Android 更改sqlite中列中的值
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Change a value in a column in sqlite
提问by Gabrielle
I need to update a value in a column from a certain table. I tried this :
我需要更新某个表中列中的值。我试过这个：
public void updateOneColumn(String TABLE_NAME, String Column, String rowId, String ColumnName, String newValue){
String sql = "UPDATE "+TABLE_NAME +" SET " + ColumnName+ " = "+newValue+" WHERE "+Column+ " = "+rowId;
db.beginTransaction();
SQLiteStatement stmt = db.compileStatement(sql);
try{
stmt.execute();
db.setTransactionSuccessful();
}finally{
db.endTransaction();
}
}
and I call this method like this :
我这样称呼这个方法：
db.updateOneColumn("roadmap", "id_roadmap",id,"sys_roadmap_status_mobile_id", "1");
which means that I want to set the value 1in the column sys_roadmap_status_mobile_idwhen id_roadmap = id.
这意味着我要设置的值1列sys_roadmap_status_mobile_id时id_roadmap = id.
The problem is that nothing happens. Where is my mistake?
问题是什么都没有发生。我的错误在哪里？
回答by WarrenFaith
Easy solution:
简单的解决方案：
String sql = "UPDATE "+TABLE_NAME +" SET " + ColumnName+ " = '"+newValue+"' WHERE "+Column+ " = "+rowId;
Better solution:
更好的解决方案：
ContentValues cv = new ContentValues();
cv.put(ColumnName, newValue);
db.update(TABLE_NAME, cv, Column + "= ?", new String[] {rowId});
回答by BAIJU SHARMA
The below solution works for me for updating single row values:
以下解决方案适用于我更新单行值：
public long fileHasBeenDownloaded(String fileName)
{
SQLiteDatabase db = this.getWritableDatabase();
long id = 0;
try {
ContentValues cv = new ContentValues();
cv.put(IFD_ISDOWNLOADED, 1);
// The columns for the WHERE clause
String selection = (IFD_FILENAME + " = ?");
// The values for the WHERE clause
String[] selectionArgs = {String.valueOf(InhalerFileDownload.fileName)};
id = db.update(TABLE_INHALER_FILE_DOWNLOAD, cv, selection, selectionArgs);
}
catch (Exception e) {
e.printStackTrace();
}
return id;
}
