Expression Syntax

An expression is a combination of one or more values, operators, or functions. In TiDB, expressions are mainly used in various clauses of the SELECT statement, including Group by clause, Where clause, Having clause, Join condition and window function. In addition, some DDL statements also use expressions, such as the setting of the default values, columns, and partition rules when creating tables.

The expressions can be divided into the following types:

The following rules are the expression syntax, which is based on the parser.y rules of TiDB parser. For the navigable version of the following syntax diagram, refer to TiDB SQL Syntax Diagram.

Expression
singleAtIdentifierassignmentEqNOTExpressionlogOrXORlogAndExpressionMATCH(ColumnNameList)AGAINST(BitExprFulltextSearchModifierOpt)PredicateExprIsOrNotOpNULLCompareOpsingleAtIdentifierassignmentEqPredicateExprAnyOrAllSubSelectIsOrNotOptrueKwdfalseKwdUNKNOWN
PredicateExpr
BitExprBetweenOrNotOpBitExprANDBitExprInOrNotOp(ExpressionList)SubSelectLikeOrNotOpSimpleExprLikeEscapeOptRegexpOrNotOpSimpleExpr
BitExpr
BitExpr|&<<>>*/%DIVMOD^BitExpr+-BitExprINTERVALExpressionTimeUnitSimpleExpr
SimpleExpr
SimpleIdent->->>stringLitFunctionCallKeywordFunctionCallNonKeywordFunctionCallGenericSimpleExprCOLLATECollationNamepipesSimpleExprWindowFuncCallLiteralparamMarkerVariableSumExpr!~-+NOTBINARYSimpleExprEXISTSSubSelect(ExpressionList,ROW(ExpressionList,ExpressionbuiltinCast(ExpressionASCastTypeDEFAULTVALUES(SimpleIdentCONVERT(Expression,CastTypeUSINGCharsetName)CASEExpressionOptWhenClauseElseOptEND