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.

Field Summary

Fields

Modifier and Type	Field and Description
static String	GENERATED_EXPR_ALIAS_PREFIX Prefix for generated column aliases.

Constructor Summary

Constructors

Constructor and Description
SqlUtil()

Method Summary

Modifier and Type	Method and Description
static SqlNode	andExpressions(@Nullable SqlNode node1, SqlNode node2) Returns the AND of two expressions.
static RelNode	attachRelHint(HintStrategyTable hintStrategies, List<RelHint> hints, Hintable rel) Attach the hints to rel with specified hint strategies.
static SqlLiteral	concatenateLiterals(List<SqlLiteral> lits) Concatenates string literals.
static SqlNode	createCall(SqlOperator op, SqlParserPos pos, List<SqlNode> operands) Creates a call to an operator.
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, Predicate<SqlNode> predicate, Predicate<SqlNode> postPredicate) Returns a list of ancestors of predicate within a given SqlNode tree.
static Charset	getCharset(String charsetName) Returns the Java-level Charset based on given SQL-level name.
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 List<RelHint>	getRelHint(HintStrategyTable hintStrategies, @Nullable SqlNodeList sqlHints) Returns an immutable list of RelHint from sql hints, with a given inherit path from the root node.
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	isGeneratedAlias(String alias) Whether the alias is generated by calcite.
static boolean	isLiteral(SqlNode node) Returns whether a node is a literal.
static boolean	isLiteral(SqlNode node, boolean allowCast) 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(@Nullable SqlNode node, boolean allowCast) Returns whether a node represents the NULL value.
static @Nullable SqlOperator	lookupRoutine(SqlOperatorTable opTab, RelDataTypeFactory typeFactory, SqlIdentifier funcName, List<RelDataType> argTypes, @Nullable List<String> argNames, @Nullable SqlFunctionCategory category, SqlSyntax syntax, SqlKind sqlKind, SqlNameMatcher nameMatcher, boolean coerce) Looks up a (possibly overloaded) routine based on name and argument types.
static Iterator<SqlOperator>	lookupSubjectRoutines(SqlOperatorTable opTab, RelDataTypeFactory typeFactory, SqlIdentifier funcName, List<RelDataType> argTypes, @Nullable List<String> argNames, SqlSyntax sqlSyntax, SqlKind sqlKind, @Nullable SqlFunctionCategory category, SqlNameMatcher nameMatcher, boolean coerce) Looks up all subject routines matching the given name and argument types.
static boolean	matchRoutinesByParameterCount(SqlOperatorTable opTab, SqlIdentifier funcName, List<RelDataType> argTypes, SqlFunctionCategory category, SqlNameMatcher nameMatcher) Determines whether there is a routine matching the given name and number of arguments.
static CalciteContextException	newContextException(int line, int col, int endLine, int endCol, org.apache.calcite.runtime.Resources.ExInst<?> e) Wraps an exception with context.
static CalciteContextException	newContextException(SqlParserPos pos, org.apache.calcite.runtime.Resources.ExInst<?> e) Wraps an exception with context.
static CalciteException	newContextException(SqlParserPos pos, org.apache.calcite.runtime.Resources.ExInst<?> e, String inputText) Wraps an exception with context.
static @PolyNull SqlNode	stripAs(@PolyNull SqlNode node) If a node is "AS", returns the underlying expression; otherwise returns the node.
static SqlNodeList	stripListAs(SqlNodeList nodeList) Modifies a list of nodes, removing AS from each if present.
static SqlNodeList	toNodeList(SqlNode[] operands) Converts a SqlNode array to a SqlNodeList.
static @Nullable 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) Deprecated.
static void	unparseFunctionSyntax(SqlOperator operator, SqlWriter writer, SqlCall call, boolean ordered) Unparses a call to an operator that has function syntax.
static void	unparseSqlIdentifierSyntax(SqlWriter writer, SqlIdentifier identifier, boolean asFunctionID) Unparse a SqlIdentifier syntax.
static void	validateCharset(org.apache.calcite.avatica.util.ByteString value, Charset charset) Validate if value can be decoded by given charset.

Methods inherited from class java.lang.Object

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

Field Detail

GENERATED_EXPR_ALIAS_PREFIX

public static final String GENERATED_EXPR_ALIAS_PREFIX

Prefix for generated column aliases. Ends with '$' so that human-written queries are unlikely to accidentally reference the generated name.

See Also:

Constant Field Values

Constructor Detail

SqlUtil

public SqlUtil()

Method Detail

andExpressions

public static SqlNode andExpressions(@Nullable SqlNode node1,
                                     SqlNode node2)

Returns the AND of two expressions.

If node1 is null, returns node2. Flattens if either node is an AND.

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 a SqlNode array to a SqlNodeList.

isNullLiteral

public static boolean isNullLiteral(@Nullable 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,
                                boolean allowCast)

Returns whether a node is a literal.

Examples:

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

Parameters:

node - The node, never null.

allowCast - whether to regard CAST(literal) as a literal

Returns:

Whether the node is a literal

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

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

Deprecated.

unparseFunctionSyntax

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

Unparses a call to an operator that has function syntax.

Parameters:

operator - The operator

writer - Writer

call - List of 0 or more operands

ordered - Whether argument list may end with ORDER BY

unparseSqlIdentifierSyntax

public static void unparseSqlIdentifierSyntax(SqlWriter writer,
                                              SqlIdentifier identifier,
                                              boolean asFunctionID)

Unparse a SqlIdentifier syntax.

Parameters:

writer - Writer

identifier - SqlIdentifier

asFunctionID - Whether this identifier comes from a SqlFunction

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 @Nullable SqlOperator lookupRoutine(SqlOperatorTable opTab,
                                                  RelDataTypeFactory typeFactory,
                                                  SqlIdentifier funcName,
                                                  List<RelDataType> argTypes,
                                                  @Nullable List<String> argNames,
                                                  @Nullable SqlFunctionCategory category,
                                                  SqlSyntax syntax,
                                                  SqlKind sqlKind,
                                                  SqlNameMatcher nameMatcher,
                                                  boolean coerce)

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

Parameters:

opTab - operator table to search

typeFactory - Type factory

funcName - name of function being invoked

argTypes - argument types

argNames - argument names, or null if call by position

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

nameMatcher - Whether to look up the function case-sensitively

coerce - Whether to allow type coercion when do filter routines by parameter types

Returns:

matching routine, or null if none found

See Also:

SQL:1999 Part 2 Section 10.4

lookupSubjectRoutines

public static Iterator<SqlOperator> lookupSubjectRoutines(SqlOperatorTable opTab,
                                                          RelDataTypeFactory typeFactory,
                                                          SqlIdentifier funcName,
                                                          List<RelDataType> argTypes,
                                                          @Nullable List<String> argNames,
                                                          SqlSyntax sqlSyntax,
                                                          SqlKind sqlKind,
                                                          @Nullable SqlFunctionCategory category,
                                                          SqlNameMatcher nameMatcher,
                                                          boolean coerce)

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

Parameters:

opTab - operator table to search

typeFactory - Type factory

funcName - name of function being invoked

argTypes - argument types

argNames - argument names, or null if call by position

sqlSyntax - the SqlSyntax of the SqlOperator being looked up

sqlKind - the SqlKind of the SqlOperator being looked up

category - Category of routine to look up

nameMatcher - Whether to look up the function case-sensitively

coerce - Whether to allow type coercion when do filter routine by parameter types

Returns:

list of matching routines

See Also:

SQL:1999 Part 2 Section 10.4

matchRoutinesByParameterCount

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

Determines whether 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

nameMatcher - Whether to look up the function case-sensitively

Returns:

true if match found

getSelectListItem

public static SqlNode getSelectListItem(SqlNode query,
                                        int i)

Returns the ith select-list item of a query.

deriveAliasFromOrdinal

public static String deriveAliasFromOrdinal(int ordinal)

isGeneratedAlias

public static boolean isGeneratedAlias(String alias)

Whether the alias is generated by calcite.

Parameters:

alias - not null

Returns:

true if alias is generated by calcite, otherwise false

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,
                                                   org.apache.calcite.runtime.Resources.ExInst<?> e,
                                                   String inputText)

Wraps an exception with context.

newContextException

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

Wraps an exception with context.

newContextException

public static CalciteContextException newContextException(int line,
                                                          int col,
                                                          int endLine,
                                                          int endCol,
                                                          org.apache.calcite.runtime.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 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 @Nullable 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

getCharset

public static Charset getCharset(String charsetName)

Returns the Java-level Charset based on given SQL-level name.

Parameters:

charsetName - Sql charset name, must not be null.

Returns:

charset, or default charset if charsetName is null.

Throws:

UnsupportedCharsetException - If no support for the named charset is available in this instance of the Java virtual machine

validateCharset

public static void validateCharset(org.apache.calcite.avatica.util.ByteString value,
                                   Charset charset)

Validate if value can be decoded by given charset.

Parameters:

value - nls string in byte array

charset - charset

Throws:

RuntimeException - If the given value cannot be represented in the given charset

stripAs

public static @PolyNull SqlNode stripAs(@PolyNull SqlNode node)

If a node is "AS", returns the underlying expression; otherwise returns the node. Returns null if and only if the node is null.

stripListAs

public static SqlNodeList stripListAs(SqlNodeList nodeList)

Modifies a list of nodes, removing AS from each if present.

See Also:

stripAs(org.apache.calcite.sql.SqlNode)

getAncestry

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

getRelHint

public static List<RelHint> getRelHint(HintStrategyTable hintStrategies,
                                       @Nullable SqlNodeList sqlHints)

Returns an immutable list of RelHint from sql hints, with a given inherit path from the root node.

The inherit path would be empty list.

Parameters:

hintStrategies - The hint strategies to validate the sql hints

sqlHints - The sql hints nodes

Returns:

the RelHint list

attachRelHint

public static RelNode attachRelHint(HintStrategyTable hintStrategies,
                                    List<RelHint> hints,
                                    Hintable rel)

Attach the hints to rel with specified hint strategies.

Parameters:

hintStrategies - The strategies to filter the hints

hints - The original hints to be attached

Returns:

A copy of rel if there are any hints can be attached given the hint strategies, or the original node if such hints don't exist

createCall

public static SqlNode createCall(SqlOperator op,
                                 SqlParserPos pos,
                                 List<SqlNode> operands)

Creates a call to an operator.

Deals with the fact the AND and OR are binary.