C# DBConnection.ExecuteReaderCommand方法代码示例

        /// <summary>
        /// Executes this command using the specified database connection to get a data reader and then executes the specified method with the reader.
        /// </summary>
        public void Execute( DBConnection cn, Action<DbDataReader> readerMethod )
        {
            var command = cn.DatabaseInfo.CreateCommand();
            command.CommandText =
                "SELECT{0} {1} ".FormatWith(
                    cacheQueryInDatabase && cn.DatabaseInfo.QueryCacheHint.Any() ? " {0}".FormatWith( cn.DatabaseInfo.QueryCacheHint ) : "",
                    StringTools.ConcatenateWithDelimiter( ", ", selectExpressions.ToArray() ) ) + fromClause;

            if( conditions.Any() ) {
                command.CommandText += " WHERE ";
                var first = true;
                var paramNumber = 0;
                foreach( var condition in conditions ) {
                    if( !first )
                        command.CommandText += " AND ";
                    first = false;
                    condition.AddToCommand( command, cn.DatabaseInfo, InlineUpdate.GetParamNameFromNumber( paramNumber++ ) );
                }
            }

            command.CommandText = command.CommandText.ConcatenateWithSpace( orderByClause );
            cn.ExecuteReaderCommand( command, readerMethod );
        }

        internal static void Generate( DBConnection cn, TextWriter writer, string baseNamespace, Database database )
        {
            writer.WriteLine( "namespace " + baseNamespace + "." + database.SecondaryDatabaseName + "Sequences {" );

            var cmd = cn.DatabaseInfo.CreateCommand();
            cmd.CommandText = "SELECT * FROM USER_SEQUENCES";
            cn.ExecuteReaderCommand( cmd,
                                     reader => {
                                         while( reader.Read() ) {
                                             var sequenceName = reader[ "SEQUENCE_NAME" ].ToString();
                                             writer.WriteLine();
                                             writer.WriteLine( "public class " + sequenceName + " {" );
                                             writer.WriteLine( "public static decimal GetNextValue() {" );
                                             writer.WriteLine( "DbCommand cmd = " + DataAccessStatics.GetConnectionExpression( database ) + ".DatabaseInfo.CreateCommand();" );
                                             writer.WriteLine( "cmd.CommandText = \"SELECT " + sequenceName + ".NEXTVAL FROM DUAL\";" );
                                             writer.WriteLine( "return (decimal)" + DataAccessStatics.GetConnectionExpression( database ) + ".ExecuteScalarCommand( cmd );" );
                                             writer.WriteLine( "}" );
                                             writer.WriteLine( "}" );
                                         }
                                     } );

            writer.WriteLine();
            writer.WriteLine( "}" );
        }

        private void deleteAndReCreateUser( DBConnection cn )
        {
            // Delete the existing user and schema.
            deleteUser( cn );

            // Re-create the user with the minimally required privileges.
            executeLongRunningCommand( cn, "CREATE USER " + info.UserAndSchema + " IDENTIFIED BY " + info.Password + " ACCOUNT UNLOCK" );

            // This allows the user to connect to the database.
            executeLongRunningCommand( cn, "GRANT CREATE SESSION TO " + info.UserAndSchema );

            // This overrides all tablespace quotas for this user, which default to 0 and therefore prevent the user from creating any tables or other objects.
            executeLongRunningCommand( cn, "GRANT UNLIMITED TABLESPACE TO " + info.UserAndSchema );

            executeLongRunningCommand( cn, "GRANT CREATE PROCEDURE TO " + info.UserAndSchema ); // Necessary for RLE Personnel secondary databases.
            executeLongRunningCommand( cn, "GRANT CREATE SEQUENCE TO " + info.UserAndSchema );
            executeLongRunningCommand( cn, "GRANT CREATE TABLE TO " + info.UserAndSchema );
            executeLongRunningCommand( cn, "GRANT CREATE TRIGGER TO " + info.UserAndSchema ); // Necessary for RLE Personnel secondary databases.
            executeLongRunningCommand( cn, "GRANT READ, WRITE ON DIRECTORY " + dataPumpOracleDirectoryName + " TO " + info.UserAndSchema );

            // Get all tablespaces currently in the database.
            var command = cn.DatabaseInfo.CreateCommand();
            command.CommandText = "SELECT tablespace_name FROM dba_tablespaces";
            var currentTableSpaces = new List<string>();
            cn.ExecuteReaderCommand(
                command,
                reader => {
                    while( reader.Read() )
                        currentTableSpaces.Add( reader.GetString( 0 ).ToLower() );
                } );

            // Create necessary tablespaces that don't already exist.
            foreach( var nonExistentTs in latestTableSpaces.Select( s => s.ToLower() ).Except( currentTableSpaces ) ) {
                var tableSpaceFolderPath = EwlStatics.CombinePaths( ConfigurationStatics.RedStaplerFolderPath, "Oracle Tablespaces" );
                Directory.CreateDirectory( tableSpaceFolderPath );
                executeLongRunningCommand(
                    cn,
                    "CREATE TABLESPACE " + nonExistentTs + " DATAFILE '" + EwlStatics.CombinePaths( tableSpaceFolderPath, nonExistentTs + ".dbf" ) + "' SIZE 100M" );
            }
        }

 /// <summary>
 /// Executes this procedure against the specified database connection to get a data reader and then executes the specified method with the reader.
 /// </summary>
 public void ExecuteReader( DBConnection cn, Action<DbDataReader> readerMethod )
 {
     var cmd = cn.DatabaseInfo.CreateCommand();
     setupDbCommand( cmd, cn.DatabaseInfo );
     cn.ExecuteReaderCommand( cmd, readerMethod );
 }