expression-syntax.md

title	summary	category
Expression Syntax	Learn about the expression syntax in TiDB.	reference

Expression Syntax

The following rules define the expression syntax in TiDB. You can find the definition in parser/parser.y. The syntax parsing in TiDB is based on Yacc.

Expression:
      singleAtIdentifier assignmentEq Expression
    | Expression logOr Expression
    | Expression "XOR" Expression
    | Expression logAnd Expression
    | "NOT" Expression
    | Factor IsOrNotOp trueKwd
    | Factor IsOrNotOp falseKwd
    | Factor IsOrNotOp "UNKNOWN"
    | Factor

Factor:
      Factor IsOrNotOp "NULL"
    | Factor CompareOp PredicateExpr
    | Factor CompareOp singleAtIdentifier assignmentEq PredicateExpr
    | Factor CompareOp AnyOrAll SubSelect
    | PredicateExpr

PredicateExpr:
      PrimaryFactor InOrNotOp '(' ExpressionList ')'
    | PrimaryFactor InOrNotOp SubSelect
    | PrimaryFactor BetweenOrNotOp PrimaryFactor "AND" PredicateExpr
    | PrimaryFactor LikeOrNotOp PrimaryExpression LikeEscapeOpt
    | PrimaryFactor RegexpOrNotOp PrimaryExpression
    | PrimaryFactor

PrimaryFactor:
      PrimaryFactor '|' PrimaryFactor
    | PrimaryFactor '&' PrimaryFactor
    | PrimaryFactor "<<" PrimaryFactor
    | PrimaryFactor ">>" PrimaryFactor
    | PrimaryFactor '+' PrimaryFactor
    | PrimaryFactor '-' PrimaryFactor
    | PrimaryFactor '*' PrimaryFactor
    | PrimaryFactor '/' PrimaryFactor
    | PrimaryFactor '%' PrimaryFactor
    | PrimaryFactor "DIV" PrimaryFactor
    | PrimaryFactor "MOD" PrimaryFactor
    | PrimaryFactor '^' PrimaryFactor
    | PrimaryExpression

PrimaryExpression:
      Operand
    | FunctionCallKeyword
    | FunctionCallNonKeyword
    | FunctionCallAgg
    | FunctionCallGeneric
    | Identifier jss stringLit
    | Identifier juss stringLit
    | SubSelect
    | '!' PrimaryExpression
    | '~'  PrimaryExpression
    | '-' PrimaryExpression
    | '+' PrimaryExpression
    | "BINARY" PrimaryExpression
    | PrimaryExpression "COLLATE" StringName