class/Npgsql/Npgsql/NpgsqlServices.cs

   1 #if ENTITIES
   2 using System;
   3 using System.Collections.Generic;
   4 using System.Data.Common;
   5 using System.Xml;
   6 using System.Data.Common.CommandTrees;
   7 using System.Data.Metadata.Edm;
   8 using Npgsql.SqlGenerators;
   9
  10 namespace Npgsql
  11 {
  12     internal class NpgsqlServices : DbProviderServices
  13     {
  14         private static readonly NpgsqlServices _instance = new NpgsqlServices();
  15
  16         public static NpgsqlServices Instance
  17         {
  18             get { return _instance; }
  19         }
  20
  21         protected override DbCommandDefinition CreateDbCommandDefinition(DbProviderManifest providerManifest, DbCommandTree commandTree)
  22         {
  23             return CreateCommandDefinition(CreateDbCommand(commandTree));
  24         }
  25
  26         private DbCommand CreateDbCommand(DbCommandTree commandTree)
  27         {
  28             if (commandTree == null)
  29                 throw new ArgumentNullException("commandTree");
  30
  31             DbCommand command = NpgsqlFactory.Instance.CreateCommand();
  32
  33             foreach (KeyValuePair<string, TypeUsage> parameter in commandTree.Parameters)
  34             {
  35                 DbParameter dbParameter = command.CreateParameter();
  36                 dbParameter.ParameterName = parameter.Key;
  37                 command.Parameters.Add(dbParameter);
  38             }
  39
  40             TranslateCommandTree(commandTree, command);
  41
  42             return command;
  43         }
  44
  45         private void TranslateCommandTree(DbCommandTree commandTree, DbCommand command)
  46         {
  47             SqlBaseGenerator sqlGenerator = null;
  48
  49             DbQueryCommandTree select;
  50             DbInsertCommandTree insert;
  51             DbUpdateCommandTree update;
  52             DbDeleteCommandTree delete;
  53             if ((select = commandTree as DbQueryCommandTree) != null)
  54             {
  55                 sqlGenerator = new SqlSelectGenerator(select);
  56             }
  57             else if ((insert = commandTree as DbInsertCommandTree) != null)
  58             {
  59                 sqlGenerator = new SqlInsertGenerator(insert);
  60             }
  61             else if ((update = commandTree as DbUpdateCommandTree) != null)
  62             {
  63                 sqlGenerator = new SqlUpdateGenerator(update);
  64             }
  65             else if ((delete = commandTree as DbDeleteCommandTree) != null)
  66             {
  67                 sqlGenerator = new SqlDeleteGenerator(delete);
  68             }
  69             else
  70             {
  71                 // TODO: get a message (unsupported DbCommandTree type)
  72                 throw new ArgumentException();
  73             }
  74
  75             sqlGenerator.BuildCommand(command);
  76         }
  77
  78         protected override string GetDbProviderManifestToken(DbConnection connection)
  79         {
  80             if (connection == null)
  81                 throw new ArgumentNullException("connection");
  82             // TODO: used to use connection.ServerVersion
  83             // that doesn't work with a closed connection.
  84             bool openedConnection = false;
  85             try
  86             {
  87                 if (connection.State != System.Data.ConnectionState.Open)
  88                 {
  89                     connection.Open();
  90                     openedConnection = true;
  91                 }
  92                 return connection.ServerVersion;
  93             }
  94             finally
  95             {
  96                 if (openedConnection)
  97                 {
  98                     connection.Close();
  99                 }
 100             }
 101         }
 102
 103         protected override DbProviderManifest GetDbProviderManifest(string versionHint)
 104         {
 105             if (versionHint == null)
 106                 throw new ArgumentNullException("versionHint");
 107             return new NpgsqlProviderManifest(versionHint);
 108         }
 109     }
 110 }
 111
 112 #endif