This MySQL Drop Table lesson is for a beginner. Read the short notes, run each example, then change one name or number and run it again.
DROP TABLE deletes the table itself, including its rows and its structure.
DROP DATABASE deletes every table in that database. Both need a deliberate check of the name.
Example 1: Start here
DROP TABLE batch cannot be rolled back on a typical MySQL setup.
tables = {"learner": [{"id": 1}], "batch": []} # a dictionary; each key has one value
del tables["batch"] # remove this name
print(sorted(tables)) # a new list, sorted
Example 2: Filter the rows
MySQL Drop Table is easier to see as a list of records. The filter keeps every row whose seats value is at least 10.
rows = [{"topic": "MySQL Drop Table", "seats": 33}, {"topic": "SQL", "seats": 12}] # a list; the values stay in this order
print([row["topic"] for row in rows if row["seats"] >= 10]) # keep the items that pass the test
Example 3: Update one field
An update changes one field and leaves the rest of the record alone. On a database you would run an UPDATE or an update_one for the same change.
row = {"topic": "MySQL Drop Table", "seats": 33} # a dictionary; each key has one value
row["seats"] = row["seats"] + 1 # change this one field
print(row)
Example 4: Count the matches
Counting matches is the idea behind COUNT(*). Here the number 33 appears twice.
rows = [33, 4, 33] # a list; the values stay in this order
print(sum(1 for value in rows if value == 33)) # keep the items that pass the test
DROP TABLE batch cannot be rolled back on a typical MySQL setup.
