drop in sql code example

Example 1: how remove column in mysql

ALTER TABLE "table_name" DROP "column_name";

Example 2: drop table

DROP TABLE table_name;

Example 3: sql drop table

-- Drop, but no space gain
DROP TABLE table_name;
-- Really frees space (Oracle)
DROP TABLE table_name PURGE;

Example 4: delete and drop in sql

DELETE -
-DML COMMAND
-Delete Rows from the table one by one
-We can use where clause with Delete to delete single row
-Delete is slower than truncate
-ROLLBACK is possible with DELETE

DROP-
-DDL COMMAND
-Delete the entire structure or schema
-We can't use where clause with drop
-Drop is slower than DELETE & TRUNCATE
-ROLLBACK IS NOT POSSIBLE WITH DROP

TRUNCATE-
-DDL COMMAND
-Truncate deletes rows at a one goal
-We can't use where clause with Truncate
-Truncate faster than both DELETE & DROP
-Rollback is not possible with Truncate

Example 5: delete table

DROP TABLE table_name;