| 1 | /* ============================================================= |
| 2 | * SmallSQL : a free Java DBMS library for the Java(tm) platform |
| 3 | * ============================================================= |
| 4 | * |
| 5 | * (C) Copyright 2004-2006, by Volker Berlin. |
| 6 | * |
| 7 | * Project Info: http://www.smallsql.de/ |
| 8 | * |
| 9 | * This library is free software; you can redistribute it and/or modify it |
| 10 | * under the terms of the GNU Lesser General Public License as published by |
| 11 | * the Free Software Foundation; either version 2.1 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This library is distributed in the hope that it will be useful, but |
| 15 | * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| 16 | * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public |
| 17 | * License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU Lesser General Public |
| 20 | * License along with this library; if not, write to the Free Software |
| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, |
| 22 | * USA. |
| 23 | * |
| 24 | * [Java is a trademark or registered trademark of Sun Microsystems, Inc. |
| 25 | * in the United States and other countries.] |
| 26 | * |
| 27 | * --------------- |
| 28 | * CommandSelect.java |
| 29 | * --------------- |
| 30 | * Author: Volker Berlin |
| 31 | * |
| 32 | */ |
| 33 | package smallsql.database; |
| 34 | |
| 35 | import java.sql.*; |
| 36 | |
| 37 | |
| 38 | class CommandSelect extends Command{ |
| 39 | |
| 40 | private DataSources from; // List of TableResult |
| 41 | private Expression where; |
| 42 | RowSource join; |
| 43 | private Expressions groupBy; |
| 44 | private Expression having; |
| 45 | private Expressions orderBy; |
| 46 | private boolean isAggregateFunction; |
| 47 | private int maxRows; |
| 48 | /** is set if the keyword DISTINCT is used */ |
| 49 | private boolean isDistinct; |
| 50 | |
| 51 | CommandSelect(Logger log){ |
| 52 | super(log); |
| 53 | } |
| 54 | |
| 55 | CommandSelect(Logger log, Expressions columnExpressions){ |
| 56 | super(log, columnExpressions); |
| 57 | } |
| 58 | |
| 59 | |
| 60 | boolean compile(SSConnection con) throws Exception{ |
| 61 | boolean needCompile = false; |
| 62 | if(from != null){ |
| 63 | for(int i=0; i<from.size(); i++){ |
| 64 | DataSource fromEntry = from.get(i); |
| 65 | needCompile |= fromEntry.init( con ); |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | if(join == null){ |
| 70 | join = new NoFromResult(); |
| 71 | from = new DataSources(); |
| 72 | needCompile = true; |
| 73 | } |
| 74 | if(!needCompile) return false; |
| 75 | |
| 76 | for(int i=0; i<columnExpressions.size(); i++){ |
| 77 | Expression col = columnExpressions.get(i); |
| 78 | if(col.getAlias() == null){ |
| 79 | // für Ausdrücke automatische Namen vergeben |
| 80 | col.setAlias("col" + (i+1)); |
| 81 | } |
| 82 | |
| 83 | if(col.getType() != Expression.NAME){ |
| 84 | compileLinkExpressionParams(col); |
| 85 | continue; |
| 86 | } |
| 87 | |
| 88 | ExpressionName expr = (ExpressionName)col; |
| 89 | |
| 90 | if("*".equals( expr.getName() )){ |
| 91 | String tableAlias = expr.getTableAlias(); |
| 92 | if(tableAlias != null){ |
| 93 | // Syntax: tableAlias.* |
| 94 | int t=0; |
| 95 | for(; t<from.size(); t++){ |
| 96 | DataSource fromEntry = from.get(t); |
| 97 | if(tableAlias.equalsIgnoreCase( fromEntry.getAlias() )){ |
| 98 | TableView table = fromEntry.getTableView(); |
| 99 | columnExpressions.remove(i); |
| 100 | i = compileAdd_All_Table_Columns( fromEntry, table, i ) - 1; |
| 101 | break; |
| 102 | } |
| 103 | } |
| 104 | if(t==from.size()) throw Utils.createSQLException( "The column prefix '" + tableAlias + "' does not match with a table name or alias name used in this query" ); |
| 105 | }else{ |
| 106 | // Syntax * |
| 107 | columnExpressions.remove(i); |
| 108 | for(int t=0; t<from.size(); t++){ |
| 109 | DataSource fromEntry = from.get(t); |
| 110 | TableView table = fromEntry.getTableView(); |
| 111 | i = compileAdd_All_Table_Columns( fromEntry, table, i ); |
| 112 | } |
| 113 | i--; |
| 114 | } |
| 115 | }else{ |
| 116 | // not a * Syntax |
| 117 | compileLinkExpressionName( expr ); |
| 118 | } |
| 119 | |
| 120 | } |
| 121 | if(where != null) compileLinkExpression( where ); |
| 122 | if(having != null) compileLinkExpression( having ); |
| 123 | if(orderBy != null) { |
| 124 | for(int i=0; i<orderBy.size(); i++){ |
| 125 | compileLinkExpression( orderBy.get(i)); |
| 126 | } |
| 127 | } |
| 128 | if(groupBy != null){ |
| 129 | for(int i=0; i<groupBy.size(); i++){ |
| 130 | compileLinkExpression( groupBy.get(i) ); |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | if(join instanceof Join){ |
| 135 | compileJoin( (Join)join ); |
| 136 | } |
| 137 | |
| 138 | if(where != null){ |
| 139 | join = new Where( join, where ); |
| 140 | } |
| 141 | |
| 142 | if(isGroupResult()) { |
| 143 | join = new GroupResult( this, join, groupBy, having, orderBy); |
| 144 | if(having != null){ |
| 145 | join = new Where( join, having ); |
| 146 | } |
| 147 | } |
| 148 | |
| 149 | if(isDistinct){ |
| 150 | join = new Distinct( join, columnExpressions ); |
| 151 | } |
| 152 | |
| 153 | if(orderBy != null){ |
| 154 | join = new SortedResult( join, orderBy ); |
| 155 | } |
| 156 | |
| 157 | return true; |
| 158 | } |
| 159 | |
| 160 | |
| 161 | /** |
| 162 | * If this ResultSet is use any type of grouping. This means that GroupResult need create and that |
| 163 | * the ResultSet is not updataable. |
| 164 | */ |
| 165 | final boolean isGroupResult(){ |
| 166 | return groupBy != null || having != null || isAggregateFunction; |
| 167 | } |
| 168 | |
| 169 | |
| 170 | /** |
| 171 | * Set the link between the Named Expression and the Table object |
| 172 | * in the condition. |
| 173 | * If there are cascade Joins then follow the tree with a recursion. |
| 174 | */ |
| 175 | private void compileJoin( Join join ) throws Exception{ |
| 176 | if(join.condition != null) compileLinkExpressionParams( join.condition ); |
| 177 | if(join.left instanceof Join){ |
| 178 | compileJoin( (Join)join.left ); |
| 179 | } |
| 180 | if(join.right instanceof Join){ |
| 181 | compileJoin( (Join)join.right ); |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | |
| 186 | private void compileLinkExpression( Expression expr) throws Exception{ |
| 187 | if(expr.getType() == Expression.NAME) |
| 188 | compileLinkExpressionName( (ExpressionName)expr); |
| 189 | else compileLinkExpressionParams( expr ); |
| 190 | } |
| 191 | |
| 192 | |
| 193 | /** |
| 194 | * setzt die Verbindung einer named Expresion zur Table und Spaltenindex |
| 195 | * This means a colun name in the SQL statement is link to it table source |
| 196 | */ |
| 197 | private void compileLinkExpressionName( ExpressionName expr ) throws Exception{ |
| 198 | String tableAlias = expr.getTableAlias(); |
| 199 | if(tableAlias != null){ |
| 200 | int t=0; |
| 201 | for(; t<from.size(); t++){ |
| 202 | DataSource fromEntry = from.get(t); |
| 203 | if(tableAlias.equalsIgnoreCase( fromEntry.getAlias() )){ |
| 204 | TableView table = fromEntry.getTableView(); |
| 205 | int colIdx = table.findColumnIdx( expr.getName() ); |
| 206 | if(colIdx>=0){ |
| 207 | // Column gefunden und Table zur Expression setzen |
| 208 | expr.setFrom( fromEntry, colIdx, table ); |
| 209 | break; |
| 210 | }else |
| 211 | throw Utils.createSQLException("Invalid column name '" + expr.getName() + "'."); |
| 212 | } |
| 213 | } |
| 214 | if(t==from.size()) throw Utils.createSQLException( "The column prefix '" + tableAlias + "' does not match with a table name or alias name used in this query" ); |
| 215 | }else{ |
| 216 | // column name ohne table name |
| 217 | int t=0; |
| 218 | for(; t<from.size(); t++){ |
| 219 | DataSource fromEntry = from.get(t); |
| 220 | TableView table = fromEntry.getTableView(); |
| 221 | int colIdx = table.findColumnIdx( expr.getName() ); |
| 222 | if(colIdx>=0){ |
| 223 | // Column gefunden und Table zur Expression setzen |
| 224 | expr.setFrom( fromEntry, colIdx, table ); |
| 225 | break; |
| 226 | } |
| 227 | } |
| 228 | if(t>=from.size()){ |
| 229 | throw Utils.createSQLException("Invalid column name '" + expr.getName() + "'."); |
| 230 | } |
| 231 | } |
| 232 | compileLinkExpressionParams(expr); |
| 233 | } |
| 234 | |
| 235 | |
| 236 | private void compileLinkExpressionParams(Expression expr) throws Exception{ |
| 237 | // SubExpresion überprüfen |
| 238 | Expression[] params = expr.getParams(); |
| 239 | isAggregateFunction = isAggregateFunction || expr.getType() >= Expression.GROUP_BEGIN; |
| 240 | if(params != null){ |
| 241 | for(int k=0; k<params.length; k++){ |
| 242 | Expression param = params[k]; |
| 243 | int type = param.getType(); |
| 244 | isAggregateFunction = isAggregateFunction || type >= Expression.GROUP_BEGIN; |
| 245 | if(type == Expression.NAME) |
| 246 | compileLinkExpressionName( (ExpressionName)param ); |
| 247 | else compileLinkExpressionParams( param ); |
| 248 | } |
| 249 | } |
| 250 | } |
| 251 | |
| 252 | |
| 253 | private final int compileAdd_All_Table_Columns( DataSource fromEntry, TableView table, int position){ |
| 254 | for(int k=0; k<table.columns.size(); k++){ |
| 255 | ExpressionName expr = new ExpressionName( table.columns.get(k).getName() ); |
| 256 | expr.setFrom( fromEntry, k, table ); |
| 257 | columnExpressions.add( position++, expr ); |
| 258 | } |
| 259 | return position; |
| 260 | } |
| 261 | |
| 262 | |
| 263 | /** |
| 264 | * The main method to execute this Command and create a ResultSet. |
| 265 | */ |
| 266 | void executeImpl(SSConnection con, SSStatement st) throws Exception{ |
| 267 | compile(con); |
| 268 | if((st.rsType == ResultSet.TYPE_SCROLL_INSENSITIVE || st.rsType == ResultSet.TYPE_SCROLL_SENSITIVE) && |
| 269 | !join.isScrollable()){ |
| 270 | join = new Scrollable(join); |
| 271 | } |
| 272 | join.execute(); |
| 273 | rs = new SSResultSet( st, this ); |
| 274 | } |
| 275 | |
| 276 | |
| 277 | /** |
| 278 | * Is used from ResultSet.beforeFirst(). |
| 279 | * |
| 280 | */ |
| 281 | void beforeFirst() throws Exception{ |
| 282 | join.beforeFirst(); |
| 283 | } |
| 284 | |
| 285 | |
| 286 | /** |
| 287 | * Is used from ResultSet.isBeforeFirst(). |
| 288 | */ |
| 289 | boolean isBeforeFirst() throws SQLException{ |
| 290 | return join.isBeforeFirst(); |
| 291 | } |
| 292 | |
| 293 | |
| 294 | /** |
| 295 | * Is used from ResultSet.isFirst(). |
| 296 | */ |
| 297 | boolean isFirst() throws SQLException{ |
| 298 | return join.isFirst(); |
| 299 | } |
| 300 | |
| 301 | |
| 302 | /** |
| 303 | * Is used from ResultSet.first(). |
| 304 | */ |
| 305 | boolean first() throws Exception{ |
| 306 | return join.first(); |
| 307 | } |
| 308 | |
| 309 | |
| 310 | /** |
| 311 | * Is used from ResultSet.previous(). |
| 312 | */ |
| 313 | boolean previous() throws Exception{ |
| 314 | return join.previous(); |
| 315 | } |
| 316 | |
| 317 | |
| 318 | /** |
| 319 | * move to the next row. |
| 320 | * @return true if the next row valid |
| 321 | * @throws Exception |
| 322 | */ |
| 323 | boolean next() throws Exception{ |
| 324 | if(maxRows > 0 && join.getRow() >= maxRows){ |
| 325 | join.afterLast(); |
| 326 | return false; |
| 327 | } |
| 328 | return join.next(); |
| 329 | } |
| 330 | |
| 331 | |
| 332 | /** |
| 333 | * Is used from ResultSet.last(). |
| 334 | */ |
| 335 | final boolean last() throws Exception{ |
| 336 | if(maxRows > 0){ |
| 337 | return join.absolute(maxRows); |
| 338 | } |
| 339 | return join.last(); |
| 340 | } |
| 341 | |
| 342 | |
| 343 | /** |
| 344 | * Is used from ResultSet.afterLast(). |
| 345 | */ |
| 346 | final void afterLast() throws Exception{ |
| 347 | join.afterLast(); |
| 348 | } |
| 349 | |
| 350 | |
| 351 | /** |
| 352 | * Is used from ResultSet.isLast(). |
| 353 | */ |
| 354 | boolean isLast() throws Exception{ |
| 355 | return join.isLast(); |
| 356 | } |
| 357 | |
| 358 | |
| 359 | /** |
| 360 | * Is used from ResultSet.isAfterLast(). |
| 361 | */ |
| 362 | boolean isAfterLast() throws Exception{ |
| 363 | return join.isAfterLast(); |
| 364 | } |
| 365 | |
| 366 | |
| 367 | /** |
| 368 | * Is used from ResultSet.absolute(). |
| 369 | */ |
| 370 | final boolean absolute(int row) throws Exception{ |
| 371 | return join.absolute(row); |
| 372 | } |
| 373 | |
| 374 | |
| 375 | /** |
| 376 | * Is used from ResultSet.relative(). |
| 377 | */ |
| 378 | final boolean relative(int rows) throws Exception{ |
| 379 | return join.relative(rows); |
| 380 | } |
| 381 | |
| 382 | |
| 383 | /** |
| 384 | * Is used from ResultSet.afterLast(). |
| 385 | */ |
| 386 | final int getRow() throws Exception{ |
| 387 | int row = join.getRow(); |
| 388 | if(maxRows > 0 && row > maxRows) return 0; |
| 389 | return row; |
| 390 | } |
| 391 | |
| 392 | |
| 393 | final void updateRow(SSConnection con, Expression[] newRowSources) throws SQLException{ |
| 394 | int savepoint = con.getSavepoint(); |
| 395 | try{ |
| 396 | //loop through all tables of this ResultSet |
| 397 | for(int t=0; t<from.size(); t++){ |
| 398 | TableViewResult result = TableViewResult.getTableViewResult( from.get(t) ); |
| 399 | TableView table = result.getTableView(); |
| 400 | Columns tableColumns = table.columns; |
| 401 | int count = tableColumns.size(); |
| 402 | |
| 403 | // order the new Values after it position in the table |
| 404 | Expression[] updateValues = new Expression[count]; |
| 405 | boolean isUpdateNeeded = false; |
| 406 | for(int i=0; i<columnExpressions.size(); i++){ |
| 407 | Expression src = newRowSources[i]; |
| 408 | if(src != null && (!(src instanceof ExpressionValue) || !((ExpressionValue)src).isEmpty())){ |
| 409 | Expression col = columnExpressions.get(i); |
| 410 | if(!col.isDefinitelyWritable()) |
| 411 | throw Utils.createSQLException("Column " + i + " is read only."); |
| 412 | ExpressionName exp = (ExpressionName)col; |
| 413 | if(table == exp.getTable()){ |
| 414 | updateValues[exp.getColumnIndex()] = src; |
| 415 | isUpdateNeeded = true; |
| 416 | continue; |
| 417 | } |
| 418 | } |
| 419 | } |
| 420 | |
| 421 | // save the new values if there are new value for this table |
| 422 | if(isUpdateNeeded){ |
| 423 | result.updateRow(updateValues); |
| 424 | } |
| 425 | } |
| 426 | }catch(Throwable e){ |
| 427 | con.rollback(savepoint); |
| 428 | throw Utils.createSQLException(e); |
| 429 | }finally{ |
| 430 | if(con.getAutoCommit()) con.commit(); |
| 431 | } |
| 432 | } |
| 433 | |
| 434 | final void insertRow(SSConnection con, Expression[] newRowSources) throws SQLException{ |
| 435 | if(from.size() > 1) |
| 436 | throw Utils.createSQLException("InsertRow not supported on joins."); |
| 437 | if(from.size() == 0) |
| 438 | throw Utils.createSQLException("InsertRow need a FROM expression."); |
| 439 | |
| 440 | int savepoint = con.getSavepoint(); |
| 441 | try{ |
| 442 | TableViewResult result = TableViewResult.getTableViewResult( from.get(0) ); |
| 443 | TableView table = result.getTableView(); |
| 444 | Columns tabColumns = table.columns; |
| 445 | int count = tabColumns.size(); |
| 446 | |
| 447 | // order the new Values after it position in the table |
| 448 | Expression[] updateValues = new Expression[count]; |
| 449 | if(newRowSources != null){ |
| 450 | for(int i=0; i<columnExpressions.size(); i++){ |
| 451 | Expression src = newRowSources[i]; |
| 452 | if(src != null && (!(src instanceof ExpressionValue) || !((ExpressionValue)src).isEmpty())){ |
| 453 | Expression rsColumn = columnExpressions.get(i); // Column of the ResultSet |
| 454 | if(!rsColumn.isDefinitelyWritable()) |
| 455 | throw Utils.createSQLException("Column " + i + " is read only."); |
| 456 | ExpressionName exp = (ExpressionName)rsColumn; |
| 457 | if(table == exp.getTable()){ |
| 458 | updateValues[exp.getColumnIndex()] = src; |
| 459 | continue; |
| 460 | } |
| 461 | } |
| 462 | updateValues[i] = null; |
| 463 | } |
| 464 | } |
| 465 | |
| 466 | // save the new values if there are new value for this table |
| 467 | result.insertRow(updateValues); |
| 468 | }catch(Throwable e){ |
| 469 | con.rollback(savepoint); |
| 470 | throw Utils.createSQLException(e); |
| 471 | }finally{ |
| 472 | if(con.getAutoCommit()) con.commit(); |
| 473 | } |
| 474 | } |
| 475 | |
| 476 | final void deleteRow(SSConnection con) throws SQLException{ |
| 477 | int savepoint = con.getSavepoint(); |
| 478 | try{ |
| 479 | if(from.size() > 1) |
| 480 | throw Utils.createSQLException("DeleteRow not supported on joins."); |
| 481 | if(from.size() == 0) |
| 482 | throw Utils.createSQLException("DeleteRow need a FROM expression."); |
| 483 | TableViewResult.getTableViewResult( from.get(0) ).deleteRow(); |
| 484 | }catch(Throwable e){ |
| 485 | con.rollback(savepoint); |
| 486 | throw Utils.createSQLException(e); |
| 487 | }finally{ |
| 488 | if(con.getAutoCommit()) con.commit(); |
| 489 | } |
| 490 | } |
| 491 | |
| 492 | |
| 493 | /** |
| 494 | * The returning index start at 0. |
| 495 | */ |
| 496 | public int findColumn(String columnName) throws SQLException { |
| 497 | Expressions columns = columnExpressions; |
| 498 | // FIXME performance |
| 499 | for(int i=0; i<columns.size(); i++){ |
| 500 | if(columnName.equalsIgnoreCase(columns.get(i).getAlias())) |
| 501 | return i; |
| 502 | } |
| 503 | throw Utils.createSQLException("Column '"+columnName+"' not found." ); |
| 504 | } |
| 505 | |
| 506 | |
| 507 | /** |
| 508 | * Set if the keyword DISTINCT occur in the SELECT expession. |
| 509 | */ |
| 510 | final void setDistinct(boolean distinct){ |
| 511 | this.isDistinct = distinct; |
| 512 | } |
| 513 | |
| 514 | |
| 515 | /** |
| 516 | * Set the RowSource expression from the FROM clause. |
| 517 | * The Simples case is only a Table (TableResult) |
| 518 | */ |
| 519 | final void setSource(RowSource join){ |
| 520 | this.join = join; |
| 521 | } |
| 522 | |
| 523 | /** |
| 524 | * List of all Tables and Views. |
| 525 | * This is needed to replace the table aliases in the columnExpressions with the real soures. |
| 526 | */ |
| 527 | final void setFrom( DataSources from ){ |
| 528 | this.from = from; |
| 529 | } |
| 530 | |
| 531 | /** |
| 532 | * Is used from CommandSelect, CommandDelete and CommandUpdate |
| 533 | * @param where |
| 534 | */ |
| 535 | final void setWhere( Expression where ){ |
| 536 | this.where = where; |
| 537 | } |
| 538 | |
| 539 | final void setGroup(Expressions group){ |
| 540 | this.groupBy = group; |
| 541 | } |
| 542 | |
| 543 | final void setHaving(Expression having){ |
| 544 | this.having = having; |
| 545 | } |
| 546 | |
| 547 | final void setOrder(Expressions order){ |
| 548 | this.orderBy = order; |
| 549 | } |
| 550 | |
| 551 | |
| 552 | final void setMaxRows(int max){ |
| 553 | maxRows = max; |
| 554 | } |
| 555 | |
| 556 | |
| 557 | final int getMaxRows(){ |
| 558 | return maxRows; |
| 559 | } |
| 560 | } |