Delimited Identifiers
Use
A delimited identifier is an arbitrary sequence of characters (the delimited identifier body ), which is enclosed by double quotes.
< delimited identifier> ::= <double quote> <delimited identifier body> <double quote>.
<delimited identifier body> is a sequence of any character other than the <double quote>
A <regular identifier> is equivalent to a <delimited identifier> if the <delimited identifier body> of the <delimited identifier> is the <regularidentifier> with every lower case letter replaced with its equivalent upper case letter.The following table gives an overview which identifiers are equivalent.
|
Hugo |
hugo |
HUGO |
"Hugo" |
"hugo" |
"HUGO" |
|
|---|---|---|---|---|---|---|
|
Hugo |
equivalent |
equivalent |
equivalent |
different |
different |
equivalent |
|
hugo |
equivalent |
equivalent |
equivalent |
different |
different |
equivalent |
|
HUGO |
equivalent |
equivalent |
equivalent |
different |
different |
equivalent |
|
"Hugo" |
different |
different |
different |
equivalent |
different |
different |
|
"hugo" |
different |
different |
different |
different |
equivalent |
different |
|
"HUGO" |
equivalent |
equivalent |
equivalent |
different |
different |
equivalent |
Regular Identifiers are interpreted in upper case. Delimited Identifiers are case sensitive.
Example
SELECT "col" FROM "dbtab" WHERE "DBTAB"."COL" = 'abc'
Delimited Identifiers . In this example, "col" and "COL" denominate different columns, "dbtab" and "DBTAB" denominate different tables.
SELECT col FROM dbtab WHERE "dbtab"."COL" = 'abc'
Regular and Delimited Identifiers. Here, col and "COL" denominate one and the same column, dbtab and " dbtab " denominate different tables.
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