Database layer and code layer id generation strategy

1. Generate GUID in the database

1. SQL Server

Use NEWID() in SQL Server to generate a GUID. The syntax is as follows:

SELECT CHANGE()

2. MySQL

Use UUID in MySQL to generate a GUID, the syntax is as follows:

SELECT UUID();

3. Oracle

Use UUID in Oracle to generate a GUID, the syntax is as follows:

SELECT SYS_GUID() FROM DUAL;

2. Generate GUID in the program

1. DOT.NET C#

Use NewGuid(); in C# to generate it, as follows:

System.Guid.NewGuid().ToString("N"); 32-bit characters

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

System.Guid.NewGuid().ToString("D"); hyphen-delimited 32-bit string

xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

System.Guid.NewGuid().ToString("B"); A 32-bit string in curly braces separated by hyphens

{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}

System.Guid.NewGuid().ToString("P"); 32-bit string in parentheses separated by hyphens

(xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)

2. Java

In the Java language, NewGuid() is no longer used to generate, but UUID is used. The syntax is as follows:

java.util.UUID.randomUUID()