How to write WHERE IN clause from a dynamic ArrayList for Android SQLite query

Question

How can i write the where in clause in Android SQLite query?

Function to retrieve a single customer

public Cursor getCustomers(int groupId) {
    return db.query(TABLE_CUSTOMERS, new String[] { KEY_CUSTOMER_ID, KEY_NAME}, KEY_GROUP_ID+" = "+groupId, null, null, null, null);
}

Function to retrieve a more customers

public Cursor getCustomers(ArrayList<Integer> groupIds) {
    // Need to apply SELECT id, name FROM customers WHERE id IN (11, 13, ...18);
    //return db.query(TABLE_CUSTOMERS, new String[] { KEY_CUSTOMER_ID, KEY_NAME}, KEY_GROUP_ID+" = "+groupIds, null, null, null, null);
}

The size of the groupId ArrayList is dynamic.

Answer 1

You can use the Android TextUtils class join method to make a comma separated list of IDs to put in the in clause.

String selection = KEY_GROUP_ID + " IN (" + TextUtils.join(", ", groupIds) + ")";
return db.query(TABLE_CUSTOMERS, new String[] { KEY_CUSTOMER_ID, KEY_NAME}, selection, null, null, null, null);

BTW if groupIds is a list of primary keys from another table you should be using Longs to store them not Integers otherwise it will overflow when the IDs get large.