我正在使用MSsql 2008的全文搜索引擎,它需要一个像这样的搜索字符串：
("keyword1" AND "keyword2*" OR "keyword3")
engine 2009 "san francisco" hotel december xyz stuff* "in miami" 1234 something or "something else"
我正在尝试将这些转换为全文引擎兼容的字符串,如下所示：
("engine" AND "2009")
("san francisco" AND "hotel" AND "december" AND "xyz")
("stuff*" "in miami" "1234")
("something" OR "something else")
我有一个非常困难的时间,尝试使用计数引号,空格和插入等,但我的代码看起来像可怕的呕吐物.
有人可以帮忙吗？
解决方法
干得好：
class Program {
static void Main(string[] args) {
// setup some test expressions
List<string> searchExpressions = new List<string>(new string[] {
"engine 2009","\"san francisco\" hotel december xyz","stuff* \"in miami\" 1234 ","something or \"something else\""
});
// display and parse each expression
foreach (string searchExpression in searchExpressions) {
Console.WriteLine(string.Concat(
"User Input: ",searchExpression,"\r\n\tsql Expression: ",ParseSearchExpression(searchExpression),"\r\n"));
}
Console.ReadLine();
}
private static string ParseSearchExpression(string searchExpression) {
// replace all 'spacecharacters' that exists within quotes with character 0
string temp = Regex.Replace(searchExpression,@"""[^""]+""",(MatchEvaluator)delegate(Match m) {
return Regex.Replace(m.Value,@"[\s]","\x00");
});
// split string on any spacecharacter (thus: quoted items will not be splitted)
string[] tokens = Regex.Split(temp,@"[""\s]+",RegexOptions.IgnoreCase | RegexOptions.ExplicitCapture);
// generate result
StringBuilder result = new StringBuilder();
string tokenLast = string.Empty;
foreach (string token in tokens) {
if (token.Length > 0) {
if ((token.Length > 0) && (!token.Equals("AND",StringComparison.OrdinalIgnoreCase))) {
if (result.Length > 0) {
result.Append(tokenLast.Equals("OR",StringComparison.OrdinalIgnoreCase) ? " OR " : " AND ");
}
result.Append("\"").Append(token.Replace("\"","\"\"").Replace("\x00"," ")).Append("\"");
}
tokenLast = token;
}
}
if (result.Length > 0) {
result.Insert(0,"(").Append(")");
}
return result.ToString();
}
}
