1.USE <DatabaseName> //Select database
Example: USE [master] //master is the system default database
2. When the field or table name is the same as the reserved word or keyword, it needs to be added.
3. COMPATIBILITY_LEVEL is used to set the compatibility level of SQL Server.
例：ALTER DATABASE DatabaseName SET COMPATIBILITY_LEVEL = 100
ps: 80, 90 and 100 represent SQL Server 2000, SQL Server 2005 and SQL Server 2008 respectively.
4. FULLTEXTSERVICEPROPERTY ( property ) -- Returns information about the properties of the full-text engine.
5.DECLARE @var_name var_type //Declare variables and initialize variables separately
SET @var_name = xx
6. Although all Transact-SQL statements are valid within a BEGIN...END block, some Transact-SQL statements should not be grouped in the same batch or statement block.
7. Before calling EXECUTE with a string, validate the string. Never execute commands constructed from unvalidated user input.
8. When storing strings in variables, sometimes N is added before the strings, where N represents the Unicode universal code.
In the unicode character set, a character is two bytes . The encoding methods are UTF-8, UTF-16, UTF-32.
Microsoft's official website has online documentation for Transact-SQL, which can be said to be very friendly.
https://docs.microsoft.com/zh-cn/sql/t-sql/language-reference