uk.ac.starlink.vo

Class AdqlSyntax

java.lang.Object

uk.ac.starlink.table.jdbc.SqlSyntax

uk.ac.starlink.vo.AdqlSyntax

public class AdqlSyntax
extends SqlSyntax

SqlSyntax instance for the ADQL 2.* grammar.

Instances INSTANCE20 and INSTANCE21 are currently provided for ADQL versions 2.0 and 2.1 respectively. However the differences between these are very small (just a few extra reserved words for V2.1) so the method getInstance() is usually an appropriate way to obtain an instance of this class.

Since:

22 Jun 2011

Author:

Mark Taylor

See Also:

ADQL 2.0 Standard, ADQL 2.0 BNF

Field Summary

Fields

Modifier and Type	Field and Description
static String[]	ADQL_RESERVED ADQL reserved words additional to the SQL92 set, taken from the ADQL standard.
static String[]	ADQL21_RESERVED Additional reserved words from ADQL 2.1 section 2.1.4.
static AdqlSyntax	INSTANCE20 Instance for V2.0 of the ADQL standard.
static AdqlSyntax	INSTANCE21 Instance for V2.1 of the ADQL standard.

Fields inherited from class uk.ac.starlink.table.jdbc.SqlSyntax

SQL92_IDENTIFIER_REGEX, SQL92_RESERVED

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AdqlSyntax(AdqlVersion adqlVersion) Protected constructor to signal that static instances or methods should usually be used to obtain an instance.

Method Summary

Modifier and Type	Method and Description
String	characterLiteral(String txt) Returns ADQL text representing a character literal.
String[]	getCatalogSchemaTable(String tableName) Takes an ADQL <table_name> token and returns a 3-element array giving the catalog, schema and table (delimited or regular) identifiers.
static AdqlSyntax	getInstance() Returns an instance of this class.
boolean	isAdqlColumnName(String token) Indicates whether the given token matches the ADQL <column_name> production.
boolean	isAdqlDelimitedIdentifier(String token) Indicates whether the given token matches the ADQL <delimited_identifier> production.
boolean	isAdqlTableName(String token) Indicates whether the given token matches the ADQL <table_name> production.
String	unquote(String identifier) Takes a regular-or-delimited-identifier and returns its raw form.

Methods inherited from class uk.ac.starlink.table.jdbc.SqlSyntax

getParanoidReservedWords, getReservedWords, isIdentifier, isReserved, quote, quoteIfNecessary

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ADQL_RESERVED

public static final String[] ADQL_RESERVED

ADQL reserved words additional to the SQL92 set, taken from the ADQL standard.

ADQL21_RESERVED

public static final String[] ADQL21_RESERVED

Additional reserved words from ADQL 2.1 section 2.1.4.

INSTANCE20

public static final AdqlSyntax INSTANCE20

Instance for V2.0 of the ADQL standard.

INSTANCE21

public static final AdqlSyntax INSTANCE21

Instance for V2.1 of the ADQL standard.

Constructor Detail

AdqlSyntax

protected AdqlSyntax(AdqlVersion adqlVersion)

Protected constructor to signal that static instances or methods should usually be used to obtain an instance.

Parameters:

adqlVersion - version of the ADQL standard

Method Detail

isAdqlDelimitedIdentifier

public boolean isAdqlDelimitedIdentifier(String token)

Indicates whether the given token matches the ADQL <delimited_identifier> production.

Parameters:

token - token to test

Returns:

true iff token is a delimited_identifier

isAdqlColumnName

public boolean isAdqlColumnName(String token)

Indicates whether the given token matches the ADQL <column_name> production.

Parameters:

token - token to test

Returns:

true iff token is a column_name

isAdqlTableName

public boolean isAdqlTableName(String token)

Indicates whether the given token matches the ADQL <table_name> production.

Parameters:

token - token to test

Returns:

true iff token is a table_name

getCatalogSchemaTable

public String[] getCatalogSchemaTable(String tableName)

Takes an ADQL <table_name> token and returns a 3-element array giving the catalog, schema and table (delimited or regular) identifiers.

For a non-null result, the input token must match the ADQL <table_name> production, which is the same rule that TAP_SCHEMA table_name columns must follow, which roughly means it's of the form [catalog.[schema.[table]]]. Either catalog alone, or both catalog and schema, may be null. The return value is either a three-element array (with 1, 2 or 3 non-null elements) in case of a legal table_name input, or null in case of an illegal table_name input.

Parameters:

tableName - table_name string

Returns:

3-element array giving (catalog, schema, table) identifiers, or null for parse failure

unquote

public String unquote(String identifier)

Takes a regular-or-delimited-identifier and returns its raw form. For a regular identifier, the output is the same as the input.

Parameters:

identifier - regular or delimited identifier, or null

Returns:

identifier with no surrounding quotes or other escaping, or null for null input

characterLiteral

public String characterLiteral(String txt)

Returns ADQL text representing a character literal. This quotes the supplied string by surrounding it with single quotes, escaping any internal single quote characters appropriately.

Parameters:

txt - raw text

Returns:

character literal suitable for insertion into ADQL text

getInstance

public static AdqlSyntax getInstance()

Returns an instance of this class. This currently returns the instance representing ADQL 2.1. There is very little difference between this and the ADQL 2.0 instance, just a few extra reserved words, so it's suitable for general use in most cases.

Returns:

AdqlSyntax instance