Transactions with node pg and foreach loop and async await












0















I am trying to insert multiple rows in PostgreSQL using node pg. I am using transactions but my query is executing after a response. I tried async await with my function but it is not working



This is my function



addPersons = async (req, res) => {
try {
await db.query("BEGIN");
req.body.forEach((person, index) => {
if (person.id) {
try {
await db.query("ROLLBACK");
} catch (error) {
console.error("Error rolling back client", err.stack);
}
return res
.status(Error_code.IdNotFound.code)
.send(Error_code.IdNotFound);
}
const query = `update person set
name = ${person.name},
where id = '${
person.id
}'`;
try {
await db.query(query);
} catch (error) {
try {
await db.query("ROLLBACK");
} catch (error) {
console.error("Error rolling back client", err.stack);
}
return res.status(500).send(err);
}
})
await db.query("COMMIT");
res.status(Error_code.Successfull.code).send(Error_code.Successfull);
} catch (error) {
try {
db.query("ROLLBACK");
} catch (error) {
console.error("Error rolling back client", err.stack);
}
return res
.status(Error_code.UnableToBeginTransaction.code)
.send(Error_code.UnableToBeginTransaction);
}
}


I also tried calling this function from another function and using foreach on that function but when whenever code detects await or callback in the second function it does not wait and return to the first function.
How can I run this code to add my data into PostgreSQL with transactions



Thanks










share|improve this question

























  • res.send should be after forEach. Why don't you split your code into promises ?

    – darklightcode
    Nov 19 '18 at 7:08






  • 1





    Possible duplicate of Using async/await with a forEach loop

    – estus
    Nov 19 '18 at 7:10











  • @darklightcode res.status is after foreach. I didn't used promise in my code till now. I have 2 scenarios where I need to handle this situation that's why I am trying to avoid promises

    – Unknown
    Nov 19 '18 at 8:24
















0















I am trying to insert multiple rows in PostgreSQL using node pg. I am using transactions but my query is executing after a response. I tried async await with my function but it is not working



This is my function



addPersons = async (req, res) => {
try {
await db.query("BEGIN");
req.body.forEach((person, index) => {
if (person.id) {
try {
await db.query("ROLLBACK");
} catch (error) {
console.error("Error rolling back client", err.stack);
}
return res
.status(Error_code.IdNotFound.code)
.send(Error_code.IdNotFound);
}
const query = `update person set
name = ${person.name},
where id = '${
person.id
}'`;
try {
await db.query(query);
} catch (error) {
try {
await db.query("ROLLBACK");
} catch (error) {
console.error("Error rolling back client", err.stack);
}
return res.status(500).send(err);
}
})
await db.query("COMMIT");
res.status(Error_code.Successfull.code).send(Error_code.Successfull);
} catch (error) {
try {
db.query("ROLLBACK");
} catch (error) {
console.error("Error rolling back client", err.stack);
}
return res
.status(Error_code.UnableToBeginTransaction.code)
.send(Error_code.UnableToBeginTransaction);
}
}


I also tried calling this function from another function and using foreach on that function but when whenever code detects await or callback in the second function it does not wait and return to the first function.
How can I run this code to add my data into PostgreSQL with transactions



Thanks










share|improve this question

























  • res.send should be after forEach. Why don't you split your code into promises ?

    – darklightcode
    Nov 19 '18 at 7:08






  • 1





    Possible duplicate of Using async/await with a forEach loop

    – estus
    Nov 19 '18 at 7:10











  • @darklightcode res.status is after foreach. I didn't used promise in my code till now. I have 2 scenarios where I need to handle this situation that's why I am trying to avoid promises

    – Unknown
    Nov 19 '18 at 8:24














0












0








0








I am trying to insert multiple rows in PostgreSQL using node pg. I am using transactions but my query is executing after a response. I tried async await with my function but it is not working



This is my function



addPersons = async (req, res) => {
try {
await db.query("BEGIN");
req.body.forEach((person, index) => {
if (person.id) {
try {
await db.query("ROLLBACK");
} catch (error) {
console.error("Error rolling back client", err.stack);
}
return res
.status(Error_code.IdNotFound.code)
.send(Error_code.IdNotFound);
}
const query = `update person set
name = ${person.name},
where id = '${
person.id
}'`;
try {
await db.query(query);
} catch (error) {
try {
await db.query("ROLLBACK");
} catch (error) {
console.error("Error rolling back client", err.stack);
}
return res.status(500).send(err);
}
})
await db.query("COMMIT");
res.status(Error_code.Successfull.code).send(Error_code.Successfull);
} catch (error) {
try {
db.query("ROLLBACK");
} catch (error) {
console.error("Error rolling back client", err.stack);
}
return res
.status(Error_code.UnableToBeginTransaction.code)
.send(Error_code.UnableToBeginTransaction);
}
}


I also tried calling this function from another function and using foreach on that function but when whenever code detects await or callback in the second function it does not wait and return to the first function.
How can I run this code to add my data into PostgreSQL with transactions



Thanks










share|improve this question
















I am trying to insert multiple rows in PostgreSQL using node pg. I am using transactions but my query is executing after a response. I tried async await with my function but it is not working



This is my function



addPersons = async (req, res) => {
try {
await db.query("BEGIN");
req.body.forEach((person, index) => {
if (person.id) {
try {
await db.query("ROLLBACK");
} catch (error) {
console.error("Error rolling back client", err.stack);
}
return res
.status(Error_code.IdNotFound.code)
.send(Error_code.IdNotFound);
}
const query = `update person set
name = ${person.name},
where id = '${
person.id
}'`;
try {
await db.query(query);
} catch (error) {
try {
await db.query("ROLLBACK");
} catch (error) {
console.error("Error rolling back client", err.stack);
}
return res.status(500).send(err);
}
})
await db.query("COMMIT");
res.status(Error_code.Successfull.code).send(Error_code.Successfull);
} catch (error) {
try {
db.query("ROLLBACK");
} catch (error) {
console.error("Error rolling back client", err.stack);
}
return res
.status(Error_code.UnableToBeginTransaction.code)
.send(Error_code.UnableToBeginTransaction);
}
}


I also tried calling this function from another function and using foreach on that function but when whenever code detects await or callback in the second function it does not wait and return to the first function.
How can I run this code to add my data into PostgreSQL with transactions



Thanks







node.js postgresql node-postgres






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 19 '18 at 8:01









Sayed Mohd Ali

8861318




8861318










asked Nov 19 '18 at 6:30









UnknownUnknown

328




328













  • res.send should be after forEach. Why don't you split your code into promises ?

    – darklightcode
    Nov 19 '18 at 7:08






  • 1





    Possible duplicate of Using async/await with a forEach loop

    – estus
    Nov 19 '18 at 7:10











  • @darklightcode res.status is after foreach. I didn't used promise in my code till now. I have 2 scenarios where I need to handle this situation that's why I am trying to avoid promises

    – Unknown
    Nov 19 '18 at 8:24



















  • res.send should be after forEach. Why don't you split your code into promises ?

    – darklightcode
    Nov 19 '18 at 7:08






  • 1





    Possible duplicate of Using async/await with a forEach loop

    – estus
    Nov 19 '18 at 7:10











  • @darklightcode res.status is after foreach. I didn't used promise in my code till now. I have 2 scenarios where I need to handle this situation that's why I am trying to avoid promises

    – Unknown
    Nov 19 '18 at 8:24

















res.send should be after forEach. Why don't you split your code into promises ?

– darklightcode
Nov 19 '18 at 7:08





res.send should be after forEach. Why don't you split your code into promises ?

– darklightcode
Nov 19 '18 at 7:08




1




1





Possible duplicate of Using async/await with a forEach loop

– estus
Nov 19 '18 at 7:10





Possible duplicate of Using async/await with a forEach loop

– estus
Nov 19 '18 at 7:10













@darklightcode res.status is after foreach. I didn't used promise in my code till now. I have 2 scenarios where I need to handle this situation that's why I am trying to avoid promises

– Unknown
Nov 19 '18 at 8:24





@darklightcode res.status is after foreach. I didn't used promise in my code till now. I have 2 scenarios where I need to handle this situation that's why I am trying to avoid promises

– Unknown
Nov 19 '18 at 8:24












1 Answer
1






active

oldest

votes


















0














Since this is tagged node-postgres, I suggest that you base your code on the A pooled client with async/await example in the node-postgres documentation. I also suggest that you use parameterized queries or a query builder such as mongo-sql. (There are many, but that one's my favourite. 🙂)



It could look something like this:



const { Pool } = require("pg");
const pool = new Pool();

const addPersons = async (req, res) => {
const db = await pool.connect();
try {
await db.query("BEGIN");
const query = `update person set name = $1 where id = $2;`;
// Promise.all() may improve performance here, but I'm not sure if it's safe
// or even useful in the case of transactions.
for (const person of req.body) {
await db.query(query, [person.name, person.id]);
}
await db.query("COMMIT");
} catch (e) {
await db.query("ROLLBACK");
throw e;
} finally {
db.release();
}
};





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    0














    Since this is tagged node-postgres, I suggest that you base your code on the A pooled client with async/await example in the node-postgres documentation. I also suggest that you use parameterized queries or a query builder such as mongo-sql. (There are many, but that one's my favourite. 🙂)



    It could look something like this:



    const { Pool } = require("pg");
    const pool = new Pool();

    const addPersons = async (req, res) => {
    const db = await pool.connect();
    try {
    await db.query("BEGIN");
    const query = `update person set name = $1 where id = $2;`;
    // Promise.all() may improve performance here, but I'm not sure if it's safe
    // or even useful in the case of transactions.
    for (const person of req.body) {
    await db.query(query, [person.name, person.id]);
    }
    await db.query("COMMIT");
    } catch (e) {
    await db.query("ROLLBACK");
    throw e;
    } finally {
    db.release();
    }
    };





    share|improve this answer




























      0














      Since this is tagged node-postgres, I suggest that you base your code on the A pooled client with async/await example in the node-postgres documentation. I also suggest that you use parameterized queries or a query builder such as mongo-sql. (There are many, but that one's my favourite. 🙂)



      It could look something like this:



      const { Pool } = require("pg");
      const pool = new Pool();

      const addPersons = async (req, res) => {
      const db = await pool.connect();
      try {
      await db.query("BEGIN");
      const query = `update person set name = $1 where id = $2;`;
      // Promise.all() may improve performance here, but I'm not sure if it's safe
      // or even useful in the case of transactions.
      for (const person of req.body) {
      await db.query(query, [person.name, person.id]);
      }
      await db.query("COMMIT");
      } catch (e) {
      await db.query("ROLLBACK");
      throw e;
      } finally {
      db.release();
      }
      };





      share|improve this answer


























        0












        0








        0







        Since this is tagged node-postgres, I suggest that you base your code on the A pooled client with async/await example in the node-postgres documentation. I also suggest that you use parameterized queries or a query builder such as mongo-sql. (There are many, but that one's my favourite. 🙂)



        It could look something like this:



        const { Pool } = require("pg");
        const pool = new Pool();

        const addPersons = async (req, res) => {
        const db = await pool.connect();
        try {
        await db.query("BEGIN");
        const query = `update person set name = $1 where id = $2;`;
        // Promise.all() may improve performance here, but I'm not sure if it's safe
        // or even useful in the case of transactions.
        for (const person of req.body) {
        await db.query(query, [person.name, person.id]);
        }
        await db.query("COMMIT");
        } catch (e) {
        await db.query("ROLLBACK");
        throw e;
        } finally {
        db.release();
        }
        };





        share|improve this answer













        Since this is tagged node-postgres, I suggest that you base your code on the A pooled client with async/await example in the node-postgres documentation. I also suggest that you use parameterized queries or a query builder such as mongo-sql. (There are many, but that one's my favourite. 🙂)



        It could look something like this:



        const { Pool } = require("pg");
        const pool = new Pool();

        const addPersons = async (req, res) => {
        const db = await pool.connect();
        try {
        await db.query("BEGIN");
        const query = `update person set name = $1 where id = $2;`;
        // Promise.all() may improve performance here, but I'm not sure if it's safe
        // or even useful in the case of transactions.
        for (const person of req.body) {
        await db.query(query, [person.name, person.id]);
        }
        await db.query("COMMIT");
        } catch (e) {
        await db.query("ROLLBACK");
        throw e;
        } finally {
        db.release();
        }
        };






        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 28 '18 at 9:49









        Carl von BlixenCarl von Blixen

        18917




        18917






























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