![]() In the next project, we’ll create a simple record-keeping sketch using the SQLite data management system, which can store a list of individual names and the IDs associated with them. Now let’s get started with our first KetaiSQLite database. SQL statement to make an integer field, which is typically also the primary key to automatically increment by one in order to be unique SQL statement to make a field the primary key SQL wildcard that stands for “all” in a query ![]() SQL statement to query a database, returning zero or more rows of data SQL statement for creating a new row in a table SQL statement for creating a table in a database with specified fields and data types Now let’s take a look at the most important declarative SQL we’ll use in our database project. KetaiSQLite method returning all records in a database across all tables KetaiSQLite method returning all records in a specified table, using the table name as parameter KetaiSQLite method for sending a SQLite query to a database, returning data ![]() KetaiSQLite method for executing a SQLite query to a database, which doesn’t return data Ketai class for working with SQLite databases-it can be used to create a KetaiSQLite database or to load an existing database. To use SQLite on the Android, we’ll work with the following KetaiSQLite methods. Let’s take a look at the KetaiSQLite class and SQLight basics. If you are unfamiliar with the language or would like to explore SQL queries further later on, you can find a more thorough reference online for the statements outlined next. The next project will take advantage of the KetaiSensor class to capture accelerometer data directly into a SQLite database, which we’ll browse and visualize on the Android display.įor the SQLite app we’ll create in this chapter, we’ll discuss SQL queries only very briefly. We’ll create two SQLite projects, one to get us up and running with a few random values in a SQLite database. Let’s get started by taking a look at the relevant Processing and Ketai methods we’ll be working with throughout the chapter. For the projects in this chapter, we’ll use it to store a number of points that we’ll create by tapping the touch screen interface, and later we’ll use it to record accelerometer sensor data using the KetaiSensor class we’ve seen in Chapter 3, Using Motion and Position Sensors. The Ketai KetaiSQLite class is what we need to create full-fledged local SQLite databases on the device. Ketai gives us access to Android’s SQLiteDatabase class and provides us with the essential methods we need to create, query, and update content in the database tables. It is based on the the popular Structured Query Language syntax for database queries and will look very familiar if you’ve worked with SQL before. Now that we’ve seen most of Processing’s Table features, it’s time we take a look at the widely used SQLite database management system for local clients. Let’s take a look at the classes and methods that allow us to use SQLitedatabases for more complex data-driven apps. Finally, we’ll query the data set we’ve recorded based on a certain device orientation we are looking for, and we’ll highlight the sensor value that matches our query criteria. We’ll use the recorded sensor values to create a time series visualization of the data. Then we’ll create an app that uses SQLite to capture accelerometer data from the sensor built into the Android. In this chapter, we’ll first get SQLite running with a simple sketch and learn how to use SQL queries to retrieve data from a SQLite table. This simple database management system can be used instead of disk files, like the tab- or comma-delimited text files we’ve worked with in Chapter 9, Working with Data, replacing them with ad-hoc SQLite disk files. It is often used in cellphones, tablet computers, set-top boxes, and appliances because SQLite does not require administration or maintenance. It works very well as a file format for applications like Computer-Aided Design ( CAD), financial software, and record keeping. ![]() It offers less fine-grained control over access to data than other systems like PostgreSQL or MySQL does, but it is simpler to use and administer, which is the main objective of the technology. SQLite is a fairly simple and fast system, is considered very reliable, and has a small footprint that can be embedded in larger programs. It implements the popular Structured Query Language ( SQL) syntax for database queries, which we can use to access data stored locally on our Android device. In this second part of our introduction to data, we’ll work with SQLite, the popular relational database management system for local clients such as the Android, used also by many browsers and operating systems to store data.
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