I am still working on w3school. SQL Tutorial is finished. Now I am learning SQL Database part. To construct a database, a database should be created first. Then, under the database, table are created with columns. A column represents an attribute. Basically, the code is like:
CREATE DATABASE database1;
CREATE TABLE table1 (
Col1 datatype (such as INTEGER, VARCHAR, …),
…
);
To simply delete a database or a table, DROP can be used. But if I want to add or delete a column, ALTER should be used. So, when editing under the frame of table, ALTER should always be used.
It is easy to read and understand through reading those instructions. However, I feel like if I do the coding by myself, I would not know which operator to use. I think I will need some practices with real coding.