Question

我遇到了问题：

Caused by: android.database.sqlite.SQLiteException: near "SELECT": syntax error (code 1): , while compiling: SELECT tags FROM appDb_table_project WHERE SELECT DISTINCT tags

我有：

public static final String DB_NAME = "appDbProject";
public static final int DB_VERSION = 1;
public static final String DB_TABLE = "appDb_table_project";

public static final String COLUMN_ID = "_id";
public static final String COLUMN_NAME = "name";
public static final String COLUMN_DESCRIPTION = "description";
public static final String COLUMN_TAGS = "tags";

public SQLiteDatabase mDB;
public Cursor getTags() {
    String[] column = new String[] { COLUMN_TAGS };
    //return mDB.query(DB_TABLE, column, "SELECT DISTINCT tags", null, null, null, null);
    //return mDB.query(true, DB_TABLE, new String[] { COLUMN_TAGS }, null, null, COLUMN_TAGS, null, null, null);
    //String query ="SELECT DISTINCT tags FROM appDb_table_staff";
    //return mDB.rawQuery(query, null);
    return mDB.query(true, DB_TABLE, new String[] { COLUMN_TAGS }, null, null, COLUMN_TAGS, null, null, null);
}

我正在尝试将SELECT DISTINCT语句用于字段“tags”中的数据并将其放入String []中，但我没有得到。

Cursor cursor = db.getTags();
    String[] array = new String[cursor.getCount()];
    int i = 0;
    while (cursor.moveToNext()) {
        String tag = cursor.getString(cursor.getColumnIndex("tags"));
        array[i] = tag;
        i++;
    }
    String[] from = array;
    int[] to = new int[] { R.id.textViewTags };

我尝试了不同的选项，但永远我在这一行和我的方法“getTags”中得到了这个错误：

Cursor cursor = db.getTags();

我做错了什么？

UPD：

实际执行的代码： code 1 code 2

Answer 1

只需更改以下行：

SELECT tags FROM appDb_table_project WHERE SELECT DISTINCT tags

到

SELECT tags FROM appDb_table_project

Answer 2

尝试添加＆＃34;空间＆＃34;

public Cursor getTags() {
String[] column = new String[] { COLUMN_TAGS };
//return mDB.query(DB_TABLE, column, " SELECT DISTINCT tags ", null, null, null, null);
//return mDB.query(true, DB_TABLE, new String[] { COLUMN_TAGS }, null, null, COLUMN_TAGS, null, null, null);
//String query =" SELECT DISTINCT tags FROM appDb_table_staff ";
//return mDB.rawQuery(query, null);
return mDB.query(true, DB_TABLE, new String[] { COLUMN_TAGS }, null, null, COLUMN_TAGS, null, null, null);
 }

“SELECT”附近：语法错误（代码1）

2 个答案: