promise execution error nodejs javascript

Question

I am new to node js. I am using express framework with sequelize orm to connect with my mysql database

Here's the one of the API Call I wrote

1    expressApp.post('/api/account_lister', (req, res) => {
2        var temp_obj = {}
3        var temp_list = []
4        WAAccount.findAll({where:{user_id:1}})
5            .then((DBData) => {
6            if ( DBData!== null ){
7                for (var i = 0; i < DBData.length; i++) {
8                    let wa_account_name = DBData[i].dataValues.wa_account_name
9                    let wa_id = DBData[i].dataValues.wa_id
10                   WAProperties.findAll({where:{wa_id:wa_id}})
11                        .then((DBData) => {
12                        if ( DBData!== null){
13                            for (var i = 0; i < DBData.length; i++) {
14                                temp_list.push(DBData[i].dataValues.wa_property_name)
15                            }
16                            temp_obj[wa_account_name] = temp_list
17                            temp_list = []
18                            console.log(temp_obj)  
19                        }
20                    })
21                    }
22            }
23        })
24        console.log(temp_obj)   
25        res.json({ success: true, account_property_list: temp_obj }); return;
26    })

In the Above Code, WAAccount and WAProperties are the two tables in MySQL. In the above code, there is two then function. the function in the then is executed in async manner. So the variable temp_obj in line 24 returns empty. But in line 18, the temp_obj has values that were executed after line 24 due to it is inside in then function. I want the 24th line to be executed after the complete execution of then functions. how to make it. Help me with some solutions.

Move res.json inside .then()

slebetman
– slebetman

2020-03-26 07:38:21 +00:00
Commented Mar 26, 2020 at 7:38 — slebetman
– slebetman, Commented Mar 26, 2020 at 7:38

snak · Accepted Answer · 2020-03-26 05:47:07Z

1

You could do:

expressApp.post('/api/account_lister', async (req, res) => {
    var temp_obj = {}
    var temp_list = []
    const DBData = await WAAccount.findAll({where:{user_id:1}})   
    if ( DBData!== null ){
        for (var i = 0; i < DBData.length; i++) {
            let wa_account_name = DBData[i].dataValues.wa_account_name
            let wa_id = DBData[i].dataValues.wa_id
            const DBData2 = await WAProperties.findAll({where:{wa_id:wa_id}})
            if ( DBData2!== null){
                for (var i = 0; i < DBData2.length; i++) {
                    temp_list.push(DBData2[i].dataValues.wa_property_name)
                }
                temp_obj[wa_account_name] = temp_list
                temp_list = []
                console.log(temp_obj)          
            }
        }
    }
    console.log(temp_obj)   
    res.json({ success: true, account_property_list: temp_obj }); return;
})

edited Mar 26, 2020 at 5:47

snak

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answered Mar 26, 2020 at 5:45

dave

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