mcs/class/Mono.Data.PostgreSqlClient/Mono.Data.PostgreSqlClient/ParmUtil.cs

   1 //\r
   2 // ParmUtil.cs - utility to bind variables in a SQL statement to parameters in C# code\r
   3 //               This is in the PostgreSQL .NET Data provider in Mono\r
   4 //\r
   5 // Author: \r
   6 //    Daniel Morgan <danmorg@sc.rr.com>\r
   7 //\r
   8 // (c)copyright 2002 Daniel Morgan\r
   9 //\r
  10 \r
  11 // comment DEBUG_ParmUtil for production, for debug messages, uncomment\r
  12 //#define DEBUG_ParmUtil\r
  13 \r
  14 using System;\r
  15 using System.Data;\r
  16 using System.Text;\r
  17 \r
  18 namespace Mono.Data.PostgreSqlClient {\r
  19 \r
  20         enum PostgresBindVariableCharacter {\r
  21                 Semicolon,\r
  22                 At,\r
  23                 QuestionMark\r
  24         }\r
  25 \r
  26         public class ParmUtil {\r
  27 \r
  28                 private string sql = "";\r
  29                 private string resultSql = "";\r
  30                 private PgSqlParameterCollection parmsCollection = null;\r
  31                 \r
  32                 static private PostgresBindVariableCharacter PgbindChar = PostgresBindVariableCharacter.Semicolon;\r
  33                 static char bindChar;\r
  34 \r
  35                 // static constructor\r
  36                 static ParmUtil() {\r
  37                         switch(PgbindChar) {\r
  38                         case PostgresBindVariableCharacter.Semicolon:\r
  39                                 bindChar = ':';\r
  40                                 break;\r
  41                         case PostgresBindVariableCharacter.At:\r
  42                                 bindChar = '@';\r
  43                                 break;\r
  44                         case PostgresBindVariableCharacter.QuestionMark:\r
  45                                 // this doesn't have named parameters,\r
  46                                 // they must be in order\r
  47                                 bindChar = '?';\r
  48                                 break;\r
  49                         }\r
  50                 }\r
  51                                 \r
  52                 public ParmUtil(string query, PgSqlParameterCollection parms) {\r
  53                         sql = query;\r
  54                         parmsCollection = parms;\r
  55                 }\r
  56                 \r
  57                 public string ResultSql {\r
  58                         get {\r
  59                                 return resultSql;\r
  60                         }\r
  61                 }\r
  62 \r
  63                 // TODO: currently only works for input variables,\r
  64                 //       need to do input/output, output, and return\r
  65                 public string ReplaceWithParms() {\r
  66 \r
  67                         StringBuilder result = new StringBuilder();\r
  68                         char[] chars = sql.ToCharArray();\r
  69                         bool bStringConstFound = false;\r
  70 \r
  71                         for(int i = 0; i < chars.Length; i++) {\r
  72                                 if(chars[i] == '\'') {\r
  73                                         if(bStringConstFound == true)\r
  74                                                 bStringConstFound = false;\r
  75                                         else\r
  76                                                 bStringConstFound = true;\r
  77 \r
  78                                         result.Append(chars[i]);\r
  79                                 }\r
  80                                 else if(chars[i] == bindChar && \r
  81                                         bStringConstFound == false) {\r
  82 #if DEBUG_ParmUtil\r
  83                                         Console.WriteLine("Bind Variable character found...");\r
  84 #endif                                  \r
  85                                         StringBuilder parm = new StringBuilder();\r
  86                                         i++;\r
  87                                         while(i <= chars.Length) {\r
  88                                                 char ch;\r
  89                                                 if(i == chars.Length)\r
  90                                                         ch = ' '; // a space\r
  91                                                 else\r
  92                                                         ch = chars[i];\r
  93 \r
  94 #if DEBUG_ParmUtil                                              \r
  95                                                 Console.WriteLine("Is char Letter or digit?");\r
  96 #endif                                          \r
  97                                                 if(Char.IsLetterOrDigit(ch)) {\r
  98 #if DEBUG_ParmUtil\r
  99                                                         Console.WriteLine("Char IS letter or digit. " + \r
 100                                                                 "Now, append char to parm StringBuilder");\r
 101 #endif\r
 102                                                         parm.Append(ch);\r
 103                                                 }\r
 104                                                 else {\r
 105 #if DEBUG_ParmUtil\r
 106                                                         Console.WriteLine("Char is NOT letter or char. " + \r
 107                                                                 "thus we got rest of bind variable name. ");\r
 108                                                                 \r
 109                                                         // replace bind variable placeholder \r
 110                                                         // with data value constant\r
 111                                                         Console.WriteLine("parm StringBuilder to string p...");\r
 112 #endif\r
 113                                                         string p = parm.ToString();\r
 114 #if DEBUG_ParmUtil\r
 115                                                         Console.WriteLine("calling BindReplace...");\r
 116 #endif                                                  \r
 117                                                         bool found = BindReplace(result, p);\r
 118 #if DEBUG_ParmUtil\r
 119                                                         Console.WriteLine("    Found = " + found);\r
 120 #endif\r
 121                                                         if(found == true)\r
 122                                                                 break;\r
 123                                                         else {                                          \r
 124                                                                 // *** Error Handling\r
 125                                                                 Console.WriteLine("Error: parameter not found: " + p);\r
 126                                                                 return "";\r
 127                                                         }\r
 128                                                 }\r
 129                                                 i++;\r
 130                                         }\r
 131                                         i--;\r
 132                                 }\r
 133                                 else \r
 134                                         result.Append(chars[i]);\r
 135                         }\r
 136                         \r
 137                         resultSql = result.ToString();\r
 138                         return resultSql;\r
 139                 }\r
 140 \r
 141                 public bool BindReplace (StringBuilder result, string p) {\r
 142                         // bind variable\r
 143                         bool found = false;\r
 144 \r
 145 #if DEBUG_ParmUtil\r
 146                         Console.WriteLine("Does the parmsCollection contain the parameter???: " + p);\r
 147 #endif\r
 148                         if(parmsCollection.Contains(p) == true) {\r
 149                                 // parameter found\r
 150 #if DEBUG_ParmUtil\r
 151                                 Console.WriteLine("Parameter Found: " + p);\r
 152 #endif\r
 153                                 PgSqlParameter prm = parmsCollection[p];\r
 154 \r
 155 #if DEBUG_ParmUtil                                                                                                                                      \r
 156                                 // DEBUG \r
 157                                 Console.WriteLine("          Value: " + prm.Value);\r
 158                                 Console.WriteLine("      Direction: " + prm.Direction);\r
 159 #endif\r
 160                                 // convert object to string and place\r
 161                                 // into SQL\r
 162                                 if(prm.Direction == ParameterDirection.Input) {\r
 163                                         string strObj = PostgresHelper.\r
 164                                                 ObjectToString(prm.DbType, \r
 165                                                                 prm.Value);\r
 166                                         result.Append(strObj);\r
 167                                 }\r
 168                                 else\r
 169                                         result.Append(bindChar + p);\r
 170 \r
 171                                 found = true;\r
 172                         }\r
 173                         return found;\r
 174                 }\r
 175         }\r
 176 }\r