Asp.net keyword fuzzy query (similar to the search function of major websites)

I would like to share with you todayAlgorithmI wrote it in C #. Other languages just need to change the syntax. Fuzzy search with a space disconnection keyword is similar to the search function of major websites. What I want is a process of splicing SQL statements. The Delimiter is a space disconnection keyword. In either case, the Delimiter is a space disconnection relationship that is "and", and the Delimiter is a space disconnection relationship that is "or. In fact, it is also very simple.CodeRight.

Link code of the keyword "or:

 ///   <Summary>      ///  Relationship of keyword "or"  ///   </Summary>      ///   <Returns> </returns>      Public   String Orkeywords (){  String SQL = "  Select username from usertable where 1 = 1  "  ;  String Txtkeyword = Txttitle. Text. Trim ();  If (Txtkeyword = ""  ) {Clientscript. registerstartupscript (  Typeof (Page ), " AA  " , "  Alert ('enter a keyword! ')  " , True  );  Return  ;}  Else  {  Int Len = Txtkeyword. length;  Int N = 0 ;  String Strsql = "  And (  "  ;  String Strkey = ""  ;  For ( Int I = 0 ; I <Len; I ++ ){  If (Txtkeyword [I]. tostring () ="   "  ){  If (I> 0  ){  If (Txtkeyword [I- 1 ]. Tostring ()! = "   "  ) {N ++ ; Strsql + = " Charindex ('  " + Strkey + "  ', Username)> 0 or  "  ; Strkey = ""  ;}}}  Else  {Strkey + = Txtkeyword [I]. tostring ();}}  If (N =0  ) {SQL + = "  And charindex ('  " + Txtkeyword + "  ', Username)> 0 order by ID DESC  "  ;}  Else  {Strsql + = "  Charindex ('  " + Strkey +"  ', Username)> 0)  "  ; SQL + = "" + Strsql + "  Order by ID DESC  "  ;}  //  Splicing completed              Return  SQL ;}} 

Link code with the keyword "and:

 ///  <Summary>      ///  Relationship of the keyword "and"  ///   </Summary>      ///   <Returns> </returns>      Public   String  Andkeywords (){  String SQL = "  Select username from usertable where 1 = 1  "  ; String Txtkeyword = Txttitle. Text. Trim ();  If (Ttxtkeyword = ""  ) {Clientscript. registerstartupscript (  Typeof (Page ), "  AA  " , "  Alert ('enter a keyword! ')  " , True  ); Return  ;}  Else  {  Int Len = Txtkeyword. length;  Int N = 0  ;  String Strsql = "  And  "  ;  String Strkey =""  ;  For ( Int I = 0 ; I <Len; I ++ ){  If (Txtkeyword [I]. tostring () = "   "  ){  If (I> 0  ){  If (Txtkeyword [I- 1 ]. Tostring ()! = "   "  ) {N ++ ; Strsql + = "  Charindex ('  " + Strkey + "  ', Username)> 0 and  "  ; Strkey = "" ;}}}  Else  {Strkey + = Txtkeyword [I]. tostring ();}}  If (N = 0  ) {SQL + = "  And charindex ('  " + Txtkeyword + "  ', Username)> 0 order by ID DESC "  ;}  Else  {Strsql + = "  Charindex ('  " + Strkey + "  ', Username)> 0  "  ; SQL + = "" + Strsql + "  Order by ID DESC  " ;}  //  Splicing completed              Return  SQL ;}} 

The code is very simple. I will not explain it. I will record it myself and hope it will help you.

PS: Tandy tang I wish you a pleasant time writing your code!