ExplainOrSelectStatement
::= ( 'EXPLAIN' ( '(' CharacterConstant ')' )? )? SelectStatement

CharacterConstant
::= S_CHAR_LITERAL
| S_PARAMETER

SelectStatement
::= SelectWithOrder ';'?

SelectWithOrder
::= QueryExpressionBody OrderByClause? LimitClause?

QueryExpressionBody
::= QueryTerm ( ( 'UNION' | 'EXCEPT' | 'MINUS' ) ( 'ALL' | 'DISTINCT' )? QueryTerm )*

QueryTerm
::= QueryPrimary ( 'INTERSECT' ( 'ALL' | 'DISTINCT' )? QueryPrimary )*

QueryPrimary
::= SelectWithoutOrder
| '(' QueryExpressionBody ')'

SelectWithoutOrder
::= 'SELECT' ( 'ALL' | 'DISTINCT' )? SelectList FromClause WhereClause? GroupByClause? HavingClause?

SelectList
::= SelectItem ( ',' SelectItem )*

SelectItem
::= '*'
| SelectStar
| SqlSimpleExpression Alias?

SelectStar
::= ObjectName '.' ( ObjectName '.' )? '*'

ObjectName
::= S_IDENTIFIER
| S_QUOTED_IDENTIFIER

SqlSimpleExpression
::= SqlMultiplicativeExpression ( ( '+' | '-' | '||' ) SqlMultiplicativeExpression )*

SqlMultiplicativeExpression
::= SqlExponentExpression ( ( '*' | '/' | '%' ) SqlExponentExpression )*

SqlExponentExpression
::= SqlUnaryExpression ( '**' SqlUnaryExpression )*

SqlUnaryExpression
::= ( '+' | '-' )? SqlPrimaryExpression

SqlPrimaryExpression
::= '(' SqlExpression ')'
| Constant
| FunctionCall
| ( AggregateFunctionCall | GenericFunctionCall ) WindowSpecification?
| GroupingOperation
| WindowFunctionCall
| ObjectName ( '.' ( GenericFunctionCall WindowSpecification? | ObjectName ( '.' ObjectName )? ArrayElementReference? ) | ArrayElementReference )?
| ArrayValueConstructor

SqlExpression
::= SqlAndExpression ( 'OR' SqlAndExpression )*

SqlAndExpression
::= SqlUnaryLogicalExpression ( 'AND' SqlUnaryLogicalExpression )*

SqlUnaryLogicalExpression
::= 'NOT'? SqlRelationalExpression

SqlRelationalExpression
::= ( '(' SqlExpressionList ')' | SqlSimpleExpression ) ( SqlRelationalOperatorExpression | SqlInClause | SqlBetweenClause | SqlLikeClause | IsNullClause )?

SqlExpressionList
::= SqlExpression ( ',' SqlExpression )*

SqlRelationalOperatorExpression
::= Relop ( '(' QueryExpressionBody ')' | SqlSimpleExpression )

Relop ::= '='
| '!='
| '#'
| '<>'
| '>'
| '>='
| '<'
| '<='

SqlInClause
::= 'NOT'? 'IN' '(' SqlExpressionList ')'

SqlBetweenClause
::= 'NOT'? 'BETWEEN' SqlSimpleExpression 'AND' SqlSimpleExpression

SqlLikeClause
::= 'NOT'? 'LIKE' SqlSimpleExpression

IsNullClause
::= 'IS' 'NOT'? 'NULL'

Constant ::= 'NULL'
| ( '+' | '-' )? S_NUMBER
| S_CHAR_LITERAL
| 'TRUE'
| 'FALSE'
| S_PARAMETER

FunctionCall
::= ( ( ( 'ABS' | 'CEIL' | 'CEILING' | 'CHAR_LENGTH' | 'CHARACTER_LENGTH' | 'EXP' | 'FLOOR' | 'LN' | 'LOWER' | 'SQRT' | 'UPPER' ) '(' | ( 'MOD' | 'POWER' ) '(' SqlExpression ',' | 'TRIM' '(' ( ( 'LEADING' | 'TRAILING' | 'BOTH' )? SqlExpression? 'FROM' )? | 'SUBSTRING' '(' SqlExpression 'FROM' ( SqlExpression 'FOR' )? | ( 'ROUND' | 'TRUNC' | 'TRUNCATE' ) '(' ( SqlExpression ',' )? ) SqlExpression | 'CAST' '(' SqlExpression 'AS' CastableDataTypeDeclaration ) ')'
| 'CASE' ( SimpleCaseCall | BooleanCaseCall )

CastableDataTypeDeclaration
::= ( 'BIG_DECIMAL' | 'BYTE' | 'INTEGER' | 'FLOAT' | 'LONG' | 'SHORT' | 'DOUBLE' | 'CHARACTER' | 'STRING' | 'SQL_DATE' | 'SQL_TIMESTAMP' | 'SQL_TIME' | 'DATE' | 'BOOLEAN' | 'BLOB' | 'CLOB' | 'REF' | 'STRUCT' | 'UNKNOWN' | UserDefinedType ) 'ARRAY'?

UserDefinedType
::= S_IDENTIFIER ( '.' S_IDENTIFIER )?

SimpleCaseCall
::= SqlSimpleExpression ( 'WHEN' SqlSimpleExpression 'THEN' SqlSimpleExpression )+ ( 'ELSE' SqlSimpleExpression )? 'END'

BooleanCaseCall
::= ( 'WHEN' SqlExpression 'THEN' SqlSimpleExpression )+ ( 'ELSE' SqlSimpleExpression )? 'END'

AggregateFunctionCall
::= ( ( 'AVG' | 'MAX' | 'MIN' | 'STDDEV_POP' | 'STDDEV' | 'STDDEV_SAMP' | 'SUM' | 'VAR_POP' | 'VARIANCE' | 'VAR_SAMP' ) '(' ( ( 'ALL' | 'DISTINCT' ) SourceField | SqlExpression ) | 'COUNT' '(' ( '*' | ( 'ALL' | 'DISTINCT' ) SourceField | SqlExpression ) | ( 'CORR' | 'COVAR_POP' | 'COVAR_SAMP' | 'COVAR' | 'REGR_INTERCEPT' | 'REGR_R2' | 'REGR_SLOPE' ) '(' ( SqlExpression | SourceField ) ',' ( SqlExpression | SourceField ) ) ')'

SourceField
::= ObjectName ( '.' ObjectName ( '.' ObjectName )? )?

GenericFunctionCall
::= ObjectName '(' SqlExpressionList? ( ';' ConstantList )? ')'

ConstantList
::= Constant ( ',' Constant )*

WindowSpecification
::= 'OVER' '(' ( 'PARTITION' 'BY' SqlExpressionList )? OrderByClause? WindowFrameClause? ')'

OrderByClause
::= 'ORDER' 'BY' SqlExpression ( 'ASC' | 'DESC' )? ( 'NULLS' ( 'FIRST' | 'LAST' ) )? ( ',' SqlExpression ( 'ASC' | 'DESC' )? ( 'NULLS' ( 'FIRST' | 'LAST' ) )? )*

WindowFrameClause
::= ( 'ROWS' | 'RANGE' ) ( WindowFrameStart | 'BETWEEN' WindowFrameBound 'AND' WindowFrameBound )

WindowFrameStart
::= ( 'UNBOUNDED' | FrameBound ) 'PRECEDING'
| 'CURRENT' 'ROW'

FrameBound
::= S_NUMBER
| S_PARAMETER

WindowFrameBound
::= ( 'UNBOUNDED' | FrameBound ) 'FOLLOWING'
| WindowFrameStart

GroupingOperation
::= 'GROUPING' '(' SqlExpressionList ')'

WindowFunctionCall
::= ( ( 'RANK' | 'DENSE_RANK' | 'PERCENT_RANK' | 'CUME_DIST' | 'ROW_NUMBER' ) '(' | 'NTILE' '(' LongConstant | ( 'LEAD' | 'LAG' ) '(' ( SqlExpression | SourceField ) ( ',' IntegerConstant ( ',' Constant )? )? | ( ( 'FIRST_VALUE' | 'LAST_VALUE' ) '(' ( SqlExpression | SourceField ) | 'NTH_VALUE' '(' ( SqlExpression | SourceField ) ',' IntegerConstant ) ( ',' Constant )? ) ')' WindowSpecification

LongConstant
::= S_NUMBER
| S_PARAMETER

IntegerConstant
::= S_NUMBER
| S_PARAMETER

ArrayElementReference
::= '[' IntegerConstant ']'

ArrayValueConstructor
::= 'ARRAY' '[' SqlExpressionList ']'

Alias ::= 'AS'? ObjectName

FromClause
::= 'FROM' FromItem ( ',' FromItem )*

FromItem ::= SourceReferenceOrSubquery JoinedTable*

SourceReferenceOrSubquery
::= ( SourceReference | '(' SelectWithOrder ')' ) Alias?

SourceReference
::= ObjectName ( '.' ObjectName )? ( '/' ObjectName ( '.' ObjectName )? )*

JoinedTable
::= ( 'CROSS' | 'NATURAL' ( 'INNER' | ( 'LEFT' | 'RIGHT' | 'FULL' ) 'OUTER'? )? ) 'JOIN' SourceReferenceOrSubquery
| ( 'INNER' | ( 'LEFT' | 'RIGHT' | 'FULL' ) 'OUTER'? )? 'JOIN' SourceReferenceOrSubquery ( 'ON' SqlExpression | 'USING' '(' SourceFieldList ')' )?

SourceFieldList
::= SourceField ( ',' SourceField )*

WhereClause
::= 'WHERE' SqlExpression

GroupByClause
::= 'GROUP' 'BY' ( 'ALL' | 'DISTINCT' )? GroupingElementList

GroupingElementList
::= GroupingElement ( ',' GroupingElement )*

GroupingElement
::= EmptyGroupingSet
| OrdinaryGroupingSet
| RollupList
| CubeList
| GroupingSetsSpecification

EmptyGroupingSet
::= '(' ')'

OrdinaryGroupingSet
::= '(' GroupingExpressionReferenceList ')'
| GroupingExpressionReference

GroupingExpressionReferenceList
::= GroupingExpressionReference ( ',' GroupingExpressionReference )*

GroupingExpressionReference
::= SqlExpression

RollupList
::= 'ROLLUP' '(' OrdinaryGroupingSetList ')'

OrdinaryGroupingSetList
::= OrdinaryGroupingSet ( ',' OrdinaryGroupingSet )*

CubeList ::= 'CUBE' '(' OrdinaryGroupingSetList ')'

GroupingSetsSpecification
::= 'GROUPING' 'SETS' '(' GroupingSetList ')'

GroupingSetList
::= GroupingSet ( ',' GroupingSet )*

GroupingSet
::= EmptyGroupingSet
| OrdinaryGroupingSet
| RollupList
| CubeList
| GroupingSetsSpecification

HavingClause
::= 'HAVING' SqlExpression

LimitClause
::= 'LIMIT' LongConstant ( ',' LongConstant )?

S_NUMBER ::= FLOAT ( [eE] [-+]? INTEGER )?

FLOAT ::= ( INTEGER? '.' )? INTEGER

INTEGER ::= DIGIT+

DIGIT ::= [0-9]

S_PARAMETER
::= ':' ( S_IDENTIFIER | S_QUOTED_IDENTIFIER )

S_IDENTIFIER
::= NAMESTARTCHAR NAMECHAR*

NAMESTARTCHAR
::= [A-Z_a-z#x00C0-#x00D6#x00D8-#x00F6#x00F8-#x02FF#x0370-#x037D#x037F-#x1FFF#x200C-#x200D#x2070-#x218F#x2C00-#x2FEF#x3001-#xD7FF#xF900-#xFDCF#xFDF0-#xFFFD]

NAMECHAR ::= NAMESTARTCHAR
| [:$0-9#x00B7#x0300-#x036F#x203F-#x2040]

S_QUOTED_IDENTIFIER
::= '"' [^"#x000A#x000D]* '"'

S_CHAR_LITERAL
::= "'" ( "'" "'" | [^'] )* "'"

IgnorableWhitespace
::= [ #x0009#x000D#x000A]
| LINE_COMMENT
| MULTI_LINE_COMMENT

LINE_COMMENT
::= '--' [^#x000D#x000A]*

MULTI_LINE_COMMENT
::= '/' '*' ( [^*] | '*'+ [^*/] )* '*'+ '/'