[英]Updating an entire row (containing multiple columns) within a sqlite database created
[英]Updating multiple columns in a certain row SQL LITE
我有4种方法来更新某一行中数据的单独部分。 (我这样做是因为我是SQ Lite和Android的新手)。 我如何将所有这些浓缩为一种方法?
public void updateInt(int id,String newName, String oldName){
SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
String query = "UPDATE " + TABLE_NAME + " SET " + COL2 +
" = '" + newName + "' WHERE " + COL1 + " = '" + id + "'" +
" AND " + COL2 + " = '" + oldName + "'";
sqLiteDatabase.execSQL(query);
}
public void updateAuth(int id,String newAuth, String oldAuth){
SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
String query = "UPDATE " + TABLE_NAME + " SET " + COL3 +
" = '" + newAuth + "' WHERE " + COL1 + " = '" + id + "'" +
" AND " + COL3 + " = '" + oldAuth + "'";
sqLiteDatabase.execSQL(query);
}
public void updateUser(int id,String newUser, String oldUser){
SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
String query = "UPDATE " + TABLE_NAME + " SET " + COL5 +
" = '" + newUser + "' WHERE " + COL1 + " = '" + id + "'" +
" AND " + COL5 + " = '" + oldUser + "'";
sqLiteDatabase.execSQL(query);
}
public void updateLocation(int id,String newLocation, String oldLocation){
SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
String query = "UPDATE " + TABLE_NAME + " SET " + COL4 +
" = '" + newLocation + "' WHERE " + COL1 + " = '" + id + "'" +
" AND " + COL4 + " = '" + oldLocation + "'";
sqLiteDatabase.execSQL(query);
}
我会保留原样。
由于每个表达式在不同的行中设置不同的内容(所有WHERE
条件都不同),因此它实际上无法合并。
使用SQLitedatbase
update
便捷方法,可以使用:-
public void updateAll(int id,
String newName,
String newAuth,
String newUser,
String newLocation) {
ContentValues cv = new ContentValues();
cv.put(COL2,newName);
cv.put(COL3,newAuth);
cv.put(COL4,newLocation);
cv.put(COL5,newUser);
SqliteDatabase sqliteDatabase = this.getWriteableDatabase();
sqliteDatabase.update(TABLE_NAME,
cv,
COL1+"=?",
new String[]{Long.toString(id)}
);
}
如果您只想更新某些列但仍使用一种方法,则:-
public void updateAll(int id,
String newName, String oldName
String newAuth,
String newUser,
String newLocation) {
ContentValues cv = new ContentValues();
if (newName != null && newName.length() > 0) {
cv.put(COL2,newName);
}
if (newAuth != null && newAuth.length() > 0) {
cv.put(COL3,newAuth);
}
if (newLocation != null && newLocation.length() > 0) {
cv.put(COL4,newLocation);
}
if (newUser != null && newUser.length() > 0) {
cv.put(COL5,newUser);
}
if (cv.size() > 0) {
SqliteDatabase sqliteDatabase = this.getWriteableDatabase();
sqliteDatabase.update(TABLE_NAME,
cv,
COL1+"=?",
new String[]{Long.toString(id)}
);
}
}
例如
yourdbhelper.updateAll(id, "Fred","",null,"France");
将 :-
如果您只想更新旧的??? 匹配的值,则可以使用:-
public void updateAll(int id,
String newName, String oldName,
String newAuth, String oldAuth,
String newUser, String oldUser,
String newLocation, String oldLocation) {
ArrayList<String> whereargs = new ArrayList<>(Arrays.asList(String.valueOf(id)));
StringBuilder whereclause = new StringBuilder(COL1+"=?");
if(oldName != null && oldName.length > 0) {
whereclause.append(" AND " + COL2 + "=?");
whereargs.add(oldName);
}
if(oldAuth != null && oldAuth.length > 0) {
whereclause.append(" AND " + COL3 + "=?");
whereargs.add(oldAuth);
}
if(oldUser != null && oldUser.length > 0) {
whereclause.append(" AND " + COL4 + "=?");
whereargs.add(oldUser);
}
if(oldLocation != null && oldLocation.length > 0) {
whereclause.append(" AND " + COL5 + "=?");
whereargs.add(oldLocation);
}
ContentValues cv = new ContentValues();
if (newName != null && newName.length() > 0) {
cv.put(COL2,newName);
}
if (newAuth != null && newAuth.length() > 0) {
cv.put(COL3,newAuth);
}
if (newLocation != null && newLocation.length() > 0) {
cv.put(COL4,newLocation);
}
if (newUser != null && newUser.length() > 0) {
cv.put(COL5,newUser);
}
if (cv.size() > 0) {
SqliteDatabase sqliteDatabase = this.getWriteableDatabase();
sqliteDatabase.update(TABLE_NAME,
cv,
whereclause.toString(),
whereargs.toArray(new String[whereargs.size()])
);
}
}
!请注意,该代码是原则性的,尚未经过测试,因此可能存在一些错误。
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