如何进行不区分大小写的搜索。 Xamarin sqlite

Posted 2023-04-13

【中文标题】如何进行不区分大小写的搜索。 Xamarin sqlite

【英文标题】：How to do a case insesitive search. Xamarin sqlite

【发布时间】：2021-02-18 05:22:18

【问题描述】：

下面是我的代码。我正在尝试对描述进行不区分大小写的搜索，它也需要是部分文本搜索，这就是我使用“包含”的原因。

public Task<List<AssetTable>> SearchAssets(int ID, string text)

    return _database.Table<AssetTable>()
        .Where(i =>
            (
                i.ParentID == ID ||
                i.Site == ID ||
                i.Location == ID ||
                i.SubLocation == ID ||
                i.PGroup == ID
            ) &&
            i.TempCode == "ASSET" &&
            //i.Description.Contains(text)
            i.Description.Contains(text, StringComparison.CurrentCultureIgnoreCase)
        )
        .ToListAsync();

注释的行是我之前的行，但它区分大小写，虽然当前行确实编译和运行，但在搜索文本时出现运行时异常。

[ERROR] FATAL UNHANDLED EXCEPTION: SQLite.SQLiteException: near "?": syntax error
  at SQLite.SQLite3.Prepare2 (SQLitePCL.sqlite3 db, System.String query) [0x0001b] in <84b9c9e630fa45bd8ac799333976ebbf>:0 
  at SQLite.SQLiteCommand.Prepare () [0x00011] in <84b9c9e630fa45bd8ac799333976ebbf>:0 
  at SQLite.SQLiteCommand+<ExecuteDeferredQuery>d__12`1[T].MoveNext () [0x00060] in <84b9c9e630fa45bd8ac799333976ebbf>:0 
  at System.Collections.Generic.List`1[T].AddEnumerable (System.Collections.Generic.IEnumerable`1[T] enumerable) [0x00059] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/Common/src/CoreLib/System/Collections/Generic/List.cs:1108
  at System.Collections.Generic.List`1[T]..ctor (System.Collections.Generic.IEnumerable`1[T] collection) [0x00062] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/Common/src/CoreLib/System/Collections/Generic/List.cs:87 
  at System.Linq.Enumerable.ToList[TSource] (System.Collections.Generic.IEnumerable`1[T] source) [0x0000e] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.Linq/src/System/Linq/ToCollection.cs:30 
  at SQLite.SQLiteCommand.ExecuteQuery[T] () [0x0001c] in <84b9c9e630fa45bd8ac799333976ebbf>:0 
  at SQLite.TableQuery`1[T].ToList () [0x0000b] in <84b9c9e630fa45bd8ac799333976ebbf>:0 
  at SQLite.AsyncTableQuery`1[T].<ToListAsync>b__11_0 (SQLite.SQLiteConnectionWithLock conn) [0x00000] in <84b9c9e630fa45bd8ac799333976ebbf>:0 
  at SQLite.AsyncTableQuery`1+<>c__DisplayClass2_0`1[T,U].<ReadAsync>b__0 () [0x0001d] in <84b9c9e630fa45bd8ac799333976ebbf>:0 
  at System.Threading.Tasks.Task`1[TResult].InnerInvoke () [0x0000f] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corert/src/System.Private.CoreLib/src/System/Threading/Tasks/Future.cs:534 
  at System.Threading.Tasks.Task.Execute () [0x00000] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corert/src/System.Private.CoreLib/src/System/Threading/Tasks/Task.cs:2319 

不知道我做错了什么，希望能得到帮助和建议以提供更好的解决方案。

【参考方案1】：

可能还有其他/更好的解决方案，但我首先要尝试的是这个

i.Description.ToLower().Contains(text.ToLower())

【讨论】：

不敢相信我没想过要尝试。如果有比将它们都转换为小写更好的解决方案，我会密切关注，但这肯定会给我一个解决方案，谢谢。 :)