JDBC实现增删改查.doc

1. publicclassNoteDAOImplimplementsNoteDAO 2. /增加操作 3. publicvoidinsert(Notenote)throwsException 4. Stringsql=INSERTINTOnote(id,title,author,content)VALUES(note_sequ.nextVal,?,?,?); 5. PreparedStatementpstmt=null; 6. DataBaseConnectiondbc=null; 7. dbc=newDataBaseConnection(); 8. try 9. pstmt=dbc.getConnection().prepareStatement(sql); 10. pstmt.setString(1,note.getTitle(); 11. pstmt.setString(2,note.getAuthor(); 12. pstmt.setString(3,note.getContent(); 13. pstmt.executeUpdate(); 14. pstmt.close(); 15. catch(Exceptione) 16. /System.out.println(e); 17. thrownewException(操作中出现错误！); 18. finally 19. dbc.close(); 20. 21. 22. /修改操作 23. publicvoidupdate(Notenote)throwsException 24. Stringsql=UPDATEnoteSETtitle=?,author=?,content=?WHEREid=?; 25. PreparedStatementpstmt=null; 26. DataBaseConnectiondbc=null; 27. dbc=newDataBaseConnection(); 28. try 29. pstmt=dbc.getConnection().prepareStatement(sql); 30. pstmt.setString(1,note.getTitle(); 31. pstmt.setString(2,note.getAuthor(); 32. pstmt.setString(3,note.getContent(); 33. pstmt.setInt(4,note.getId(); 34. pstmt.executeUpdate(); 35. pstmt.close(); 36. catch(Exceptione) 37. thrownewException(操作中出现错误！); 38. finally 39. dbc.close(); 40. 41. 42. /删除操作 43. publicvoiddelete(intid)throwsException 44. Stringsql=DELETEFROMnoteWHEREid=?; 45. PreparedStatementpstmt=null; 46. DataBaseConnectiondbc=null; 47. dbc=newDataBaseConnection(); 48. try 49. pstmt=dbc.getConnection().prepareStatement(sql); 50. pstmt.setInt(1,id); 51. pstmt.executeUpdate(); 52. pstmt.close(); 53. catch(Exceptione) 54. thrownewException(操作中出现错误！); 55. finally 56. dbc.close(); 57. 58. 59. /按ID查询，主要为更新使用 60. publicNotequeryById(intid)throwsException 61. Notenote=null; 62. Stringsql=SELECTid,title,author,contentFROMnoteWHEREid=?; 63. PreparedStatementpstmt=null; 64. DataBaseConnectiondbc=null; 65. dbc=newDataBaseConnection(); 66. try 67. pstmt=dbc.getConnection().prepareStatement(sql); 68. pstmt.setInt(1,id); 69. ResultSetrs=pstmt.executeQuery(); 70. if(rs.next() 71. note=newNote(); 72. note.setId(rs.getInt(1); 73. note.setTitle(rs.getString(2); 74. note.setAuthor(rs.getString(3); 75. note.setContent(rs.getString(4); 76. 77. rs.close(); 78. pstmt.close(); 79. catch(Exceptione) 80. thrownewException(操作中出现错误！); 81. finally 82. dbc.close(); 83. 84. returnnote; 85. 86. /查询全部 87. publicListqueryAll()throwsException 88. Listall=newArrayList(); 89. Stringsql=SELECTid,title,author,contentFROMnote; 90. PreparedStatementpstmt=null; 91. DataBaseConnectiondbc=null; 92. dbc=newDataBaseConnection(); 93. try 94. pstmt=dbc.getConnection().prepareStatement(sql); 95. ResultSetrs=pstmt.executeQuery(); 96. while(rs.next() 97. Notenote=newNote(); 98. note.setId(rs.getInt(1); 99. note.setTitle(rs.getString(2); 100. note.setAuthor(rs.getString(3); 101. note.setContent(rs.getString(4); 102. all.add(note); 103. 104. rs.close(); 105. pstmt.close(); 106. catch(Exceptione) 107. System.out.println(e); 108. thrownewException(操作中出现错误！); 109. finally 110. dbc.close(); 111. 112. returnall; 113. 114. /模糊查询 115. publicListqueryByLike(Stringcond)throwsException 116. Listall=newArrayList(); 117. Stringsql=SELECTid,title,author,contentFROMnoteWHEREtitleLIKE?orAUTHORLIKE?orCONTENTLIKE?; 118. PreparedStatementpstmt=null; 119. DataBaseConnectiondbc=null; 120. dbc=newDataBaseConnection(); 121. try 122. pstmt=dbc.getConnection().prepareStatement(sql); 123. pstmt.setString(1,%+cond+%); 124. pstmt.setString(2,%+cond+%); 125. pstmt.setString(3,%+cond+%); 126. ResultSetrs=pstmt.executeQuery(); 127. while(rs.next() 128. Notenote=newNote(); 129. note.setId(rs.getInt(1); 130. note.setTitle(rs.getString(2); 131. note.setAuthor(rs.getString(3); 132. note.setContent(rs.getString(4); 133. all.add(note); 134. 135. rs.close(); 136. pstmt.close(); 137