Source for java.sql.ResultSetMetaData

   1: /* ResultSetMetaData.java -- Returns information about the ResultSet
   2:    Copyright (C) 1999, 2000, 2002, 2006 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package java.sql;
  40: 
  41: /**
  42:  * This interface provides a mechanism for obtaining information about
  43:  * the columns that are present in a <code>ResultSet</code>.
  44:  *
  45:  * <p> Note that in this class column indices start at 1, not 0.</p>
  46:  *
  47:  * @author Aaron M. Renn (arenn@urbanophile.com)
  48:  */
  49: public interface ResultSetMetaData
  50: {
  51:   /**
  52:    * The column does not allow NULL's.
  53:    */
  54:   int columnNoNulls = 0;
  55: 
  56:   /**
  57:    * The column allows NULL's.
  58:    */
  59:   int columnNullable = 1;
  60: 
  61:   /**
  62:    * It is unknown whether or not the column allows NULL's.
  63:    */
  64:   int columnNullableUnknown = 2;
  65: 
  66:   /**
  67:    * This method returns the number of columns in the result set.
  68:    *
  69:    * @return The number of columns in the result set.
  70:    * @exception SQLException If an error occurs.
  71:    */
  72:   int getColumnCount() throws SQLException;
  73: 
  74:   /**
  75:    * This method test whether or not the column is an auto-increment column.
  76:    * Auto-increment columns are read-only.
  77:    *
  78:    * @param columnIndex The index of the column to test.
  79:    * @return <code>true</code> if the column is auto-increment, <code>false</code>
  80:    *         otherwise.
  81:    * @exception SQLException If an error occurs.
  82:    */
  83:   boolean isAutoIncrement(int columnIndex) throws SQLException;
  84: 
  85:   /**
  86:    * This method tests whether or not a column is case sensitive in its values.
  87:    *
  88:    * @param columnIndex The index of the column to test.
  89:    * @return <code>true</code> if the column value is case sensitive,
  90:    *         <code>false</code> otherwise.
  91:    * @exception SQLException If an error occurs.
  92:    */
  93:   boolean isCaseSensitive(int columnIndex) throws SQLException;
  94: 
  95:   /**
  96:    * This method tests whether not the specified column can be used in
  97:    * a WHERE clause.
  98:    *
  99:    * @param columnIndex The index of the column to test.
 100:    * @return <code>true</code> if the column may be used in a WHERE clause,
 101:    *         <code>false</code> otherwise.
 102:    * @exception SQLException If an error occurs.
 103:    */
 104:   boolean isSearchable(int columnIndex) throws SQLException;
 105: 
 106:   /**
 107:    * This method tests whether or not the column stores a monetary value.
 108:    *
 109:    * @param columnIndex The index of the column to test.
 110:    * @return <code>true</code> if the column contains a monetary value,
 111:    *         <code>false</code> otherwise.
 112:    * @exception SQLException If an error occurs.
 113:    */
 114:   boolean isCurrency(int columnIndex) throws SQLException;
 115: 
 116:   /**
 117:    * This method returns a value indicating whether or not the specified
 118:    * column may contain a NULL value.
 119:    *
 120:    * @param columnIndex The index of the column to test.
 121:    * @return A constant indicating whether or not the column can contain NULL,
 122:    *         which will be one of <code>columnNoNulls</code>,
 123:    *         <code>columnNullable</code>, or <code>columnNullableUnknown</code>.
 124:    * @exception SQLException If an error occurs.
 125:    */
 126:   int isNullable(int columnIndex) throws SQLException;
 127: 
 128:   /**
 129:    * This method tests whether or not the value of the specified column
 130:    * is signed or unsigned.
 131:    *
 132:    * @param columnIndex The index of the column to test.
 133:    * @return <code>true</code> if the column value is signed, <code>false</code>
 134:    *         otherwise.
 135:    * @exception SQLException If an error occurs.
 136:    */
 137:   boolean isSigned(int columnIndex) throws SQLException;
 138: 
 139:   /**
 140:    * This method returns the maximum number of characters that can be used
 141:    * to display a value in this column.
 142:    *
 143:    * @param columnIndex The index of the column to check.
 144:    * @return The maximum number of characters that can be used to display a
 145:    *         value for this column.
 146:    * @exception SQLException If an error occurs.
 147:    */
 148:   int getColumnDisplaySize(int columnIndex) throws SQLException;
 149: 
 150:   /**
 151:    * This method returns a string that should be used as a caption for this
 152:    * column for user display purposes.
 153:    *
 154:    * @param columnIndex The index of the column to check.
 155:    * @return A display string for the column.
 156:    * @exception SQLException If an error occurs.
 157:    */
 158:   String getColumnLabel(int columnIndex) throws SQLException;
 159: 
 160:   /**
 161:    * This method returns the name of the specified column.
 162:    *
 163:    * @param columnIndex The index of the column to return the name of.
 164:    * @return The name of the column.
 165:    * @exception SQLException If an error occurs.
 166:    */
 167:   String getColumnName(int columnIndex) throws SQLException;
 168: 
 169:   /**
 170:    * This method returns the name of the schema that contains the specified
 171:    * column.
 172:    *
 173:    * @param columnIndex The index of the column to check the schema name for.
 174:    * @return The name of the schema that contains the column.
 175:    * @exception SQLException If an error occurs.
 176:    */
 177:   String getSchemaName(int columnIndex) throws SQLException;
 178: 
 179:   /**
 180:    * This method returns the precision of the specified column, which is the
 181:    * number of decimal digits it contains.
 182:    *
 183:    * @param columnIndex The index of the column to check the precision on.
 184:    * @return The precision of the specified column.
 185:    * @exception SQLException If an error occurs.
 186:    */
 187:   int getPrecision(int columnIndex) throws SQLException;
 188: 
 189:   /**
 190:    * This method returns the scale of the specified column, which is the
 191:    * number of digits to the right of the decimal point.
 192:    *
 193:    * @param columnIndex The index column to check the scale of.
 194:    * @return The scale of the column.
 195:    * @exception SQLException If an error occurs.
 196:    */
 197:   int getScale(int columnIndex) throws SQLException;
 198: 
 199:   /**
 200:    * This method returns the name of the table containing the specified
 201:    * column.
 202:    *
 203:    * @param columnIndex The index of the column to check the table name for.
 204:    * @return The name of the table containing the column.
 205:    * @exception SQLException If an error occurs.
 206:    */
 207:   String getTableName(int columnIndex) throws SQLException;
 208: 
 209:   /**
 210:    * This method returns the name of the catalog containing the specified
 211:    * column.
 212:    *
 213:    * @param columnIndex The index of the column to check the catalog name for.
 214:    * @return The name of the catalog containing the column.
 215:    * @exception SQLException If an error occurs.
 216:    */
 217:   String getCatalogName(int columnIndex) throws SQLException;
 218: 
 219:   /**
 220:    * This method returns the SQL type of the specified column.  This will
 221:    * be one of the constants from <code>Types</code>.
 222:    *
 223:    * @param columnIndex The index of the column to check the SQL type of.
 224:    * @return The SQL type for this column.
 225:    * @exception SQLException If an error occurs.
 226:    * @see Types
 227:    */
 228:   int getColumnType(int columnIndex) throws SQLException;
 229: 
 230:   /**
 231:    * This method returns the name of the SQL type for this column.
 232:    *
 233:    * @param columnIndex The index of the column to check the SQL type name for.
 234:    * @return The name of the SQL type for this column.
 235:    * @exception SQLException If an error occurs.
 236:    */
 237:   String getColumnTypeName(int columnIndex) throws SQLException;
 238: 
 239:   /**
 240:    * This method tests whether or not the specified column is read only.
 241:    *
 242:    * @param columnIndex The index of the column to check.
 243:    * @return <code>true</code> if the column is read only, <code>false</code>
 244:    *         otherwise.
 245:    * @exception SQLException If an error occurs.
 246:    */
 247:   boolean isReadOnly(int columnIndex) throws SQLException;
 248: 
 249:   /**
 250:    * This method tests whether or not the column may be writable.  This
 251:    * does not guarantee that a write will be successful.
 252:    *
 253:    * @param columnIndex The index of the column to check for writability.
 254:    * @return <code>true</code> if the column may be writable,
 255:    *         <code>false</code> otherwise.
 256:    * @exception SQLException If an error occurs.
 257:    */
 258:   boolean isWritable(int columnIndex) throws SQLException;
 259: 
 260:   /**
 261:    * This method tests whether or not the column is writable.  This
 262:    * does guarantee that a write will be successful.
 263:    *
 264:    * @param columnIndex The index of the column to check for writability.
 265:    * @return <code>true</code> if the column is writable,
 266:    *         <code>false</code> otherwise.
 267:    * @exception SQLException If an error occurs.
 268:    */
 269:   boolean isDefinitelyWritable(int columnIndex) throws SQLException;
 270: 
 271:   /**
 272:    * This method returns the name of the Java class which will be used to
 273:    * create objects representing the data in this column.
 274:    *
 275:    * @param columnIndex The index of the column to check.
 276:    * @return The name of the Java class that will be used for values in
 277:    *         this column.
 278:    * @exception SQLException If an error occurs.
 279:    */
 280:   String getColumnClassName(int columnIndex) throws SQLException;
 281: }