parser

Documentation

Overview

Example (ParseSQL)

This example show how to parse a text sql into ast.

package main

import (
	"fmt"

	"github.com/XiaoMi/Gaea/parser"
	_ "github.com/XiaoMi/Gaea/parser/tidb-types/parser_driver"
)

func main() {

	// 0. make sure import parser_driver implemented by TiDB(user also can implement own driver by self).
	// and add `import _ "github.com/pingcap/tidb/types/parser_driver"` in the head of file.

	// 1. Create a parser. The parser is NOT goroutine safe and should
	// not be shared among multiple goroutines. However, parser is also
	// heavy, so each goroutine should reuse its own local instance if
	// possible.
	p := parser.New()

	// 2. Parse a text SQL into AST([]ast.StmtNode).
	stmtNodes, _, err := p.Parse("select * from tbl where id = 1", "", "")

	// 3. Use AST to do cool things.
	fmt.Println(stmtNodes[0], err)
}

Index

• Constants
• Variables
• func NodeToStringWithoutQuote(node ast.Node) (string, error)
• func ParseErrorWith(errstr string, lineno int) error
• func ParseSQL(sql string) (ast.StmtNode, error)
• func Preview(sql string) int
• func StmtType(stmtType int) string
• func StripLeadingComments(sql string) string
• func TrimComment(txt string) string
• type CommentDirectives
  • func (d CommentDirectives) IsSet(key string) bool
• type MarginComments
  • func SplitMarginComments(sql string) (query string, comments MarginComments)
• type Parser
  • func New() *Parser
  • func (parser *Parser) EnableWindowFunc(val bool)
  • func (parser *Parser) Parse(sql, charset, collation string) (stmt []ast.StmtNode, warns []error, err error)
  • func (parser *Parser) ParseOneStmt(sql, charset, collation string) (ast.StmtNode, error)
  • func (parser *Parser) SetSQLMode(mode mysql.SQLMode)
• type Pos
• type Scanner
  • func NewScanner(s string) *Scanner
  • func (s *Scanner) EnableWindowFunc(val bool)
  • func (s *Scanner) Errorf(format string, a ...interface{})
  • func (s *Scanner) Errors() (warns []error, errs []error)
  • func (s *Scanner) GetSQLMode() mysql.SQLMode
  • func (s *Scanner) Lex(v *yySymType) int
  • func (s *Scanner) SetSQLMode(mode mysql.SQLMode)

Examples

• Package (ParseSQL)

Constants

const (
	StmtSelect = iota
	StmtStream
	StmtInsert
	StmtReplace
	StmtUpdate
	StmtDelete
	StmtDDL
	StmtBegin
	StmtCommit
	StmtRollback
	StmtSet
	StmtShow
	StmtUse
	StmtOther
	StmtUnknown
	StmtComment
	StmtSavepoint
)

These constants are used to identify the SQL statement type.

Variables

var (
	// ErrSyntax returns for sql syntax error.
	ErrSyntax = terror.ClassParser.New(codeErrSyntax, mysql.MySQLErrName[mysql.ErrSyntax])
	// ErrParse returns for sql parse error.
	ErrParse = terror.ClassParser.New(codeErrParse, mysql.MySQLErrName[mysql.ErrParse])
	// SpecFieldPattern special result field pattern
	SpecFieldPattern = regexp.MustCompile(`(\/\*!(M?[0-9]{5,6})?|\*\/)`)
)

Functions

func NodeToStringWithoutQuote

func NodeToStringWithoutQuote(node ast.Node) (string, error)

NodeToStringWithoutQuote get node text

func ParseErrorWith

func ParseErrorWith(errstr string, lineno int) error

ParseErrorWith returns "You have a syntax error near..." error message compatible with mysql.

func ParseSQL

func ParseSQL(sql string) (ast.StmtNode, error)

ParseSQL only for test, use ClientConn.parser for handling request

func Preview

func Preview(sql string) int

Preview analyzes the beginning of the query using a simpler and faster textual comparison to identify the statement type.

func StmtType

func StmtType(stmtType int) string

StmtType returns the statement type as a string

func StripLeadingComments

func StripLeadingComments(sql string) string

StripLeadingComments trims the SQL string and removes any leading comments

func TrimComment

func TrimComment(txt string) string

TrimComment trim comment for special comment code of MySQL.

Types

type CommentDirectives

type CommentDirectives map[string]interface{}

CommentDirectives is the parsed representation for execution directives conveyed in query comments

func (CommentDirectives) IsSet

func (d CommentDirectives) IsSet(key string) bool

IsSet checks the directive map for the named directive and returns true if the directive is set and has a true/false or 0/1 value

type MarginComments

type MarginComments struct {
	Leading  string
	Trailing string
}

MarginComments holds the leading and trailing comments that surround a query.

func SplitMarginComments

func SplitMarginComments(sql string) (query string, comments MarginComments)

SplitMarginComments pulls out any leading or trailing comments from a raw sql query. This function also trims leading (if there's a comment) and trailing whitespace.

type Parser

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

Parser represents a parser instance. Some temporary objects are stored in it to reduce object allocation during Parse function.

func New

func New() *Parser

New returns a Parser object.

func (*Parser) EnableWindowFunc

func (parser *Parser) EnableWindowFunc(val bool)

EnableWindowFunc controls whether the parser to parse syntax related with window function.

func (*Parser) Parse

func (parser *Parser) Parse(sql, charset, collation string) (stmt []ast.StmtNode, warns []error, err error)

Parse parses a query string to raw ast.StmtNode. If charset or collation is "", default charset and collation will be used.

func (*Parser) ParseOneStmt

func (parser *Parser) ParseOneStmt(sql, charset, collation string) (ast.StmtNode, error)

ParseOneStmt parses a query and returns an ast.StmtNode. The query must have one statement, otherwise ErrSyntax is returned.

func (*Parser) SetSQLMode

func (parser *Parser) SetSQLMode(mode mysql.SQLMode)

SetSQLMode sets the SQL mode for parser.

type Pos

type Pos struct {
	Line   int
	Col    int
	Offset int
}

Pos represents the position of a token.

type Scanner

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

Scanner implements the yyLexer interface.

func NewScanner

func NewScanner(s string) *Scanner

NewScanner returns a new scanner object.

func (*Scanner) EnableWindowFunc

func (s *Scanner) EnableWindowFunc(val bool)

EnableWindowFunc controls whether the scanner recognize the keywords of window function.

func (*Scanner) Errorf

func (s *Scanner) Errorf(format string, a ...interface{})

Errorf tells scanner something is wrong. Scanner satisfies yyLexer interface which need this function.

func (*Scanner) Errors

func (s *Scanner) Errors() (warns []error, errs []error)

Errors returns the errors and warns during a scan.

func (*Scanner) GetSQLMode

func (s *Scanner) GetSQLMode() mysql.SQLMode

GetSQLMode return the SQL mode of scanner.

func (*Scanner) Lex

func (s *Scanner) Lex(v *yySymType) int

Lex returns a token and store the token value in v. Scanner satisfies yyLexer interface. 0 and invalid are special token id this function would return: return 0 tells parser that scanner meets EOF, return invalid tells parser that scanner meets illegal character.

func (*Scanner) SetSQLMode

func (s *Scanner) SetSQLMode(mode mysql.SQLMode)

SetSQLMode sets the SQL mode for scanner.