CODEWITHSUNDEEP
javascriptnode.jssqlite
user1592380
user1592380

Reputation: 36367

Missing output from sqlite query

enter image description here

I'm working with node and sqlite using the sqlite3 npm package. I'm trying to run the following query in node:

 SELECT PropertyId FROM 'myData' WHERE Code IS NULL LIMIT 5

You can see that this works manually in the screenshot. In node I have

async function select_Rs_from_table(db,tablename, limit) {

// SELECT PropertyId FROM 'myData' WHERE Code IS NULL;

let out  
try {
 const sql = `SELECT PropertyId FROM '${tablename}' WHERE Code IS NULL LIMIT ${limit}`;
console.log(sql);
out =  await db.run(sql);
 
} catch (error) {
 console.log(error); 
}
return out;

}

When I run this with

const sqlite3 = require('sqlite3').verbose();
 // open the database
const db = new sqlite3.Database('./test.db', 
sqlite3.OPEN_READWRITE, (err) => {
  if (err) {
    console.error(err.message);
  }
  console.log('Connected to the database.');
});
console.log('here');

select_Rs_from_table(db, 'myData', 5).then(x => console.log(x));

I see:

Debugger attached.
SELECT PropertyId FROM 'myData' WHERE StateCode IS NULL LIMIT 5
Database {}
Connected to the database.
Waiting for the debugger to disconnect...

Where is the result? How to I access the expected output?

Upvotes: 0

Views: 394

Answers (1)

Zac Anger
Zac Anger

Reputation: 7787

There are a couple issues: you're using Promise-based calls with the sqlite3 package, but that package uses callbacks. You're also using db.run rather than db.get for a select statement. To use Promises (async/await) you need the sqlite package using sqlite3.Database as a driver. Please try this fixed example:

const sqlite3 = require('sqlite3').verbose()
const sqlite = require('sqlite')

;(async () => {
  const db = await sqlite.open({
    filename: './test.db',
    driver: sqlite3.Database
  })
  console.log('connected!')

  async function select_Rs_from_table(tablename, limit) {
    try {
      const sql = `SELECT PropertyId FROM '${tablename}' WHERE Code IS NULL LIMIT ${limit}`
      return await db.get(sql)
    } catch (error) {
      console.error(error)
    }
  }

  select_Rs_from_table('myData', 5).then(console.log)
})()

Upvotes: 1

Related Questions