Identifiers are used to identify or name objects like tables, columns, schemas, and indexes.
There are two kinds of identifiers, regular and delimited.
Regular identifiers are:
Not delimited by double quotes
Case insensitive
Comprised of only letters, digits and the underscore character
Delimited identifiers are:
Delimited by double quotes
Case sensitive
Comprised of letters, digits, and any of the following characters: % & ' ( ) * + , - . / : ; < = > ? [ ]
Use a delimited identifier if your object:
Contain blanks
Does not start with a letter
Is identical to a keyword
Is case-sensitive
Contains any of the following characters: % & ' ( ) * + , - . / : ; < = > ? [ ]
Examples
|
Incorrect Indetifier |
Correct Identifier |
Explanation |
|
create view table as select TABLE_NAME,TABLE_TYPE from information_schema.tables where table_schema=USER; |
create view "table" as select TABLE_NAME,TABLE_TYPE from information_schema.tables where table_schema=USER; |
Table is a keyword and can not be used as a regular identifier. If it is used as a delimited identifier, it can specify a view name.
|
|
select col1-1 from tab1; |
select "col1-1" from tab1; |
col1-1 is a numeric operation in select list and can not be used as a regular identifier. If it is used as a delimited identifier, it can specify a column name.
|
CONNX can handle identifiers of up to 128 characters.