public void DBSearchCategory(String tableName) {
// 1st way
String inClause = s1.ListViewCategory.toString();
inClause = inClause.replace("[", "(");
inClause = inClause.replace("]", ")");
// Cursor cursor = database.rawQuery("SELECT CATEGORY FROM " + tableName
// + " WHERE CATEGORY NOT IN " + inClause
// + " ORDER BY RANDOM() LIMIT 1 ", null);
// 2nd way
try {
StringBuilder sb = new StringBuilder("");
for (String param : s1.ListViewCategory) {
sb.append(",").append('"').append(param).append('"');
}
params = sb.toString().substring(1);
Log.v("Tag", "params value is " + params);
} catch (StringIndexOutOfBoundsException e) {
}
Cursor cursor = database.rawQuery("SELECT CATEGORY FROM " + tableName
+ " WHERE CATEGORY NOT IN (?) "
+ " ORDER BY RANDOM() LIMIT 1 ", new String[]{params});
while (cursor.moveToNext()) {
category = cursor.getString(cursor.getColumnIndex("CATEGORY"));
s1.keyCategory = category;
}
cursor.close();
}
s1.ListViewCategory is a String type ArrayList in Singleton class s1, and it has values of categories: "game","country","city","subway","actor","pet" // In Database there are total 33 categories, and I want to exclude these 6 categories that are in s1.ListViewCategory
In rawQuery, I want to exclude categories that are in s1.ListViewCategory, so I tried 2 ways of cursor refering to these 2 stackoverflow questions: Android - sqlite in clause using string values from array? ///Android - sqlite in clause using values from array
I used WHERE and NOT IN statement to exclude these 6 categories
When I tried 2nd way cursor, I got no error. However, the Sql query did not work. It had to exclude categories that are in String[params], but it did not work. So I used log to see what param is and I got this
2020-01-09 09:16:47.233 8978-8978/com.kj.word V/Tag: params value is "game","country","city","subway","actor","pet"
When I tried 1st Cursor Category, I got error logcat:
Error Code : 1 (SQLITE_ERROR)
Caused By : SQL(query) error or missing database.
(no such column: game (code 1): , while compiling: SELECT CATEGORY FROM KeyWordDB WHERE CATEGORY
NOT IN (game, country, city, subway, actor, pet) ORDER BY RANDOM() LIMIT 1)
#################################################################
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:1008)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:573)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:59)
at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
at android.database.sqlite.SQLite
I confirmed that there is a database, so I guess it is probably sql query problem ...
I've searched real hard, but I wasn't able to find answer... Ill be real grateful, if someone answers this question
Change the double quotes with single quotes inside the loop that constructs the comma delimited list:
for (String param : s1.ListViewCategory) {
sb.append(",").append("'").append(param).append("'");
}
params = sb.toString().substring(1);
This code constructs a list like:
'game', 'country', 'city', 'subway', 'actor', 'pet'
If you use it as a parameter in the rawQuery()
method then this list will be treated as a string literal and not a list of values.
So do this instead:
String sql = "SELECT CATEGORY FROM " + tableName
+ " WHERE CATEGORY NOT IN (?) "
+ " ORDER BY RANDOM() LIMIT 1 ";
sql = sql.replace("?", params);
Cursor cursor = database.rawQuery(sql, null);
Note that this method is prone to sql injection.
Another way is to create a list of ?
placeholders instead of 1 placeholder and pass the list of values as an array of strings like this:
for (String param : s1.ListViewCategory) {
sb.append(",?");
}
String[] array = ListViewCategory.toArray(new String[s1.ListViewCategory.size()]);
params = sb.toString().substring(1);
String sql = "SELECT CATEGORY FROM " + tableName
+ " WHERE CATEGORY NOT IN (@) "
+ " ORDER BY RANDOM() LIMIT 1 ";
sql = sql.replace("@", params);
Cursor cursor = database.rawQuery(sql, array);