About
In Sql, an Identifier is a name that identifies an SQL object such as:
- a column
- a table
- a view
Example
"my table name", my_table_name
Definition / Structure
The definition in BNF is:
<SQL language identifier start> ::= <simple Latin letter>
<SQL language identifier> ::= <SQL language identifier start>
[ { <underscore> | <SQL language identifier part> }... ]
<SQL language identifier part> ::=
<simple Latin letter>
| <digit>
It means that a SQL name:
- should start with a simple Latin letter
- followed by characters that are an underscore, a simple Latin letter and a digit.
Note that names may have a space if it's enclosed in some database.
You can find the full definition in the chapter 5.4 of ANSI 1992.
Data Type
Identifier may also refer to a SQL data type that is used to define a column that hold a key value generated.