how does a user create primary key in database
https://msdn.microsoft.com/en-us/library/khsyc5bb.aspx
https://www.tutorialspoint.com/sql/sql-primary-key.htm
https://docs.microsoft.com/en-us/sql/relational-databases/tables/create-primary-keys
To create a primary key in a database, a user needs to follow these steps:
1. Decide on the table in which you want to create the primary key. It is often related to a unique identifier for each row.
2. Open the database management system (e.g., MySQL, Oracle, Microsoft SQL Server) and connect to the desired database.
3. Determine the data type of the primary key column. Common data types are integer (INT), character (CHAR or VARCHAR), or GUID (Globally Unique Identifier).
4. Create a table by executing a SQL CREATE TABLE statement. For example, in MySQL, you can use the following syntax:
```sql
CREATE TABLE table_name (
column1 data_type PRIMARY KEY,
column2 data_type,
column3 data_type,
...
);
```
Replace `table_name` with the name of your table and `column1` with the chosen column name for the primary key. Make sure to specify the desired data type for the primary key column.
5. Insert data into the table by executing SQL INSERT INTO statements or import data from another source.
The database management system will enforce the uniqueness and non-null values for the primary key column, ensuring each row has a unique identifier.