我是Android的菜鸟,我正在尝试查询sqlite表。我已经阅读了几个教程并且知道如何查询表以返回整列值,但我似乎无法弄清楚如何从字符串中逐列查询单个值。任何帮助是极大的赞赏。这是我的代码:
我成功的代码来查询和返回整列的值:
public String getValue() {
// TODO Auto-generated method stub
String[] columns = new String[]{ KEY_ROWID, KEY_NAME, KEY_QUANTITY, KEY_OUNCES, KEY_VALUE };
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
String result = "";
int iRow = c.getColumnIndex(KEY_ROWID);
int iName = c.getColumnIndex(KEY_NAME);
int iQuantity = c.getColumnIndex(KEY_QUANTITY);
int iOunces = c.getColumnIndex(KEY_OUNCES);
int iValue = c.getColumnIndex(KEY_VALUE);
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
result = result + /*c.getString(iRow) + " " +*/ c.getString(iValue) + "\n";
}
return result;
}
我尝试按字符串查询列的单个值:
public String getSingleValue(String aCoin) throws SQLException{
// TODO Auto-generated method stub
String[] columns = new String[]{ KEY_ROWID, KEY_NAME, KEY_QUANTITY, KEY_OUNCES, KEY_VALUE};
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_NAME + "=" + aCoin, null, null, null, null);
String result = "";
int iRow = c.getColumnIndex(KEY_ROWID);
int iName = c.getColumnIndex(KEY_NAME);
int iQuantity = c.getColumnIndex(KEY_QUANTITY);
int iOunces = c.getColumnIndex(KEY_OUNCES);
int iValue = c.getColumnIndex(KEY_VALUE);
if (c != null){
c.moveToFirst();
result= c.getString(1);
return result;
}
return null;
}
答案 0 :(得分:0)
更改此
String[] columns = new String[]{ KEY_ROWID, KEY_NAME, KEY_QUANTITY, KEY_OUNCES, KEY_VALUE };
到
String[] columns = new String[]{ KEY_NAME};
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_NAME + "=" + aCoin, null, null, null, null);
String result = "";
if (c != null){
c.moveToFirst();
result= c.getString(0);
return result;
}
return null;
如果您只想获取名称列。