SQL Dialects Reference/Data structure definition/Delimited identifiers
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[edit] Delimited identifiers
A method to somehow escape identifiers (table, column names, etc), so they do not have to obey regular identifier rules, such as not colliding with keywords, having some distinct characters, etc.
| Dialect | Sample | Comment |
|---|---|---|
| Standard | "identifier" |
The SQL standard calls these "delimited identifiers". The SQL standard requires that delimited identifiers are case-sensitive, although not all servers enforce this. |
| DB2 | "identifier" |
Case sensitive per standard and also allows special characters |
| Firebird | "identifier" |
Case sensitive per standard |
| Ingres | "identifier" |
Case sensitivity for delimited identifiers is specified when a database is created. For compliance with ANSI/ISO Entry SQL-92, delimited identifiers must be case sensitive. |
| MSSQL | [identifier]"identifier"[1] |
Case sensitivity is set by a per-database option. |
| MySQL | `identifier`"identifier"[2] |
|
| Oracle | "identifier" |
Oracle's delimited identifiers are case-sensitive, and all regular identifiers are usually in upper case. |
| PostgreSQL | "identifier" |
Case sensitive per standard, or case insensitive without escaping (folded to lowercase not per standard) |
| SQLite | [identifier]"identifier"'identifier'identifier |
Bracketed keywords are always understood as identifiers. Double-quoted keywords are understood as identifiers if previously seen as such, but are otherwise interpreted as string literals. Single-quoted keywords are interpreted as string literals where such are allowed, but otherwise as identifiers. Some keywords may be used as identifiers even when not quoted. |
| Virtuoso | "identifier" |
|
| Linter | "identifier" |
Case sensitive per standard |
Notes:
