Source Code for Module library.pyjamas.gears.database.Database

  1  """ 
  2  * Copyright 2008 Google Inc. 
  3  * 
  4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not 
  5  * use this file except in compliance with the License. You may obtain a copy of 
  6  * the License at 
  7  * 
  8  * http:#www.apache.org/licenses/LICENSE-2.0 
  9  * 
 10  * Unless required by applicable law or agreed to in writing, software 
 11  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 
 12  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 
 13  * License for the specific language governing permissions and limitations under 
 14  * the License. 
 15  """ 
 16   
 17   
 18   
 19   
 20   
 21   
 22  """* 
 23  * An in-browser SQL database. Gears provides a SQL database using SQLite 
 24  * syntax. For details, see the <a href="http:#www.sqlite.org/lang.html">SQLite 
 25  * syntax.</a> 
 26  * 
 27  * Note that this class (and its related classes) intentionally do NOT implement 
 28  * the JDBC interface, since the database provided by Gears does necessarily 
 29  * implement all those semantics. It may be possible to add a JDBC layer on top 
 30  * of this, but it's unclear whether that would really be useful. 
 31  """ 
 32   
 33  from __pyjamas__ import JS 
 34   
 35 -class GearsDatabase: 
 36   
 37 -    def __init__(self, db): 
 38   
 39          self.db = db 
 40   
 41      """* 
 42      * Closes the database connection, if any, currently associated with this 
 43      * Database instance. Calling Database.close() is not required. 
 44      * 
 45      * @throws DatabaseException if an error occurs 
 46      """ 
 47 -    def close(self): 
 48          #try: 
 49              self.uncheckedClose() 
 50          #except ex: 
 51          #    raise DatabaseException(ex.getDescription(), ex) 
 52   
 53      """* 
 54      * Executes the specified SQL statement and returns a {@link ResultSet} 
 55      * containing the results. 
 56      * 
 57      * Substitute zero or more bind parameters from <code>args</code> into 
 58      * <code>sqlStatement</code> and execute the resulting SQL statement. There 
 59      * must be exactly as many items in <code>args</code> as there are ? place 
 60      * holders in <code>sqlStatement</code>. <code>args</code> can be omitted 
 61      * if there are no place holders. The results of executing the statement are 
 62      * returned in a ResultSet. 
 63      * 
 64      * Note that if multiple processes (including Workers) attempt to write to the 
 65      * database at the same time, one can fail. It is up to the application to 
 66      * retry in these situations. 
 67      * 
 68      * @param sqlStatement SQL statement to execute; may use '?' place holders 
 69      * @param args values for the place holders in the <code>sqlStatement</code> 
 70      * @return {@link ResultSet} associated with the SQL statement 
 71      * @throws DatabaseException if the SQL statement fails or if multiple Workers 
 72      *           attempt to write to the database at the same time 
 73      """ 
 74 -    def execute(self, sqlStatement, *args): 
 75          #try: 
 76              if args: 
 77                  return self.execute_args(sqlStatement, args) 
 78              else: 
 79                  return self.execute_args(sqlStatement) 
 80          #except ex: 
 81          #    raise DatabaseException(ex.getDescription(), ex) 
 82   
 83      """* 
 84      * Returns the ID of the last row inserted into a table. This is a global 
 85      * counter, and is unique over all rows in all tables. 
 86      * 
 87      * @return the ID of the last row inserted, or 0 if no rows have been inserted 
 88      *         on this connection 
 89      """ 
 90 -    def getLastInsertRowId(self): 
 91          JS(""" 
 92          return this['db']['lastInsertRowId']; 
 93          """) 
 94   
 95      """* 
 96      * Returns the number of database rows that were changed, inserted, or deleted 
 97      * by the most recently completed INSERT, UPDATE, or DELETE statement on this 
 98      * Database instance. 
 99      * 
100      * Note that an unconstrained delete of all rows in a table (DELETE FROM 
101      * table) will return zero rather than the number of rows that were originally 
102      * present in the table; if you need the number of rows, use DELETE FROM table 
103      * WHERE 1 instead, though be aware that this is slower than an unconstrained 
104      * delete. 
105      * 
106      * @return the number of database rows impacted by the last INSERT, UPDATE or * 
107      *         DELETE statement on this Database instance 
108      """ 
109 -    def getRowsAffected(self): 
110          JS(""" 
111          return this['db']['rowsAffected']; 
112          """) 
113   
114      """* 
115      * Opens a database with the specified <code>name</code>. Note that this 
116      * name is local to the application's origin. 
117      * 
118      * @param name name of the database (None - Opens an unnamed database.) 
119      """ 
120 -    def open(self, name=None): 
121          if name is None: 
122              JS(" this['db']['open'](); ") 
123          else: 
124              JS(" this['db']['open'](@{{name}}); ") 
125   
126   
127 -    def execute_args(self, sqlStatement, args): 
128          JS(""" 
129          if (typeof @{{args}} == 'undefined') { 
130              return this['db']['execute'](@{{sqlStatement}}); 
131          } else { 
132              return this['db']['execute'](@{{sqlStatement}}, @{{args}}['l']); 
133          } 
134          """) 
135   
136   
137 -    def uncheckedClose(self): 
138          JS(""" 
139          this['db']['close'](); 
140          """) 
141