mcs/class/System.Data/System.Data/DataColumn.cs

   1 //
   2 // System.Data.DataColumn.cs
   3 //
   4 // Author:
   5 //   Christopher Podurgiel (cpodurgiel@msn.com)
   6 //   Rodrigo Moya (rodrigo@ximian.com)
   7 //   Daniel Morgan (danmorg@sc.rr.com)
   8 //
   9 // (C) Chris Podurgiel
  10 // (C) Ximian, Inc 2002
  11 //
  12
  13
  14 using System;
  15 using System.ComponentModel;
  16
  17 namespace System.Data
  18 {
  19         /// <summary>
  20         /// Summary description for DataColumn.
  21         /// </summary>
  22         public class DataColumn : MarshalByValueComponent
  23         {
  24                 #region Fields
  25
  26                 private bool allowDBNull = true;
  27                 private bool autoIncrement = false;
  28                 private long autoIncrementSeed = 0;
  29                 private long autoIncrementStep = 1;
  30                 private string caption = null;
  31                 private MappingType columnMapping = MappingType.Element;
  32                 private string columnName = null;
  33                 private Type dataType = null;
  34                 private object defaultValue = null;
  35                 private string expression = null;
  36                 private PropertyCollection extendedProperties = null;
  37                 private int maxLength = -1;
  38                 private string nameSpace = null;
  39                 private int ordinal = -1;
  40                 private string prefix = null;
  41                 private bool readOnly = false;
  42                 private DataTable _table = null;
  43                 private bool unique = false;
  44
  45                 #endregion // Fields
  46
  47                 #region Constructors
  48
  49                 public DataColumn()
  50                 {
  51                 }
  52
  53                 public DataColumn(string columnName): this()
  54                 {
  55                         ColumnName = columnName;
  56                 }
  57
  58                 public DataColumn(string columnName, Type dataType): this(columnName)
  59                 {
  60                         if(dataType == null) {
  61                                 throw new ArgumentNullException();
  62                         }
  63
  64                         DataType = dataType;
  65
  66                 }
  67
  68                 public DataColumn( string columnName, Type dataType,
  69                         string expr): this(columnName, dataType)
  70                 {
  71                         Expression = expr;
  72                 }
  73
  74                 public DataColumn(string columnName, Type dataType,
  75                         string expr, MappingType type): this(columnName, dataType, expr)
  76                 {
  77                         ColumnMapping = type;
  78                 }
  79                 #endregion
  80
  81                 #region Properties
  82
  83                 public bool AllowDBNull
  84                 {
  85                         get {
  86                                 return allowDBNull;
  87                         }
  88                         set {
  89                                 allowDBNull = value;
  90                         }
  91                 }
  92
  93                 /// <summary>
  94                 /// Gets or sets a value indicating whether the column automatically increments the value of the column for new rows added to the table.
  95                 /// </summary>
  96                 /// <remarks>
  97                 ///             If the type of this column is not Int16, Int32, or Int64 when this property is set,
  98                 ///             the DataType property is coerced to Int32. An exception is generated if this is a computed column
  99                 ///             (that is, the Expression property is set.) The incremented value is used only if the row's value for this column,
 100                 ///             when added to the columns collection, is equal to the default value.
 101                 ///     </remarks>
 102                 public bool AutoIncrement
 103                 {
 104                         get {
 105                                 return autoIncrement;
 106                         }
 107                         set {
 108                                 autoIncrement = value;
 109                                 if(autoIncrement == true)
 110                                 {
 111                                         if(Expression != null)
 112                                         {
 113                                                 throw new Exception();
 114                                         }
 115                                         if(Type.GetTypeCode(dataType) != TypeCode.Int16 &&
 116                                            Type.GetTypeCode(dataType) != TypeCode.Int32 &&
 117                                            Type.GetTypeCode(dataType) != TypeCode.Int64)
 118                                         {
 119                                                 Int32 dtInt = new Int32();
 120                                                 dataType = dtInt.GetType();
 121                                         }
 122                                 }
 123                         }
 124                 }
 125
 126                 public long AutoIncrementSeed
 127                 {
 128                         get {
 129                                 return autoIncrementSeed;
 130                         }
 131                         set {
 132                                 autoIncrementSeed = value;
 133                         }
 134                 }
 135
 136                 public long AutoIncrementStep
 137                 {
 138                         get {
 139                                 return autoIncrementStep;
 140                         }
 141                         set {
 142                                 autoIncrementStep = value;
 143                         }
 144                 }
 145
 146                 public string Caption
 147                 {
 148                         get {
 149                                 if(caption == null)
 150                                         return columnName;
 151                                 else
 152                                         return caption;
 153                         }
 154                         set {
 155                                 caption = value;
 156                         }
 157                 }
 158
 159                 public virtual MappingType ColumnMapping
 160                 {
 161                         get {
 162                                 return columnMapping;
 163                         }
 164                         set {
 165                                 columnMapping = value;
 166                         }
 167                 }
 168
 169                 public string ColumnName
 170                 {
 171                         get {
 172                                 return columnName;
 173                         }
 174                         set {
 175                                 columnName = value;
 176                         }
 177                 }
 178
 179                 public Type DataType
 180                 {
 181                         get {
 182                                 return dataType;
 183                         }
 184                         set {
 185                                 if(AutoIncrement == true &&
 186                                    Type.GetTypeCode(value) != TypeCode.Int32)
 187                                 {
 188                                         throw new Exception();
 189                                 }
 190                                 dataType = value;
 191                         }
 192                 }
 193
 194                 /// <summary>
 195                 ///
 196                 /// </summary>
 197                 /// <remarks>When AutoIncrement is set to true, there can be no default value.</remarks>
 198                 public object DefaultValue
 199                 {
 200                         get {
 201                                 return defaultValue;
 202                         }
 203                         set {
 204                                 defaultValue = value;
 205                         }
 206                 }
 207
 208                 public string Expression
 209                 {
 210                         get {
 211                                 return expression;
 212                         }
 213                         set {
 214                                 expression = value;
 215                         }
 216                 }
 217
 218                 public PropertyCollection ExtendedProperties
 219                 {
 220                         get {
 221                                 return extendedProperties;
 222                         }
 223                 }
 224
 225                 public int MaxLength
 226                 {
 227                         get {
 228                                 return maxLength;
 229                         }
 230                         set {
 231                                 maxLength = value;
 232                         }
 233                 }
 234
 235                 public string Namespace
 236                 {
 237                         get {
 238                                 return nameSpace;
 239                         }
 240                         set {
 241                                 nameSpace = value;
 242                         }
 243                 }
 244
 245                 //Need a good way to set the Ordinal when the column is added to a columnCollection.
 246                 public int Ordinal
 247                 {
 248                         get {
 249                                 return ordinal;
 250                         }
 251                 }
 252
 253                 public string Prefix
 254                 {
 255                         get {
 256                                 return prefix;
 257                         }
 258                         set {
 259                                 prefix = value;
 260                         }
 261                 }
 262
 263                 public bool ReadOnly
 264                 {
 265                         get {
 266                                 return readOnly;
 267                         }
 268                         set {
 269                                 readOnly = value;
 270                         }
 271                 }
 272
 273                 public DataTable Table
 274                 {
 275                         get {
 276                                 return _table;
 277                         }
 278                 }
 279
 280                 public bool Unique
 281                 {
 282                         get {
 283                                 return unique;
 284                         }
 285                         set {
 286                                 unique = value;
 287                         }
 288                 }
 289
 290                 #endregion // Properties
 291
 292                 #region Methods
 293
 294                 [MonoTODO]
 295                 protected internal void CheckNotAllowNull() {
 296                 }
 297
 298                 [MonoTODO]
 299                 protected void CheckUnique() {
 300                 }
 301
 302                 [MonoTODO]
 303                 protected internal virtual void
 304                 OnPropertyChanging (PropertyChangedEventArgs pcevent) {
 305                 }
 306
 307                 [MonoTODO]
 308                 protected internal void RaisePropertyChanging(string name) {
 309                 }
 310
 311                 /// <summary>
 312                 /// Gets the Expression of the column, if one exists.
 313                 /// </summary>
 314                 /// <returns>The Expression value, if the property is set;
 315                 /// otherwise, the ColumnName property.</returns>
 316                 [MonoTODO]
 317                 public override string ToString()
 318                 {
 319                         if (expression != null)
 320                                 return expression;
 321
 322                         return columnName;
 323                 }
 324
 325                 [MonoTODO]
 326                 internal void SetTable(DataTable table) {
 327                         _table = table;
 328                         // FIXME: this will get called by DataTable
 329                         // and DataColumnCollection
 330                 }
 331
 332                 #endregion // Methods
 333
 334         }
 335 }