Difference between table and schema in the database: tableschema

Difference between table and schema in the database: tableschema

What is Database, Schema, Table, column, row, and User?

We can regard the Database as a big warehouse. The Warehouse is divided into many rooms. The Schema is the room, and a Schema represents a room.

A Table can be seen as a bed in each Schema. A Table is placed in every room and cannot be placed outside the room. It is not a homeless thing to go to bed at night.

Then many items can be placed on the bed, just like many columns and rows can be placed on the Table. The basic unit for storing data in the database is Table. In reality, the basic unit for storing items in each warehouse is the bed.

The User is the master of each Schema (so the Schema contains objects rather than users). In fact, the User corresponds to the database (that is, the User is the master of each corresponding database ).

The right to operate databases (warehouses) must have the right to operate each Schema (room) in the database. That is to say, the User mapped to each database has the key for each Schema (room,

In other words, if he is the owner of a warehouse, his right to use the warehouse and everything in the warehouse is his (including the room), and he has full right to operate. The system administrator can also

Assign specific permissions, that is, what he can do in a room, whether he can Only view (Read-Only), or have control (R/W) as the master ), this depends on the corresponding User.

Role.