SQLite with expo-sqlite in React Native - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to open a SQLite database named 'mydb.db'.

React Native

import * as SQLite from 'expo-sqlite';
const db = SQLite.[1]('mydb.db');

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AopenDatabase

BcreateDatabase

CconnectDatabase

DinitDatabase

Attempts:

3 left

💡 Hint

Common Mistakes

Using createDatabase instead of openDatabase causes an error because it does not exist.

Trying to use connectDatabase or initDatabase which are not functions in expo-sqlite.

The function openDatabase is used to open or create a SQLite database in expo-sqlite.

2fill in blank

medium

Complete the code to execute a SQL query that creates a table named 'users' with columns 'id' and 'name'.

React Native

db.transaction(tx => {
  tx.executeSql('CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY NOT NULL, name TEXT);', [], [1]);
});

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A() => console.log('Table created')

Bnull

C() => alert('Error')

D() => console.error('Failed')

Attempts:

3 left

💡 Hint

Common Mistakes

Passing null instead of a function causes no feedback on success.

Using error callbacks in place of success callbacks.

The third argument to executeSql is a success callback function. Here, a simple console log confirms table creation.

3fill in blank

hard

Fix the error in the code to insert a user with name 'Alice' into the 'users' table.

React Native

db.transaction(tx => {
  tx.executeSql('INSERT INTO users (name) VALUES ([1]);', ['Alice']);
});

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A'Alice'

B:name

C?

D"Alice"

Attempts:

3 left

💡 Hint

Common Mistakes

Putting the value directly in the query causes SQL injection risk and errors.

Using ':name' which is not supported by expo-sqlite.

The SQL query must use a placeholder '?' for the value to be inserted safely using parameters.

4fill in blank

hard

Fill both blanks to query all users and log their names.

React Native

db.transaction(tx => {
  tx.executeSql('SELECT * FROM users;', [], (tx, [1]) => {
    for (let i = 0; i < [2].rows.length; i++) {
      console.log([2].rows.item(i).name);
    }
  });
});

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Aresults

Bresponse

CresultSet

Ddata

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inconsistently causes errors.

Trying to access rows on the transaction object instead of results.

The second argument of the success callback is commonly named 'results' and contains the rows property with the query results.

5fill in blank

hard

Fill all three blanks to update a user's name by id and handle success and error.

React Native

db.transaction(tx => {
  tx.executeSql('UPDATE users SET name = [1] WHERE id = [2];', ['Bob', 1], [3], error => console.error(error));
});

Drag options to blanks, or click blank then click option'

A'?'

B?

C() => console.log('Update successful')

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around '?' makes it a string literal, not a placeholder.

Passing null instead of a success callback loses feedback on success.

Use '?' placeholders for parameters in the SQL query. The third argument is the success callback function.