Related basics of SQL Server usage

1. Management of tables-naming of tables and columns

• Must start with a letter
• Length cannot exceed 128 characters
• Do not use reserved words for SQL Server
• Only use the following characters A-z,a-z,0-9,$,#,_ and so on

2. Table Management--supported data types

• Character type

Char fixed length, up to 8000 characters (non-Unicode encoding)

CHAR (10) has a length of 10 characters, and less space is used to complement the whole

varchar variable length, Max 8000 characters

varchar (10) Max 10 characters, length varies according to content, can save space

ntext the maximum length of a variable-length character Unicode data is 230~1 (1073741823) characters

Text variable-length character printable Unicode data with a maximum length of 231~1 (2147483647) characters

• Digital type

Bit range 0-1

int range -231-(231-1)

bigint range -262-(262-1)

Float holds decimals, not recommended

Numeric decimal

Related basics of SQL Server usage