INSERT is for new rows:

INSERT INTO best_table (great_column)
VALUES ('good_story_mate'); -- Gives birth to a new row with a good story.
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For existing rows, you use UPDATE instead:

UPDATE best_table
SET great_column = 'better_story'; -- This makes all stories better. You're welcome!
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Fine-tune the updates with WHERE clause:

UPDATE best_table
SET great_column = 'better_story'
WHERE condition; -- Unleashes the 'better_story' only on rows matching the condition.
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Before making changes to your production databases, always test on a subset and maintain a backup. Real heroes don't forget about possible constraints or triggers.

Dealing with special values and pitfalls

Handling NULL values

With NULL values, you need to handle them separately in a WHERE clause:

UPDATE best_table
SET great_column = 'better_story'
WHERE great_column IS NULL; -- NULLs didn't believe in stories until today.
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The secrets of quoting

Single quotes are for string literals in SQL, whereas double quotes are used for identifiers like columns and tables - they like to feel special:

UPDATE best_table
SET great_column = 'better_story'
WHERE "other_column" = "identifier"; -- Oh, look! Single quotes working together with double quotes.
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Constraints and semantics

Beware of the schema goblins or database demons i.e., constraints or triggers, which could impact the result of the updates. Knowledge is power, use it wisely.

Efficient operations

Updating/inserting fixed values into multiple rows can be a heavy task for your database. Plan these during non-peak hours. Batch your work for maximum efficiency.

Advanced database wizardry

Bulk insert via SELECT

For inserting multiple rows, consider a SELECT within an INSERT:

INSERT INTO my_table (my_column)
SELECT 'tale'
FROM another_table
WHERE condition; -- Rogue 'tale' being spread across multiple rows. It's contagious!
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Working with default values

Create a DEFAULT constraint for frequent insertions:

ALTER TABLE my_table
ALTER COLUMN my_column SET DEFAULT 'tale';
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Now, you automatically get a 'tale' with each insert.

Safety with parameterization

Prevent SQL injection and improve code maintainability with parameterization.