public default String enquoteIdentifier (String identifier, boolean alwaysQuote) throws SQLException

Returns a SQL identifier. If identifier is a simple SQL identifier:

• Return the original value if alwaysQuote is false
• Return a delimited identifier if alwaysQuote is true

If identifier is not a simple SQL identifier, identifier will be enclosed in double quotes if not already present. If the datasource does not support double quotes for delimited identifiers, the identifier should be enclosed by the string returned from DatabaseMetaData.getIdentifierQuoteString. If the datasource does not support delimited identifiers, a SQLFeatureNotSupportedException should be thrown.

A SQLException will be thrown if identifier contains any characters invalid in a delimited identifier or the identifier length is invalid for the datasource.

Parameters:

identifier		a SQL identifier
alwaysQuote		indicates if a simple SQL identifier should be returned as a quoted identifier

Returns:  A simple SQL identifier or a delimited identifier

Exceptions:

SQLException		if identifier is not a valid identifier
SQLFeatureNotSupportedException		if the datasource does not support delimited identifiers
NullPointerException		if identifier is null

Since:  9

@implSpec The default implementation uses the following criteria to determine a valid simple SQL identifier:

• The string is not enclosed in double quotes
• The first character is an alphabetic character from a through z, or from A through Z
• The name only contains alphanumeric characters or the character "_"

The default implementation will throw a SQLException if:

• identifier contains a null character or double quote and is not a simple SQL identifier.
• The length of identifier is less than 1 or greater than 128 characters

Examples of the conversion:

identifier	alwaysQuote	Result
Hello	false	Hello
Hello	true	"Hello"
G'Day	false	"G'Day"
"Bruce Wayne"	false	"Bruce Wayne"
"Bruce Wayne"	true	"Bruce Wayne"
GoodDay$	false	"GoodDay$"
Hello"World	false	SQLException
"Hello"World"	false	SQLException

@implNote JDBC driver implementations may need to provide their own implementation of this method in order to meet the requirements of the underlying datasource.