Documentation ¶
Overview ¶
Example (ParseSQL) ¶
This example show how to parse a text sql into ast.
package main import ( "fmt" "github.com/pingcap/parser" _ "github.com/pingcap/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) }
Output:
Index ¶
- Variables
- func DigestHash(sql string) (result string)
- func Normalize(sql string) (result string)
- func NormalizeDigest(sql string) (normalized, digest string)
- func ParseErrorWith(errstr string, lineno int) error
- func TrimComment(txt string) string
- type Parser
- type Pos
- type Scanner
- func (s *Scanner) AppendError(err error)
- func (s *Scanner) EnableWindowFunc(val bool)
- func (s *Scanner) Errorf(format string, a ...interface{}) (err error)
- func (s *Scanner) Errors() (warns []error, errs []error)
- func (s *Scanner) GetSQLMode() mysql.SQLMode
- func (s *Scanner) InheritScanner(sql string) *Scanner
- func (s *Scanner) Lex(v *yySymType) int
- func (s *Scanner) SetSQLMode(mode mysql.SQLMode)
Examples ¶
Constants ¶
This section is empty.
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]) // ErrUnknownCharacterSet returns for no character set found error. ErrUnknownCharacterSet = terror.ClassParser.New(codeErrUnknownCharacterSet, mysql.MySQLErrName[mysql.ErrUnknownCharacterSet]) // ErrInvalidYearColumnLength returns for illegal column length for year type. ErrInvalidYearColumnLength = terror.ClassParser.New(codeErrInvalidYearColumnLength, mysql.MySQLErrName[mysql.ErrInvalidYearColumnLength]) // ErrWrongArguments returns for illegal argument. ErrWrongArguments = terror.ClassParser.New(codeWrongArgument, mysql.MySQLErrName[mysql.ErrWrongArguments]) // ErrWrongFieldTerminators returns for illegal field terminators. ErrWrongFieldTerminators = terror.ClassParser.New(codeWrongFieldTerminators, mysql.MySQLErrName[mysql.ErrWrongFieldTerminators]) // ErrTooBigDisplayWidth returns for data display width exceed limit . ErrTooBigDisplayWidth = terror.ClassParser.New(codeTooBigDisplayWidth, mysql.MySQLErrName[mysql.ErrTooBigDisplaywidth]) // SpecFieldPattern special result field pattern SpecFieldPattern = regexp.MustCompile(`(\/\*!(M?[0-9]{5,6})?|\*\/)`) )
Functions ¶
func DigestHash ¶
DigestHash generates the digest of statements. it will generate a hash on normalized form of statement text which removes general property of a statement but keeps specific property.
for example: both DigestHash('select 1') and DigestHash('select 2') => e1c71d1661ae46e09b7aaec1c390957f0d6260410df4e4bc71b9c8d681021471
func Normalize ¶
Normalize generates the normalized statements. it will get normalized form of statement text which removes general property of a statement but keeps specific property.
for example: Normalize('select 1 from b where a = 1') => 'select ? from b where a = ?'
func NormalizeDigest ¶
NormalizeDigest combines Normalize and DigestHash into one method.
func ParseErrorWith ¶
ParseErrorWith returns "You have a syntax error near..." error message compatible with mysql.
func TrimComment ¶
TrimComment trim comment for special comment code of MySQL.
Types ¶
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 (*Parser) EnableWindowFunc ¶
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 ¶
ParseOneStmt parses a query and returns an ast.StmtNode. The query must have one statement, otherwise ErrSyntax is returned.
func (*Parser) SetSQLMode ¶
SetSQLMode sets the SQL mode for parser.
type Scanner ¶
type Scanner struct {
// contains filtered or unexported fields
}
Scanner implements the yyLexer interface.
func (*Scanner) AppendError ¶
AppendError sets error into scanner. Scanner satisfies yyLexer interface which need this function.
func (*Scanner) EnableWindowFunc ¶
EnableWindowFunc controls whether the scanner recognize the keywords of window function.
func (*Scanner) Errorf ¶
Errorf tells scanner something is wrong. Scanner satisfies yyLexer interface which need this function.
func (*Scanner) GetSQLMode ¶
GetSQLMode return the SQL mode of scanner.
func (*Scanner) InheritScanner ¶
InheritScanner returns a new scanner object which inherits configurations from the parent scanner.
func (*Scanner) Lex ¶
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 ¶
SetSQLMode sets the SQL mode for scanner.
Directories ¶
Path | Synopsis |
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Package ast is the abstract syntax tree parsed from a SQL statement by parser.
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Package ast is the abstract syntax tree parsed from a SQL statement by parser. |
Goyacc is a version of yacc generating Go parsers.
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Goyacc is a version of yacc generating Go parsers. |