CLR实现SQL正则表达式.doc

T-SQL 正则表达式(CLR 实现)创建程序集 ClrRegExClass.cs，并使用 C:WindowsMicrosoft.NETFrameworkv2.0.50727csc.exe /target:library ClrRegExClass.cs 编译为 ClrRegExClass.DLL 文件。C# codeusing System;using System.Data;using System.Data.SqlClient;using System.Data.SqlTypes;using Microsoft.SqlServer.Server;using System.Text.RegularExpressions;public partial class RegExp/ 验证字符串中是否包含与指定的匹配模式一致的字符串 SqlFunction(IsDeterministic = true, IsPrecise = true) public static SqlBoolean RegExIsMatch(SqlString expression, SqlString pattern) return new SqlBoolean(Regex.IsMatch(expression.ToString(), pattern.ToString(); / 替换字符串中与指定的匹配模式一致的字符串 SqlFunction(IsDeterministic = true, IsPrecise = true) public static SqlString RegExReplace(SqlString expression, SqlString pattern, SqlString replacement) return new SqlString(Regex.Replace(expression.ToString(), pattern.ToString(), replacement.ToString(); / 提取字符串中与指定的匹配模式一致的字符串 SqlFunction(IsDeterministic = true, IsPrecise = true) public static SqlString RegExSubstring(SqlString expression, SqlString pattern, SqlInt32 position, SqlInt32 occurrence) if (expression.ToString().Length position) return new SqlString(); if (position = 0) position = 1; if (occurrence = 0) occurrence = 1; Match m = Regex.Match(expression.ToString().Substring(int) position - 1),pattern.ToString(); for (int i = 1; i (int)occurrence; i+) m = m.NextMatch(); if (!m.Success) return new SqlString(); return new SqlString(m.ToString(); / 计算字符串中与指定的匹配模式一致的字符串的数目 SqlFunction(IsDeterministic = true, IsPrecise = true) public static SqlInt32 RegExCount(SqlString expression, SqlString pattern, SqlInt32 position) if (expression.ToString().Length position) return 0; if (position = 0) position = 1; MatchCollection ms = Regex.Matches(expression.ToString().Substring(int)position - 1), pattern.ToString(); return new SqlInt32(ms.Count); / 查找字符串中与指定的匹配模式一致的字符串的位置 SqlFunction(IsDeterministic = true, IsPrecise = true) public static SqlInt32 RegExIndex(SqlString expression, SqlString pattern, SqlInt32 position, SqlInt32 occurrence) if (expression.ToString().Length position) return 0; if (position = 0) position = 1; if (occurrence = 0) occurrence = 1; Match m = Regex.Match(expression.ToString().Substring(int)position - 1), pattern.ToString(); for (int i = 1; i (int)occurrence; i+) m = m.NextMatch(); if (!m.Success) return 0; return new SqlInt32(m.Index + 1); 将程序集 ClrRegExClass.DLL 导入 SQL Server，并创建相应的函数。SQL code/ 启用 SQL Server 的 CLR 支持exec sp_configure clr enabled,1;goreconfigurego/ 导入程序集if exists (select * from sys.assemblies where name=RegExp) drop assembly RegExp;gocreate assembly RegExp authorization dbofrom fullpathClrRegExClass.dllwith permission_set=safe;go/ 创建函数/ expression 为输入的字符串；pattern 为正则表达式；/ position 为字符串开始的位置；occurrence 为与指定的匹配模式一致的字符串出现的次数if object_id(dbo.regex_ismatch,FS) is not null drop function dbo.regex_ismatch;gocreate function dbo.regex_ismatch(expression nvarchar(max), pattern nvarchar(max)returns bit with returns null on null inputas external name RegExp.RegExp.RegExIsMatch;go- 验证字符串是否以 server 开头- select dbo.regex_ismatch(server.database.schema.object,server);if object_id(dbo.regex_replace,FS) is not null drop function dbo.regex_replace;gocreate function dbo.regex_replace(expression nvarchar(max), pattern nvarchar(max), replacement nvarchar(max)returns nvarchar(max) with returns null on null inputas external name RegExp.RegExp.RegExReplace;go- 将字符串中 . 替换为 .- select dbo.regex_replace(server.database.schema.object,(w*),$1);if object_id(dbo.regex_substring,FS) is not null drop function dbo.regex_substring;gocreate function dbo.regex_substring(expression nvarchar(max), pattern nvarchar(max), position int, occurrence int)returns nvarchar(max) with returns null on null inputas external name RegExp.RegExp.RegExSubstring;go- 提取字符串中与 . 模式匹配的第二次出现的字符串- select dbo.regex_substring(server.database.schema.object,w*,1,2);if object_id(dbo.regex_count,FS) is not null drop function dbo.regex_count;gocreate function dbo.regex_count(expression nvarchar(max), pattern nvarchar(max), position int)returns int with returns null on null inputas external name RegExp.RegExp.RegExCount;go- 计算字符串中与 . 模式匹配的字符串的数目- select dbo.regex_count(server.database.schema.object,w*,1);if object_id(dbo.regex_index,FS) is not null drop function dbo.regex_index;gocreate function dbo.regex_index(expression nvarchar(max), pattern nvarchar(max), position int, occurrence int)returns int with returns null on null inputas external name RegExp.RegExp.RegExIndex;go- 查询字符串中与 . 模式匹配的第二次出现的字符串开始的位置- select dbo.regex_index(server.database.schema.object,w*,1,2);以前我在网上看到一个更好的，比这个实用多了，楼主你这个RegExCount和RegExIndex一般不会用到，RegExSubstring更是不可能去使用，无意义的函数。看来看去只有一个RegExIsMatch会需要用到。好了，别说我不厚道，贴一下更强大的CLR函数（不是我写的），其中RegExGroups函数是精华，非常实用：C# codeusing System;using System.Data;using System.Data.SqlClient;using System.Data.SqlTypes;using Microsoft.SqlServer.Server;using System.Text.RegularExpressions;using System.Collections;using System.Diagnostics.CodeAnalysis;public static partial class UserDefinedFunctions public static readonly RegexOptions Options = RegexOptions.IgnorePatternWhitespace | RegexOptions.Singleline; SqlFunction public static SqlBoolean RegexMatch( SqlChars input, SqlString pattern) Regex regex = new Regex( pattern.Value, Options ); return regex.IsMatch( new string( input.Value ) ); SqlFunction public static SqlChars RegexGroup( SqlChars input, SqlString pattern, SqlString name) Regex regex = new Regex(pattern.Value, Options); Match match = regex.Match(new string(input.Value); return match.Success ? new SqlChars(match.Groupsname.Value.Value) : SqlChars.Null; internal class MatchNode private int _index; public int Index get return _index; private string _value; public string Value get return _value; public MatchNode(int index, string value) _index = index; _value = value; internal class MatchIterator : IEnumerable private Regex _regex; private string _input; public MatchIterator(string input, string pattern) _regex = new Regex(pattern, UserDefinedFunctions.Options); _input = input; public IEnumerator GetEnumerator() int index = 0; Match current = null; do current = (current = null) ? _regex.Match(_input) : current.NextMatch(); if (current.Success) yield return new MatchNode(+index, current.Value); while (current.Success); SqlFunction(FillRowMethodName = FillMatchRow, TableDefinition = Index int,Text nvarchar(max) public static IEnumerable RegexMatches(SqlChars input, SqlString pattern) return new MatchIterator(new string(input.Value), pattern.Value); SuppressMessage(Microsoft.Design, CA1021:AvoidOutParameters) public static void FillMatchRow(object data, out SqlInt32 index, out SqlChars text) MatchNode node = (MatchNode)data; index = new SqlInt32(node.Index); text = new SqlChars(node.Value.ToCharArray(); internal class GroupNode private int _index; public int Index get return _index; private string _name; public string Name get return _name; private string _value; public string Value get return _value; public GroupNode(int index, string group, string value) _index = index; _name = group; _value = value; internal class GroupIterator : IEnumerable private Regex _regex; private string _input; public GroupIterator(string input, string pattern) _regex = new Regex(pattern, UserDefinedFunctions.Options); _input = input; public IEnumerator GetEnumerator() int index = 0; Match current = null; string names = _regex.GetGroupNames(); do index+; current = (current = null) ? _regex.Match(_input) : current.NextMatch(); if (current.Success) foreach (string name in names) Group group = current.Groupsname; if (group.Success) yield return new GroupNode( index, name, group.Value); while (current.Success); SqlFunction(FillRowMethodName = FillGroupRow, TableDefinition = Index int,Group nvarchar(max),Text nvarchar(max) public static IEnumerable RegexGroups(SqlChars inpu