{"id":940,"date":"2011-01-28T01:00:00","date_gmt":"2011-01-27T16:00:00","guid":{"rendered":"https:\/\/ecoop.net\/memo\/2011-01-28-1.html"},"modified":"2013-09-15T00:19:28","modified_gmt":"2013-09-14T15:19:28","slug":"2011-01-28-1","status":"publish","type":"post","link":"https:\/\/www.ecoop.net\/memo\/archives\/2011-01-28-1.html","title":{"rendered":"SQLiteOpenHelper \u3067\u30c6\u30fc\u30d6\u30eb\u30ab\u30e9\u30e0\u5909\u66f4\u6642\u306b\u30c7\u30fc\u30bf\u3092\u5f15\u304d\u7d99\u3050"},"content":{"rendered":"

\nSQLiteOpenHelper \u306e\u5b9f\u88c5\u30b5\u30f3\u30d7\u30eb\u3067\u3059\u3002
\nonUpgrade() \u306e\u5b9f\u88c5\u306f DROP TABLE \u30af\u30a8\u30ea\u3092\u5b9f\u884c\u3059\u308b\u306e\u304c\u7c21\u5358\u306a\u306e\u3067\u3059\u304c\u3001
\n\u305d\u308c\u3060\u3068DB\u30d0\u30fc\u30b8\u30e7\u30f3\u30a2\u30c3\u30d7\u3054\u3068\u306b\u30c7\u30fc\u30bf\u304c\u30ea\u30bb\u30c3\u30c8\u3055\u308c\u3066\u3057\u307e\u3044\u307e\u3059\u3002
\n 
\n\u30d0\u30fc\u30b8\u30e7\u30f3\u30a2\u30c3\u30d7\u3067\u30ab\u30e9\u30e0\u8ffd\u52a0\u3001\u524a\u9664\u3092\u884c\u3063\u305f\u6642\u3082\u5171\u901a\u30ab\u30e9\u30e0\u306b\u3064\u3044\u3066\u306f\u5f15\u304d\u7d99\u3052\u308b\u3088\u3046\u306b\u3001\u3053\u3061\u3089<\/a>\u306e\u56de\u7b54\u3092\u53c2\u8003\u306b\u5b9f\u88c5\u3057\u3066\u307f\u307e\u3057\u305f\u3002<\/p>\n

\n<\/p>\n

import java.util.ArrayList;
\nimport java.util.Arrays;
\nimport java.util.List;
\n 
\nimport android.content.Context;
\nimport android.database.Cursor;
\nimport android.database.sqlite.SQLiteDatabase;
\nimport android.database.sqlite.SQLiteDatabase.CursorFactory;
\nimport android.database.sqlite.SQLiteOpenHelper;
\n 
\nclass DatabaseHelper extends SQLiteOpenHelper {
\n\/**
\n * DB\u30d5\u30a1\u30a4\u30eb\u540d
\n *\/
\nprivate static final String DATABASE_NAME = “sample.db”;
\n\/**
\n * DB\u30d0\u30fc\u30b8\u30e7\u30f3
\n * (\u65e2\u5b58\u306eDB\u3068\u30d0\u30fc\u30b8\u30e7\u30f3\u5024\u304c\u7570\u306a\u308b\u6642\u3060\u3051 onUpgrade()\u304c\u547c\u3070\u308c\u308b)
\n *\/
\nprivate static final int DATABASE_VERSION = 1;
\n\/**
\n * \u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf
\n *\/
\npublic DatabaseHelper(Context context) {
\n\tsuper(context, DATABASE_NAME, null, DATABASE_VERSION);
\n}
\n 
\n@Override
\npublic void onCreate(SQLiteDatabase db) {
\n\tdb.execSQL(“CREATE TABLE table1 (”
\n\t\t\t+ “name text NOT NULL, ”
\n\t\t\t+ “birthdate INTEGER NOT NULL”
\n\t\t\t+ “)”);
\n}
\n 
\n@Override
\npublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
\n\t\/\/ \u6307\u5b9a\u3057\u305f\u30c6\u30fc\u30d6\u30eb\u306e\u30ab\u30e9\u30e0\u69cb\u6210\u3092\u30c1\u30a7\u30c3\u30af\u3057\u3001
\n\t\/\/ \u540c\u540d\u306e\u30ab\u30e9\u30e0\u306b\u3064\u3044\u3066\u306f\u30a2\u30c3\u30d7\u30b0\u30ec\u30fc\u30c9\u5f8c\u3082\u30c7\u30fc\u30bf\u3092\u5f15\u304d\u7d99\u304e\u307e\u3059\u3002
\n\t\/\/ \u540c\u540d\u306e\u30ab\u30e9\u30e0\u3067\u578b\u306b\u4e92\u63db\u6027\u304c\u306a\u3044\u5834\u5408\u306f\u30a8\u30e9\u30fc\u306b\u306a\u308b\u306e\u3067\u6ce8\u610f\u3002<\/p>\n

\t\/\/ \u66f4\u65b0\u5bfe\u8c61\u306e\u30c6\u30fc\u30d6\u30eb
\n\tfinal String targetTable = “table1”;
\n\tdb.beginTransaction();
\n\ttry {
\n\t\t\/\/ \u5143\u30ab\u30e9\u30e0\u4e00\u89a7
\n\t\tfinal List<String> columns = getColumns(db, targetTable);
\n\t\t\/\/ \u521d\u671f\u5316
\n\t\tdb.execSQL(“ALTER TABLE ” + targetTable + ” RENAME TO temp_”
\n\t\t\t\t+ targetTable);
\n\t\tonCreate(db);
\n\t\t\/\/ \u65b0\u30ab\u30e9\u30e0\u4e00\u89a7
\n\t\tfinal List<String> newColumns = getColumns(db, targetTable);
\n 
\n\t\t\/\/ \u5909\u5316\u3057\u306a\u3044\u30ab\u30e9\u30e0\u306e\u307f\u62bd\u51fa
\n\t\tcolumns.retainAll(newColumns);
\n 
\n\t\t\/\/ \u5171\u901a\u30c7\u30fc\u30bf\u3092\u79fb\u3059\u3002(OLD\u306b\u3057\u304b\u5b58\u5728\u3057\u306a\u3044\u3082\u306e\u306f\u6368\u3066\u3089\u308c, NEW\u306b\u3057\u304b\u5b58\u5728\u3057\u306a\u3044\u3082\u306e\u306fNULL\u306b\u306a\u308b)
\n\t\tfinal String cols = join(columns, “,”);
\n\t\tdb.execSQL(String.format(
\n\t\t\t\t“INSERT INTO %s (%s) SELECT %s from temp_%s”, targetTable,
\n\t\t\t\tcols, cols, targetTable));
\n\t\t\/\/ \u7d42\u4e86\u51e6\u7406
\n\t\tdb.execSQL(“DROP TABLE temp_” + targetTable);
\n\t\tdb.setTransactionSuccessful();
\n\t} finally {
\n\t\tdb.endTransaction();
\n\t}
\n}
\n 
\n\/**
\n * \u6307\u5b9a\u3057\u305f\u30c6\u30fc\u30d6\u30eb\u306e\u30ab\u30e9\u30e0\u540d\u30ea\u30b9\u30c8\u3092\u53d6\u5f97\u3059\u308b\u3002
\n *
\n * @param db
\n * @param tableName
\n * @return \u30ab\u30e9\u30e0\u540d\u306e\u30ea\u30b9\u30c8
\n *\/
\nprivate static List<String> getColumns(SQLiteDatabase db, String tableName) {
\n\tList<String> ar = null;
\n\tCursor c = null;
\n\ttry {
\n\t\tc = db.rawQuery(“SELECT * FROM ” + tableName + ” LIMIT 1″, null);
\n\t\tif (c != null) {
\n\t\t\tar = new ArrayList<String>(Arrays.asList(c.getColumnNames()));
\n\t\t}
\n\t} finally {
\n\t\tif (c != null)
\n\t\t\tc.close();
\n\t}
\n\treturn ar;
\n}
\n 
\n\/**
\n * \u6587\u5b57\u5217\u3092\u4efb\u610f\u306e\u533a\u5207\u308a\u6587\u5b57\u3067\u9023\u7d50\u3059\u308b\u3002
\n *
\n * @param list
\n * \u6587\u5b57\u5217\u306e\u30ea\u30b9\u30c8
\n * @param delim
\n * \u533a\u5207\u308a\u6587\u5b57
\n * @return \u9023\u7d50\u5f8c\u306e\u6587\u5b57\u5217
\n *\/
\nprivate static String join(List<String> list, String delim) {
\n\tfinal StringBuilder buf = new StringBuilder();
\n\tfinal int num = list.size();
\n\tfor (int i = 0; i < num; i++) {
\n\t\tif (i != 0)
\n\t\t\tbuf.append(delim);
\n\t\tbuf.append((String) list.get(i));
\n\t}
\n\treturn buf.toString();
\n}
\n 
\n}\n<\/p><\/blockquote>\n

SQLiteOpenHelper<\/a>(Android Developers)
\nSQLiteOpenHelper onUpgrade() Confusion Android<\/a>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

SQLiteOpenHelper \u306e\u5b9f\u88c5\u30b5\u30f3\u30d7\u30eb\u3067\u3059\u3002 onUpgrade() \u306e\u5b9f\u88c5\u306f DROP TABLE \u30af\u30a8\u30ea\u3092\u5b9f\u884c\u3059\u308b\u306e\u304c\u7c21\u5358\u306a\u306e\u3067\u3059\u304c\u3001 \u305d\u308c\u3060\u3068DB\u30d0\u30fc\u30b8\u30e7\u30f3\u30a2\u30c3\u30d7\u3054\u3068\u306b\u30c7\u30fc\u30bf\u304c\u30ea\u30bb\u30c3\u30c8\u3055\u308c\u3066\u3057\u307e\u3044\u307e\u3059\u3002 … \u7d9a\u304d\u3092\u8aad\u3080 SQLiteOpenHelper \u3067\u30c6\u30fc\u30d6\u30eb\u30ab\u30e9\u30e0\u5909\u66f4\u6642\u306b\u30c7\u30fc\u30bf\u3092\u5f15\u304d\u7d99\u3050<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[85],"tags":[65,41],"class_list":["post-940","post","type-post","status-publish","format-standard","hentry","category-android-dev","tag-android","tag-sqlite"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.ecoop.net\/memo\/wp-json\/wp\/v2\/posts\/940","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ecoop.net\/memo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ecoop.net\/memo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ecoop.net\/memo\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ecoop.net\/memo\/wp-json\/wp\/v2\/comments?post=940"}],"version-history":[{"count":0,"href":"https:\/\/www.ecoop.net\/memo\/wp-json\/wp\/v2\/posts\/940\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ecoop.net\/memo\/wp-json\/wp\/v2\/media?parent=940"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecoop.net\/memo\/wp-json\/wp\/v2\/categories?post=940"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecoop.net\/memo\/wp-json\/wp\/v2\/tags?post=940"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}