1. Lecture 8: Database
Topics: Basic SQLite Operations

2. Today’s class: Concepts Database, Table, Primary Key (Lecture)
SQL Commands
Android
(code)
Example of “Characters” database
Create, Insert, Delete, Query

3. Database
Bunch of tables having column headers where you store data—one datum in each row.
Table: Characters
Table: Appearance ID
Name
Home 1
John
Winterfell 2
Tyrion
Casterly Rock 3
Daenerys
Dragon Stone
Episode
CharacterID
Appeared 1 10 2 5 3 7 9
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4. Create and Drop Tables
SQL:
CREATE TABLE Characters ( ID INT PRIMARY KEY, NAME TEXT, HOME TEXT );
Table: Characters ID
Name
Home
SQL:
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DROP TABLE IF EXISTS Characters;

5. Insert and Delete Rows
SQL:
Table: Characters
INSERT INTO Characters VALUES (1, ‘John’, ‘Winterfell’); VALUES (2, ‘Tyrion’, ‘Casterly Rock’); ID
Name
Home 1
John
Winterfell 2
Tyrion
Casterly Rock
SQL:
Table: Characters
DELETE FROM Characters
WHERE Name = ‘John’; ID
Name
Home 2
Tyrion
Casterly Rock
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6. Query SELECT * FROM Characters WHERE ID < 3;
SQL:
Table: Characters
SELECT * FROM Characters WHERE ID < 3; ID
Name
Home 1
John
Winterfell 2
Tyrion
Casterly Rock 3
Daenerys
Dragon Stone
SQL:
Table: Characters
SELECT Name, Episode, Appeared
FROM Characters, Appearance
WHERE ID = CharacterID
AND Episode = 1
AND Appeared < 7 ID
Name
Home
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7. Query SELECT Name, Episode, Appeared FROM Characters, Appearance
Table: Characters
SQL: ID
Name
Home 1
John
Winterfell 2
Tyrion
Casterly Rock 3
Daenerys
Dragon Stone
SELECT Name, Episode, Appeared
FROM Characters, Appearance
WHERE ID = CharacterID
AND Episode = 1
AND Appeared < 7
Table: Appearance
Episode
CharacterID
Appeared 1 10 2 5 3 7 9
Output:
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Name
Episode
Appeared
Tyrion 1 5

8. Android SQLite (in 3 lines)
What?
How?
Database
Open/Create
SQLiteDatabase
db = this.openOrCreateDatabase (“SomeDB", Context.MODE_PRIVATE, null);
Table Drop/Create Rows Insert/delete
db.execSQL(“A SQL COMMAND”);
Select
Cursor c = db.rawQuery("SELECT …. “);
c.moveToFirst();
c.getString(index);
c.moveToNext();
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9. References (study these)