使用SQL查询的Andr​​oid Where子句问题子句、问题、Andr、SQL

2023-09-07 04:49:04 作者:6个字的优雅好听相关文章>>

我有以下的code创建我的表。我将数据插入到它,看起来像这样

I have the following code that creates my table. I insert data into it that looks like this

_id     date     recordName     total
--------------------------------------
7      2011     TestMaxRecord     5

Java的code:

Java code:

public static final String KEY_ROWID = "_id";   
public static final String KEY_DATE = "date";
public static final String KEY_TOTAL = "total";
public static final String KEY_RECORD_NAME = "recordName";

private static final String DATABASE_CREATE_RECORDS = "create table " + DATABASE_TABLE_RECORDS + " (" 
+ KEY_ROWID + " integer primary key autoincrement, " 
+ KEY_DATE + " text not null, "
+ KEY_RECORD_NAME + " text not null, "
+ KEY_TOTAL + " text not null);";

public Cursor getRecord(String name) throws SQLException {
  return mDb.query(true, DATABASE_TABLE_RECORDS, new String[] {KEY_ROWID, KEY_DATE, KEY_RECORD_NAME, KEY_TOTAL}, KEY_RECORD_NAME + " = " + name, null, null, null, null, null);
}

据每次抛出一个异常,其中name =TestMaxRecord(尽管那里是在那里的数据),出现以下错误

It throws an exception every time where name = "TestMaxRecord" (despite there being data in there) with the following error

android.database.sqlite.SQLiteException:没有这样的列:TestMaxRecord:在编制:SELECT DISTINCT _id,日期,recordName,共有来自记录中,其中recordName = TestMaxRecord

android.database.sqlite.SQLiteException: no such column: TestMaxRecord: , while compiling: SELECT DISTINCT _id, date, recordName, total FROM Records WHERE recordName=TestMaxRecord

看起来像是对我说,它正在寻找一个列标题 TestMaxRecord 。我是一个Android新手,但(这是虽然使用INT)复制这部分pretty的多少完全由一个例子。是否有使用int和字符串您的查询之间的差异?

Which looks like to me that it is looking for a column title TestMaxRecord. I am an android newbie but copied this portion pretty much exactly from an example (it was using int though). Is there a difference between using int and Strings on your query?

推荐答案

您需要把单引号围绕价值,否则就会把它当作一列。

You need to put single quotes around the value, otherwise it will treat it as a column.

KEY_RECORD_NAME + " = '" + name + "'"

注:该解决方案是开放的SQL注入,你应该使用参数占位符,并通过 selectionArgs两个参数传递的值:

public Cursor getRecord(String name) throws SQLException {
  return mDb.query(true, 
    DATABASE_TABLE_RECORDS, 
    new String[] {KEY_ROWID, KEY_DATE, KEY_RECORD_NAME, KEY_TOTAL}, 
    KEY_RECORD_NAME + " = ?",
    new String[] {name},
    null, null, null, null);
}

另外,考虑SQLiteQueryBuilder

 
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