react-native-sqllite value not displayed

Question

this.getDetails();

getDetails = () => {
     let userDetails = [];
     db.transaction((tx) => {
          tx.executeSql('select * from users where role=?',['students'],(tx,results) => {
               let details = []
               if(results.rows.length > 0){
                    for(let i=0; i < results.rows.length; i++){
                          details.push(results.rows.item(i));
                    }
               }
               userDetails = details;
               //Data is displayed  here
               console.log(userDetails)
          })
     })
     // Data is not printed here
     console.log(userDetails) // []
}

In the above code snippet , I am able to get the data(userDetails) inside the tx.executeSql but not outside the db.transaction block.

Can anyone please help me out how to display the data outside of the db.transaction block.

Answer 1

Define a promise function for getting userDetails from DB.

async dbAction = () => {
  return new Promise((resolve, reject) => {
    db.transaction((tx) => {
          tx.executeSql('select * from users where role=?',['students'],(tx,results) => {
               let details = []
               if(results.rows.length > 0){
                    for(let i=0; i < results.rows.length; i++){
                          details.push(results.rows.item(i));
                    }
               }
               //Data is displayed  here
               resolve(details);
          })
     })
  });
}

And then you can call it like this.

getDetails = () => {
     let userDetails = [];
     try {
       let userDetails = await dbAction();
       console.log(userDetails);
     } catch (e) {
     }
}