我在Delphi(2010)为sql Server寻找一个好的sql解析器.我需要这样的东西来解析一个查询并提取:select list,where and order by子句.无论是商业还是开源解决方案都没关系.它也可以是一个DLL(当然用任何语言编写),但是我更喜欢使用VCL组件.
解决方法
Rafael Delphi自带了一个位于DBCommon单元中的sql解析器
检查这些功能
function NextsqlToken(var p: PAnsiChar; out Token: AnsiString; CurSection: TsqlToken): TsqlToken; overload; function NextsqlToken(var p: PWideChar; out Token: WideString; CurSection: TsqlToken): TsqlToken; overload; function NextsqlToken(var p: PChar; out Token: String; CurSection: TsqlToken): TsqlToken; overload; function GetIndexForOrderBy(const sql: WideString; DataSet: TDataSet): TIndexDef; function GetTableNameFromsql(const sql: WideString): WideString; function GetTableNameFromQuery(const sql: Widestring): Widestring; function AddParamsqlForDetail(Params: TParams; sql: WideString; Native: Boolean; QuoteChar: WideString = ''): WideString; function IsMultiTableQuery(const sql: WideString): Boolean; function sqlRequiresParams(const sql: WideString): Boolean; function NextsqlTokenEx(var p: PWideChar; out Token: UnicodeString; CurSection: TsqlToken; IdOption: IDENTIFIEROption): TsqlToken; overload; function NextsqlTokenEx(var p: PWideChar; out Token: WideString; CurSection: TsqlToken; IdOption: IDENTIFIEROption): TsqlToken; overload; function NextsqlTokenEx(var p: PAnsiChar; out Token: AnsiString; CurSection: TsqlToken; IdOption: IDENTIFIEROption): TsqlToken; overload; function GetTableNameFromsqlEx(const sql: WideString; IdOption: IDENTIFIEROption): WideString;
这是一个非常简单的示例来显示如何解析sql语句并获取所有元素.
uses TypInfo,DbCommon,SysUtils; const Strsql ='Select Field1,Field2,54 field3,Field4 from Mytable1 Order by Field1,Field5'; procedure Parsesql(Const sql : string); var sqlToken : TsqlToken; CurSection : TsqlToken; Start : PWideChar; Token : WideString; IdOption : IDENTIFIEROption; begin IdOption :=idMixCase; Start :=PWideChar(Strsql); CurSection := stUnknown; repeat sqlToken := NextsqlTokenEx(Start,Token,CurSection,IdOption); if sqlToken<>stEnd then Writeln(Format('Type %s Token %s',[GetEnumName(TypeInfo(TsqlToken),integer(sqlToken)),Token])); CurSection := sqlToken; until sqlToken in [stEnd]; end; begin try Parsesql(Strsql); except on E: Exception do Writeln(E.ClassName,': ',E.Message); end; Readln; end.
这将返回
Type stSelect Token Select Type stFieldName Token Field1 Type stFieldName Token Field2 Type stNumber Token 54 Type stFieldName Token field3 Type stFieldName Token Field4 Type stFrom Token from Type stTableName Token Mytable1 Type stOrderBy Token Order by Type stFieldName Token Field1 Type stFieldName Token Field5