11
votes
2answers
1k views

Fastest way to change a 600GB table indexed key datatype from INT to BIGINT

I need to change a datatype from INT to BIGINT in a 600GB MySQL table. The column has a unique index. I might be good with unsigned INT, but I assume changing to that or BIGINT will be pretty much ...
3
votes
2answers
3k views

How to make a trigger that will compare input with a value of other table?

I had made two tables with the following fields: TABLE 1: "Bookings" FIELD: "fk_flight_number" FIELD: "date_of_reservation" TABLE 2: "Flights" FIELD: "flight_number" FIELD: ...
6
votes
1answer
12k views

What happens when you modify (reduce) a column's length?

Lets say I have two columns of type NUMBER (without precision, and scale) and VARCHAR(300). I saw that these columns are way too large for my data, so I want to modify them to NUMBER(11) and ...
5
votes
4answers
14k views

Add a new Column and define its position in a table

I have Table A with 5 columns: TableA -- Name Tel Email Address I want to add a new column (mobile) in between Tel & Email: TableA -- Name Tel Mobile Email Address If I use ALTER TABLE ...
2
votes
1answer
1k views

Default values in SQLite3

When I created the table structure of my SQLite database, I provided a DEFAULT value which is used when no value is provided by the user. Now, because the application code changed, I need to modify ...