Expression 使用手册¶
buildin Function映射表¶
mysql中支持内置函数，内置函数在词法分析阶段就会被解析成特定的终结符类型，下面给出内置函数到终结符类型的映射关系表。
| 函数名 | 终结符类型 |
|---|---|
| ADDDATE | builtinAddDate |
| BIT_AND | builtinBitAnd |
| BIT_OR | builtinBitOr |
| BIT_XOR | builtinBitXor |
| CAST | builtinCast |
| COUNT | builtinCount |
| CURDATE | builtinCurDate |
| CURTIME | builtinCurTime |
| DATE_ADD | builtinDateAdd |
| DATE_SUB | builtinDateSub |
| EXTRACT | builtinExtract |
| GROUP_CONCAT | builtinGroupConcat |
| MAX | builtinMax |
| MID | builtinSubstring |
| MIN | builtinMin |
| NOW | builtinNow |
| POSITION | builtinPosition |
| SESSION_USER | builtinUser |
| STD | builtinStddevPop |
| STDDEV | builtinStddevPop |
| STDDEV_POP | builtinStddevPop |
| STDDEV_SAMP | builtinStddevSamp |
| SUBDATE | builtinSubDate |
| SUBSTR | builtinSubstring |
| SUBSTRING | builtinSubstring |
| SUM | builtinSum |
| SYSDATE | builtinSysDate |
| SYSTEM_USER | builtinUser |
| TRIM | builtinTrim |
| VARIANCE | builtinVarPop |
| VAR_POP | builtinVarPop |
| VAR_SAMP | builtinVarSamp |
%token <ident>pipes “||”
- singleAtIdentifier “identifier with single leading at”
- doubleAtIdentifier “identifier with double leading at”
binaryType “BINARY”
- %token <item>
assignmentEq “:=”
/* The following tokens belong to ReservedKeyword. Notice: make sure these tokens are contained in ReservedKeyword. */ falseKwd “FALSE” trueKwd “TRUE”
/* The following tokens belong to UnReservedKeyword. Notice: make sure these tokens are contained in UnReservedKeyword. */ pipesAsOr weightString “WEIGHT_STRING”
/* The following tokens belong to TiDBKeyword. Notice: make sure these tokens are contained in TiDBKeyword. */ builtinAddDate builtinBitAnd builtinBitOr builtinBitXor builtinCast builtinCount builtinCurDate builtinCurTime builtinDateAdd builtinDateSub builtinExtract builtinGroupConcat builtinMax builtinMin builtinNow builtinPosition builtinSubDate builtinSubstring builtinSum builtinSysDate builtinStddevPop builtinStddevSamp builtinTrim builtinUser builtinVarPop builtinVarSamp
- %token <item>
- jss “->” juss “->>”
%%
- Expression:
- singleAtIdentifier assignmentEq Expression
Expression logOr ExpressionExpression “XOR” ExpressionExpression logAnd Expression“NOT” ExpressionBoolPri IsOrNotOp trueKwdBoolPri IsOrNotOp falseKwdBoolPri
- BitExpr:
- BitExpr ‘|’ BitExpr
BitExpr ‘&’ BitExprBitExpr “<<” BitExprBitExpr “>>” BitExprBitExpr ‘+’ BitExprBitExpr ‘-’ BitExprBitExpr ‘*’ BitExprBitExpr ‘/’ BitExprBitExpr ‘%’ BitExprBitExpr “DIV” BitExprBitExpr “MOD” BitExprBitExpr ‘^’ BitExprSimpleExpr
- SimpleExpr:
- SimpleIdent
FunctionCallKeywordFunctionCallNonKeywordFunctionCallGenericLiteralSumExpr‘!’ SimpleExpr‘~’ SimpleExpr‘-’ SimpleExpr‘+’ SimpleExprSimpleExpr pipes SimpleExprnot2 SimpleExprSubSelect‘(’ Expression ‘)’‘(’ ExpressionList ‘,’ Expression ‘)’“ROW” ‘(’ ExpressionList ‘,’ Expression ‘)’“EXISTS” SubSelect“BINARY” SimpleExprbuiltinCast ‘(’ Expression “AS” CastType ‘)’“CASE” ExpressionOpt WhenClauseList ElseOpt “END”“CONVERT” ‘(’ Expression ‘,’ CastType ‘)’
- SimpleIdent:
- Identifier
Identifier ‘.’ Identifier‘.’ Identifier ‘.’ Identifier
- BoolPri:
- BoolPri IsOrNotOp “NULL”
BoolPri CompareOp PredicateExprBoolPri CompareOp AnyOrAll SubSelectPredicateExpr
- PredicateExpr:
- BitExpr InOrNotOp ‘(’ ExpressionList ‘)’
BitExpr InOrNotOp SubSelectBitExpr BetweenOrNotOp BitExpr “AND” PredicateExprBitExpr LikeOrNotOp SimpleExpr LikeEscapeOptBitExpr RegexpOrNotOp SimpleExprBitExpr
- InOrNotOp:
- “IN”
“NOT” “IN”
- ExpressionList:
- Expression
ExpressionList ‘,’ Expression//FulltextSearchModifierOpt: // /* empty */
- ColumnNameList:
- ColumnName
ColumnNameList ‘,’ ColumnName
- ColumnName:
- Identifier
Identifier ‘.’ Identifier
- IsOrNotOp:
- “IS”
“IS” “NOT”
- BetweenOrNotOp:
- “BETWEEN”
“NOT” “BETWEEN”
- LikeOrNotOp:
- “LIKE”
“NOT” “LIKE”
- LikeEscapeOpt:
- /* empty */
“ESCAPE” stringLit
- RegexpOrNotOp:
- RegexpSym
“NOT” RegexpSym
- RegexpSym:
- “REGEXP”
“RLIKE”
- logOr:
- pipesAsOr
“OR”
- CompareOp:
- “>=”
‘>’“<=”‘<’“!=”“<>”“=”“<=>” // NullEQ
- AnyOrAll:
- “ANY”
“SOME”“ALL”
- SubSelect:
- ‘(’ SelectStmt ‘)’ // please see DQL
‘(’ SetOprStmt ‘)’ // please see DQL
- FunctionCallKeyword:
- FunctionNameConflict ‘(’ ExpressionListOpt ‘)’
FunctionNameOptionalBraces OptionalBracesbuiltinCurDate ‘(’ ‘)’FunctionNameDatetimePrecision FuncDatetimePrec“MOD” ‘(’ BitExpr ‘,’ BitExpr ‘)’
- FunctionCallNonKeyword:
- builtinCurTime ‘(’ FuncDatetimePrecListOpt ‘)’
builtinTrim ‘(’ Expression ‘)’builtinTrim ‘(’ Expression “FROM” Expression ‘)’builtinTrim ‘(’ TrimDirection “FROM” Expression ‘)’builtinTrim ‘(’ TrimDirection Expression “FROM” Expression ‘)’
- FunctionCallGeneric:
- identifier ‘(’ ExpressionListOpt ‘)’
Identifier ‘.’ Identifier ‘(’ ExpressionListOpt ‘)’
- ExpressionListOpt:
- /* empty */
ExpressionListFunctionNameConflict: | “IF”
FunctionNameOptionalBraces: | “CURRENT_DATE” | “UTC_DATE”
- FunctionNameDatetimePrecision:
- “CURRENT_TIME”
“CURRENT_TIMESTAMP”“UTC_TIME”“UTC_TIMESTAMP”
- OptionalBraces:
- /* empty */
‘(’ ‘)’
- FuncDatetimePrec:
- /* empty */
‘(’ ‘)’‘(’ intLit ‘)’
- StringName:
- stringLit
Identifier
- FuncDatetimePrecListOpt:
- /* empty */
FuncDatetimePrecList
- FuncDatetimePrecList:
- intLit
- TableName:
- Identifier
Identifier ‘.’ Identifier
- SignedNum:
- Int64Num
‘+’ Int64Num‘-’ NUM
- Int64Num:
- NUM
- NUM:
- intLit
- Literal:
- “FALSE”
“NULL”“TRUE”floatLitdecLitintLitStringLiteral“UNDERSCORE_CHARSET” stringLithexLitbitLit
- StringLiteral:
- stringLit
StringLiteral stringLit
- SumExpr:
- “AVG” ‘(’ BuggyDefaultFalseDistinctOpt Expression ‘)’
builtinBitAnd ‘(’ Expression ‘)’builtinBitAnd ‘(’ “ALL” Expression ‘)’builtinBitOr ‘(’ Expression ‘)’builtinBitOr ‘(’ “ALL” Expression ‘)’builtinBitXor ‘(’ Expression ‘)’builtinBitXor ‘(’ “ALL” Expression ‘)’builtinCount ‘(’ DistinctKwd ExpressionList ‘)’builtinCount ‘(’ “ALL” Expression ‘)’builtinCount ‘(’ Expression ‘)’builtinCount ‘(’ ‘*’ ‘)’builtinGroupConcat ‘(’ BuggyDefaultFalseDistinctOpt ExpressionList OrderByOptional OptGConcatSeparator ‘)’builtinMax ‘(’ BuggyDefaultFalseDistinctOpt Expression ‘)’builtinMin ‘(’ BuggyDefaultFalseDistinctOpt Expression ‘)’builtinSum ‘(’ BuggyDefaultFalseDistinctOpt Expression ‘)’builtinStddevPop ‘(’ BuggyDefaultFalseDistinctOpt Expression ‘)’builtinStddevSamp ‘(’ BuggyDefaultFalseDistinctOpt Expression ‘)’builtinVarPop ‘(’ BuggyDefaultFalseDistinctOpt Expression ‘)’builtinVarSamp ‘(’ BuggyDefaultFalseDistinctOpt Expression ‘)’
- BuggyDefaultFalseDistinctOpt:
- DefaultFalseDistinctOpt
DistinctKwd “ALL”
- DefaultFalseDistinctOpt:
- /* empty */
DistinctOpt
- DistinctOpt:
- “ALL”
DistinctKwd
- DistinctKwd:
- “DISTINCT”
“DISTINCTROW”
- OrderByOptional:
- /* empty */
OrderBy
- OrderBy:
- “ORDER” “BY” ByList
- OrderBy:
- “ORDER” “BY” ByList
- ByList:
- ByItem
ByList ‘,’ ByItem
- ByItem:
- Expression Order
- Order:
- /* EMPTY */
“ASC”“DESC”
- OptGConcatSeparator:
- /* empty */
“SEPARATOR” stringLit
- CastType:
- “BINARY” OptFieldLen
Char OptFieldLen OptBinary“DATE”“DATETIME” OptFieldLen“DECIMAL” FloatOpt“TIME” OptFieldLen“SIGNED” OptInteger“UNSIGNED” OptInteger//| “JSON” | “DOUBLE” | “FLOAT” FloatOpt | “REAL”
- OptFieldLen:
- /* empty */
FieldLenFieldLenPrecision
- Precision:
- ‘(’ LengthNum ‘,’ LengthNum ‘)’
- OptInteger:
- /* empty */
“INTEGER”“INT”
- ExpressionOpt:
- /* empty */
Expression
- WhenClauseList:
- WhenClause
WhenClauseList WhenClause
- WhenClause:
- “WHEN” Expression “THEN” Expression
- ElseOpt:
- /* empty */
“ELSE” Expression