sql

package
v0.0.5 Latest Latest
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 Go to latest Published: Aug 2, 2019 License: Apache-2.0 Imports: 10 Imported by: 0

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Constants

This section is empty.

Variables

View Source 
var (

	// SQLParser is used to parse SQL statements
	SQLParser = participle.MustBuild(
		&Select{},
		participle.Lexer(sqlLexer),
		participle.CaseInsensitive("Keyword"),
		participle.CaseInsensitive("Timeword"),
	)
)

Functions

func FormatSQLTimestamp 

func FormatSQLTimestamp(t time.Time) string

FormatSQLTimestamp - returns the a string representation of the timestamp as used in S3 Select

Types

type AliasedExpression 

type AliasedExpression struct {
	Expression *Expression `parser:"@@"`
	As         string      `parser:"[ \"AS\" @Ident ]"`
}

AliasedExpression is an expression that can be optionally named

type AndCondition 

type AndCondition struct {
	Condition []*Condition `parser:"@@ ( \"AND\" @@ )*"`
}

AndCondition represents logical conjunction of clauses

type Between 

type Between struct {
	Not   bool     `parser:" @\"NOT\"? "`
	Start *Operand `parser:" \"BETWEEN\" @@ "`
	End   *Operand `parser:" \"AND\" @@ "`
}

Between represents the RHS of a BETWEEN expression

type Boolean 

type Boolean bool

Boolean is a type for a parsed Boolean literal

func (*Boolean) Capture 

func (b *Boolean) Capture(values []string) error

Capture interface used by participle

type CastFunc 

type CastFunc struct {
	Expr     *Expression `parser:" \"CAST\" \"(\" @@ "`
	CastType string      `` /* 128-byte string literal not displayed */
}

CastFunc represents CAST sql function

type Compare 

type Compare struct {
	Operator string   `parser:"@( \"<>\" | \"<=\" | \">=\" | \"=\" | \"<\" | \">\" | \"!=\" )"`
	Operand  *Operand `parser:"  @@"`
}

Compare represents the RHS of a comparison expression

type Condition 

type Condition struct {
	Operand *ConditionOperand `parser:"  @@"`
	Not     *Condition        `parser:"| \"NOT\" @@"`
}

Condition represents a negation or a condition operand

type ConditionOperand 

type ConditionOperand struct {
	Operand      *Operand      `parser:"@@"`
	ConditionRHS *ConditionRHS `parser:"@@?"`
}

ConditionOperand is a operand followed by an an optional operation expression

type ConditionRHS 

type ConditionRHS struct {
	Compare *Compare `parser:"  @@"`
	Between *Between `parser:"| @@"`
	In      *In      `parser:"| \"IN\" \"(\" @@ \")\""`
	Like    *Like    `parser:"| @@"`
}

ConditionRHS represents the right-hand-side of Compare, Between, In or Like expressions.

type CountFunc 

type CountFunc struct {
	StarArg bool        `parser:" \"COUNT\" \"(\" ( @\"*\"?"`
	ExprArg *Expression `parser:" @@? )! \")\""`
}

CountFunc represents the COUNT sql function

type DateAddFunc 

type DateAddFunc struct {
	DatePart  string       `` /* 161-byte string literal not displayed */
	Quantity  *Operand     `parser:" @@ \",\""`
	Timestamp *PrimaryTerm `parser:" @@ \")\""`
}

DateAddFunc represents the DATE_ADD function

type DateDiffFunc 

type DateDiffFunc struct {
	DatePart   string       `` /* 163-byte string literal not displayed */
	Timestamp1 *PrimaryTerm `parser:" @@ \",\" "`
	Timestamp2 *PrimaryTerm `parser:" @@ \")\" "`
}

DateDiffFunc represents the DATE_DIFF function

type Expression 

type Expression struct {
	And []*AndCondition `parser:"@@ ( \"OR\" @@ )*"`
}

Expression represents a logical disjunction of clauses

type ExtractFunc 

type ExtractFunc struct {
	Timeword string       `` /* 215-byte string literal not displayed */
	From     *PrimaryTerm `parser:" \"FROM\" @@ \")\" "`
}

ExtractFunc represents EXTRACT sql function

type FuncExpr 

type FuncExpr struct {
	SFunc     *SimpleArgFunc `parser:"  @@"`
	Count     *CountFunc     `parser:"| @@"`
	Cast      *CastFunc      `parser:"| @@"`
	Substring *SubstringFunc `parser:"| @@"`
	Extract   *ExtractFunc   `parser:"| @@"`
	Trim      *TrimFunc      `parser:"| @@"`
	DateAdd   *DateAddFunc   `parser:"| @@"`
	DateDiff  *DateDiffFunc  `parser:"| @@"`
	// contains filtered or unexported fields
}

FuncExpr represents a function call

type FuncName 

type FuncName string

FuncName - SQL function name.

type Identifier 

type Identifier struct {
	Unquoted *string           `parser:"  @Ident"`
	Quoted   *QuotedIdentifier `parser:"| @QuotIdent"`
}

Identifier represents a parsed identifier

func (*Identifier) String 

func (i *Identifier) String() string

Removes double quotes in quoted identifiers

type In 

type In struct {
	Expressions []*Expression `parser:"@@ ( \",\" @@ )*"`
}

In represents the RHS of an IN expression

type JSONPath 

type JSONPath struct {
	BaseKey  *Identifier        `parser:" @@"`
	PathExpr []*JSONPathElement `parser:"(@@)*"`
}

JSONPath represents a keypath

func (*JSONPath) String 

func (e *JSONPath) String() string

String - returns the JSONPath representation

type JSONPathElement 

type JSONPathElement struct {
	Key            *ObjectKey `parser:"  @@"`                  // ['name'] and .name forms
	Index          *int       `parser:"| \"[\" @Number \"]\""` // [3] form
	ObjectWildcard bool       `parser:"| @\".*\""`             // .* form
	ArrayWildcard  bool       `parser:"| @\"[*]\""`            // [*] form
}

JSONPathElement represents a keypath component

func (*JSONPathElement) String 

func (e *JSONPathElement) String() string

type Like 

type Like struct {
	Not        bool     `parser:" @\"NOT\"? "`
	Pattern    *Operand `parser:" \"LIKE\" @@ "`
	EscapeChar *Operand `parser:" (\"ESCAPE\" @@)? "`
}

Like represents the RHS of a LIKE expression

type LitValue 

type LitValue struct {
	Number  *float64       `parser:"(  @Number"`
	String  *LiteralString `parser:" | @LitString"`
	Boolean *Boolean       `parser:" | @(\"TRUE\" | \"FALSE\")"`
	Null    bool           `parser:" | @\"NULL\")"`
}

LitValue represents a literal value parsed from the sql

type LiteralString 

type LiteralString string

LiteralString is a type for parsed SQL string literals

func (*LiteralString) Capture 

func (ls *LiteralString) Capture(values []string) error

Capture interface used by participle

type MultOp 

type MultOp struct {
	Left  *UnaryTerm     `parser:"@@"`
	Right []*OpUnaryTerm `parser:"(@@)*"`
}

MultOp represents a single term followed by an optional sequence of terms separated by *, / or % operators.

type NegatedTerm 

type NegatedTerm struct {
	Term *PrimaryTerm `parser:"\"-\" @@"`
}

NegatedTerm has a leading minus sign.

type ObjectKey 

type ObjectKey struct {
	Lit *LiteralString `parser:" \"[\" @LitString \"]\""`
	ID  *Identifier    `parser:"| \".\" @@"`
}

ObjectKey is a type for parsed strings occurring in key paths

func (*ObjectKey) String 

func (o *ObjectKey) String() string

type OpFactor 

type OpFactor struct {
	Op    string  `parser:"@(\"+\" | \"-\")"`
	Right *MultOp `parser:"@@"`
}

OpFactor represents the right-side of a +/- operation.

type OpUnaryTerm 

type OpUnaryTerm struct {
	Op    string     `parser:"@(\"*\" | \"/\" | \"%\")"`
	Right *UnaryTerm `parser:"@@"`
}

OpUnaryTerm represents the right side of *, / or % binary operations.

type Operand 

type Operand struct {
	Left  *MultOp     `parser:"@@"`
	Right []*OpFactor `parser:"(@@)*"`
}

An Operand is a single term followed by an optional sequence of terms separated by +/-

type PrimaryTerm 

type PrimaryTerm struct {
	Value         *LitValue   `parser:"  @@"`
	JPathExpr     *JSONPath   `parser:"| @@"`
	SubExpression *Expression `parser:"| \"(\" @@ \")\""`
	// Include function expressions here.
	FuncCall *FuncExpr `parser:"| @@"`
}

PrimaryTerm represents a Value, Path expression, a Sub-expression or a function call.

type QuotedIdentifier 

type QuotedIdentifier string

QuotedIdentifier is a type for parsed strings that are double quoted.

func (*QuotedIdentifier) Capture 

func (qi *QuotedIdentifier) Capture(values []string) error

Capture interface used by participle

type Record 

type Record interface {
	Get(name string) (*Value, error)
	Set(name string, value *Value) error
	MarshalCSV(fieldDelimiter rune) ([]byte, error)
	MarshalJSON() ([]byte, error)

	// Returns underlying representation
	Raw() (SelectObjectFormat, interface{})

	// Replaces the underlying data
	Replace(k jstream.KVS) error
}

Record - is a type containing columns and their values.

type Select 

type Select struct {
	Expression *SelectExpression `parser:"\"SELECT\" @@"`
	From       *TableExpression  `parser:"\"FROM\" @@"`
	Where      *Expression       `parser:"( \"WHERE\" @@ )?"`
	Limit      *LitValue         `parser:"( \"LIMIT\" @@ )?"`
}

Select is the top level AST node type

type SelectExpression 

type SelectExpression struct {
	All         bool                 `parser:"  @\"*\""`
	Expressions []*AliasedExpression `parser:"| @@ { \",\" @@ }"`
}

SelectExpression represents the items requested in the select statement

type SelectObjectFormat 

type SelectObjectFormat int

SelectObjectFormat specifies the format of the underlying data 

const (
	// SelectFmtUnknown - unknown format (default value)
	SelectFmtUnknown SelectObjectFormat = iota
	// SelectFmtCSV - CSV format
	SelectFmtCSV
	// SelectFmtJSON - JSON format
	SelectFmtJSON
	// SelectFmtParquet - Parquet format
	SelectFmtParquet
)

type SelectStatement 

type SelectStatement struct {
	// contains filtered or unexported fields
}

SelectStatement is the top level parsed and analyzed structure

func ParseSelectStatement 

func ParseSelectStatement(s string) (stmt SelectStatement, err error)

ParseSelectStatement - parses a select query from the given string and analyzes it.

func (*SelectStatement) AggregateResult 

func (e *SelectStatement) AggregateResult(output Record) error

AggregateResult - returns the aggregated result after all input records have been processed. Applies only to aggregation queries.

func (*SelectStatement) AggregateRow 

func (e *SelectStatement) AggregateRow(input Record) error

AggregateRow - aggregates the input record. Applies only to aggregation queries.

func (*SelectStatement) Eval 

func (e *SelectStatement) Eval(input, output Record) (Record, error)

Eval - evaluates the Select statement for the given record. It applies only to non-aggregation queries.

func (*SelectStatement) EvalFrom 

func (e *SelectStatement) EvalFrom(format string, input Record) (Record, error)

EvalFrom evaluates the From clause on the input record. It only applies to JSON input data format (currently).

func (*SelectStatement) IsAggregated 

func (e *SelectStatement) IsAggregated() bool

IsAggregated returns if the statement involves SQL aggregation

func (*SelectStatement) LimitReached 

func (e *SelectStatement) LimitReached() bool

LimitReached - returns true if the number of records output has reached the value of the `LIMIT` clause.

type SimpleArgFunc 

type SimpleArgFunc struct {
	FunctionName string `` /* 193-byte string literal not displayed */

	ArgsList []*Expression `parser:"\"(\" (@@ (\",\" @@)*)?\")\""`
}

SimpleArgFunc represents functions with simple expression arguments.

type SubstringFunc 

type SubstringFunc struct {
	Expr *PrimaryTerm `parser:" \"SUBSTRING\" \"(\" @@ "`
	From *Operand     `parser:" ( \"FROM\" @@ "`
	For  *Operand     `parser:"   (\"FOR\" @@)? \")\" "`
	Arg2 *Operand     `parser:" | \",\" @@ "`
	Arg3 *Operand     `parser:"   (\",\" @@)? \")\" )"`
}

SubstringFunc represents SUBSTRING sql function

type TableExpression 

type TableExpression struct {
	Table *JSONPath `parser:"@@"`
	As    string    `parser:"( \"AS\"? @Ident )?"`
}

TableExpression represents the FROM clause

func (*TableExpression) HasKeypath 

func (from *TableExpression) HasKeypath() bool

HasKeypath returns if the from clause has a key path - e.g. S3object[*].id

type TrimFunc 

type TrimFunc struct {
	TrimWhere *string      `parser:" \"TRIM\" \"(\" ( @( \"LEADING\" | \"TRAILING\" | \"BOTH\" ) "`
	TrimChars *PrimaryTerm `parser:"             @@?  "`
	TrimFrom  *PrimaryTerm `parser:"             \"FROM\" )? @@ \")\" "`
}

TrimFunc represents TRIM sql function

type UnaryTerm 

type UnaryTerm struct {
	Negated *NegatedTerm `parser:"  @@"`
	Primary *PrimaryTerm `parser:"| @@"`
}

UnaryTerm represents a single negated term or a primary term

type Value 

type Value struct {
	// contains filtered or unexported fields
}

Value represents a value of restricted type reduced from an expression represented by an ASTNode. Only one of the fields is non-nil.

In cases where we are fetching data from a data source (like csv), the type may not be determined yet. In these cases, a byte-slice is used.

func FromBool 

func FromBool(b bool) *Value

FromBool creates a Value from a bool

func FromBytes 

func FromBytes(b []byte) *Value

FromBytes creates a Value from a []byte

func FromFloat 

func FromFloat(f float64) *Value

FromFloat creates a Value from a number

func FromInt 

func FromInt(f int64) *Value

FromInt creates a Value from an int

func FromNull 

func FromNull() *Value

FromNull creates a Value with Null value

func FromString 

func FromString(str string) *Value

FromString creates a Value from a string

func FromTimestamp 

func FromTimestamp(t time.Time) *Value

FromTimestamp creates a Value from a timestamp

func (*Value) CSVString 

func (v *Value) CSVString() string

CSVString - convert to string for CSV serialization

func (*Value) GetTypeString 

func (v *Value) GetTypeString() string

GetTypeString returns a string representation for vType

func (*Value) IsNull 

func (v *Value) IsNull() bool

IsNull - checks if value is missing.

func (*Value) Repr 

func (v *Value) Repr() string

Repr returns a string representation of value.

func (*Value) ToBool 

func (v *Value) ToBool() (val bool, ok bool)

ToBool returns the bool value; second return value refers to if the bool conversion succeeded.

func (*Value) ToBytes 

func (v *Value) ToBytes() ([]byte, bool)

ToBytes converts Value to byte-slice.

func (*Value) ToFloat 

func (v *Value) ToFloat() (val float64, ok bool)

ToFloat works for int and float values

func (*Value) ToInt 

func (v *Value) ToInt() (val int64, ok bool)

ToInt converts value to int.

func (*Value) ToString 

func (v *Value) ToString() (val string, ok bool)

ToString converts value to string.

func (*Value) ToTimestamp 

func (v *Value) ToTimestamp() (t time.Time, ok bool)

ToTimestamp returns the timestamp value if present.

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