org.apache.calcite.sql

Class SqlUtil

java.lang.Object

org.apache.calcite.sql.SqlUtil

public abstract class SqlUtil
extends Object

Contains utility functions related to SQL parsing, all static.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SqlUtil.DatabaseMetaDataInvocationHandler Handles particular DatabaseMetaData methods; invocations of other methods will fall through to the base class, BarfingInvocationHandler, which will throw an error.

Constructor Summary

Constructors

Constructor and Description
SqlUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static SqlLiteral	concatenateLiterals(List<SqlLiteral> lits) Concatenates string literals.
static RelDataType	createNlsStringType(RelDataTypeFactory typeFactory, NlsString str) Creates the type of an NlsString.
static String	deriveAliasFromOrdinal(int ordinal)
static String	getAliasedSignature(SqlOperator op, String opName, List<?> typeList) Constructs an operator signature from a type list, substituting an alias for the operator name.
static com.google.common.collect.ImmutableList<SqlNode>	getAncestry(SqlNode root, com.google.common.base.Predicate<SqlNode> predicate, com.google.common.base.Predicate<SqlNode> postPredicate) Returns a list of ancestors of predicate within a given SqlNode tree.
static SqlNode	getFromNode(SqlSelect query, int ordinal) Returns the nth (0-based) input to a join expression.
static String	getOperatorSignature(SqlOperator op, List<?> typeList) Constructs an operator signature from a type list.
static SqlNode	getSelectListItem(SqlNode query, int i) Returns the ith select-list item of a query.
static boolean	isCallTo(SqlNode node, SqlOperator operator) Returns whether a node is a call to a given operator.
static boolean	isLiteral(SqlNode node) Returns whether a node is a literal.
static boolean	isLiteralChain(SqlNode node) Returns whether a node is a literal chain which is used to represent a continued string literal.
static boolean	isNull(SqlNode node) Returns whether a node represents the NULL value or a series of nested CAST(NULL AS type) calls.
static boolean	isNullLiteral(SqlNode node, boolean allowCast) Returns whether a node represents the NULL value.
static SqlFunction	lookupRoutine(SqlOperatorTable opTab, SqlIdentifier funcName, List<RelDataType> argTypes, SqlFunctionCategory category) Looks up a (possibly overloaded) routine based on name and argument types.
static List<SqlFunction>	lookupSubjectRoutines(SqlOperatorTable opTab, SqlIdentifier funcName, List<RelDataType> argTypes, SqlFunctionCategory category) Looks up all subject routines matching the given name and argument types.
static SqlCall	makeCall(SqlOperatorTable opTab, SqlIdentifier id) If an identifier is a legitimate call to a function which has no arguments and requires no parentheses (for example "CURRENT_USER"), returns a call to that function, otherwise returns null.
static boolean	matchRoutinesByParameterCount(SqlOperatorTable opTab, SqlIdentifier funcName, List<RelDataType> argTypes, SqlFunctionCategory category) Determine if there is a routine matching the given name and number of arguments.
static CalciteContextException	newContextException(int line, int col, int endLine, int endCol, Resources.ExInst<?> e) Wraps an exception with context.
static CalciteContextException	newContextException(SqlParserPos pos, Resources.ExInst<?> e) Wraps an exception with context.
static CalciteException	newContextException(SqlParserPos pos, Resources.ExInst<?> e, String inputText) Wraps an exception with context.
static SqlNode	stripAs(SqlNode node) If a node is "AS", returns the underlying expression; otherwise returns the node.
static SqlNodeList	toNodeList(SqlNode[] operands) Converts an SqlNode array to a SqlNodeList
static String	translateCharacterSetName(String name) Translates a character set name from a SQL-level name into a Java-level name.
static void	unparseBinarySyntax(SqlOperator operator, SqlCall call, SqlWriter writer, int leftPrec, int rightPrec)
static void	unparseFunctionSyntax(SqlOperator operator, SqlWriter writer, SqlCall call) Unparses a call to an operator which has function syntax.

Methods inherited from class java.lang.Object

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

Constructor Detail

SqlUtil

public SqlUtil()

Method Detail

getFromNode

public static SqlNode getFromNode(SqlSelect query,
                  int ordinal)

Returns the nth (0-based) input to a join expression.

toNodeList

public static SqlNodeList toNodeList(SqlNode[] operands)

Converts an SqlNode array to a SqlNodeList

isNullLiteral

public static boolean isNullLiteral(SqlNode node,
                    boolean allowCast)

Returns whether a node represents the NULL value.

Examples:

• For SqlLiteral Unknown, returns false.
• For CAST(NULL AS type), returns true if allowCast is true, false otherwise.
• For CAST(CAST(NULL AS type) AS type)), returns false.

isNull

public static boolean isNull(SqlNode node)

Returns whether a node represents the NULL value or a series of nested CAST(NULL AS type) calls. For example: isNull(CAST(CAST(NULL as INTEGER) AS VARCHAR(1))) returns true.

isLiteral

public static boolean isLiteral(SqlNode node)

Returns whether a node is a literal.

Many constructs which require literals also accept CAST(NULL AS type). This method does not accept casts, so you should call isNullLiteral(org.apache.calcite.sql.SqlNode, boolean) first.

Parameters:

node - The node, never null.

Returns:

Whether the node is a literal

isLiteralChain

public static boolean isLiteralChain(SqlNode node)

Returns whether a node is a literal chain which is used to represent a continued string literal.

Parameters:

node - The node, never null.

Returns:

Whether the node is a literal chain

unparseFunctionSyntax

public static void unparseFunctionSyntax(SqlOperator operator,
                         SqlWriter writer,
                         SqlCall call)

Unparses a call to an operator which has function syntax.

Parameters:

operator - The operator

writer - Writer

call - List of 0 or more operands

unparseBinarySyntax

public static void unparseBinarySyntax(SqlOperator operator,
                       SqlCall call,
                       SqlWriter writer,
                       int leftPrec,
                       int rightPrec)

concatenateLiterals

public static SqlLiteral concatenateLiterals(List<SqlLiteral> lits)

Concatenates string literals.

This method takes an array of arguments, since pairwise concatenation means too much string copying.

Parameters:

lits - an array of SqlLiteral, not empty, all of the same class

Returns:

a new SqlLiteral, of that same class, whose value is the string concatenation of the values of the literals

Throws:

ClassCastException - if the lits are not homogeneous.

ArrayIndexOutOfBoundsException - if lits is an empty array.

lookupRoutine

public static SqlFunction lookupRoutine(SqlOperatorTable opTab,
                        SqlIdentifier funcName,
                        List<RelDataType> argTypes,
                        SqlFunctionCategory category)

Looks up a (possibly overloaded) routine based on name and argument types.

Parameters:

opTab - operator table to search

funcName - name of function being invoked

argTypes - argument types

category - whether a function or a procedure. (If a procedure is being invoked, the overload rules are simpler.)

Returns:

matching routine, or null if none found

lookupSubjectRoutines

public static List<SqlFunction> lookupSubjectRoutines(SqlOperatorTable opTab,
                                      SqlIdentifier funcName,
                                      List<RelDataType> argTypes,
                                      SqlFunctionCategory category)

Looks up all subject routines matching the given name and argument types.

Parameters:

opTab - operator table to search

funcName - name of function being invoked

argTypes - argument types

category - category of routine to look up

Returns:

list of matching routines

matchRoutinesByParameterCount

public static boolean matchRoutinesByParameterCount(SqlOperatorTable opTab,
                                    SqlIdentifier funcName,
                                    List<RelDataType> argTypes,
                                    SqlFunctionCategory category)

Determine if there is a routine matching the given name and number of arguments.

Parameters:

opTab - operator table to search

funcName - name of function being invoked

argTypes - argument types

category - category of routine to look up

Returns:

true if match found

getSelectListItem

public static SqlNode getSelectListItem(SqlNode query,
                        int i)

Returns the ith select-list item of a query.

makeCall

public static SqlCall makeCall(SqlOperatorTable opTab,
               SqlIdentifier id)

If an identifier is a legitimate call to a function which has no arguments and requires no parentheses (for example "CURRENT_USER"), returns a call to that function, otherwise returns null.

deriveAliasFromOrdinal

public static String deriveAliasFromOrdinal(int ordinal)

getOperatorSignature

public static String getOperatorSignature(SqlOperator op,
                          List<?> typeList)

Constructs an operator signature from a type list.

Parameters:

op - operator

typeList - list of types to use for operands. Types may be represented as String, SqlTypeFamily, or any object with a valid Object.toString() method.

Returns:

constructed signature

getAliasedSignature

public static String getAliasedSignature(SqlOperator op,
                         String opName,
                         List<?> typeList)

Constructs an operator signature from a type list, substituting an alias for the operator name.

Parameters:

op - operator

opName - name to use for operator

typeList - list of SqlTypeName or String to use for operands

Returns:

constructed signature

newContextException

public static CalciteException newContextException(SqlParserPos pos,
                                   Resources.ExInst<?> e,
                                   String inputText)

Wraps an exception with context.

newContextException

public static CalciteContextException newContextException(SqlParserPos pos,
                                          Resources.ExInst<?> e)

Wraps an exception with context.

newContextException

public static CalciteContextException newContextException(int line,
                                          int col,
                                          int endLine,
                                          int endCol,
                                          Resources.ExInst<?> e)

Wraps an exception with context.

isCallTo

public static boolean isCallTo(SqlNode node,
               SqlOperator operator)

Returns whether a node is a call to a given operator.

createNlsStringType

public static RelDataType createNlsStringType(RelDataTypeFactory typeFactory,
                              NlsString str)

Creates the type of an NlsString.

The type inherits the The NlsString's Charset and SqlCollation, if they are set, otherwise it gets the system defaults.

Parameters:

typeFactory - Type factory

str - String

Returns:

Type, including collation and charset

translateCharacterSetName

public static String translateCharacterSetName(String name)

Translates a character set name from a SQL-level name into a Java-level name.

Parameters:

name - SQL-level name

Returns:

Java-level name, or null if SQL-level name is unknown

stripAs

public static SqlNode stripAs(SqlNode node)

If a node is "AS", returns the underlying expression; otherwise returns the node.

getAncestry

public static com.google.common.collect.ImmutableList<SqlNode> getAncestry(SqlNode root,
                                                           com.google.common.base.Predicate<SqlNode> predicate,
                                                           com.google.common.base.Predicate<SqlNode> postPredicate)

Returns a list of ancestors of predicate within a given SqlNode tree.

The first element of the list is root, and the last is the node that matched predicate. Throws if no node matches.